phytodoer@aol.com

Report Lists Non-Native Species in the U.S.

Several scientists at the United States Geological Service (USGS) have published a report and accompanying datasets that attempts to provide a publicly accessible and comprehensive list of non-native species established in United States.

Led by Annie Simpson and Meghan C. Eyler, a team of six scientists worked six years (2013–2018). They reviewed 1,166 authoritative sources to develop a list of 11,344 unique names – most of them binomials (genus and species), a few genera, plus some viruses.

This was a Herculean effort that produced very valuable products. We are all in their dept!

Simpson and Eyler point out that knowing which species are non-native to a region is a first step to managing invasive species. Lists compiled in the past were developed to serve a variety of purposes, including watch lists for preventing invasions, inventory and monitoring lists for research and modeling, regulatory lists for species control, and non-regulatory lists for raising awareness. As a result, they are not comprehensive.

Among the sources these authors consulted in preparing the list were peer-reviewed journal articles, books, brochures, circulars, databases, environmental assessments, technical reports, graduate theses, and websites.

Data – by Region

The report also notes which non-native species were established in each of three regions: the “lower 48” states, Alaska, and Hawai`i. Not surprisingly, more than half the non-native taxa are established in the vast area (nearly 7.9 million km²) comprising the “lower 48” states – 6,675 taxa. Almost half of the total number of non-native taxa have established in the tiny geographic region (only 28,311 km²) of Hawai`i – 5,848 taxa. One-tenth as many non-native taxa – 598 – are reported as established in Alaska (1.7 million km²).

This report includes taxa that are not native to any part of the specific region, but established (naturalized) somewhere in the region. An “established” species must have at least one population that is successfully reproducing or breeding in natural systems. The list includes domesticated animals and plants introduced for crops or horticulture when the taxon has escaped cultivation or captivity and become established in the wild. Species listed range from feral hogs (Sus scrofa) to plum pox virus and citrus canker to ohia rust (Puccinia psidii).

Of the total 11,344 taxa, 157 are established in all three regions. These included 125 vascular plants (especially grasses and asters); 13 arthropods, 11 mammals; 6 birds; 3 mollusks; 1 bryozoan. One of the ubiquitous plant species is tree of heaven (Ailanthus altissima). I find it entirely appropriate that the cover photo shows this tree – the photo was taken 8 miles from my home in Fairfax County, Virginia.

Nearly three-quarters (71.4%) of the non-native species in Alaska are plant species. More than half (59.7%) of the non-native species in the “lower 48” region are also plants. Nearly all the remainder of the non-native species in both regions are some kind of animal. Fungi constitute only 1.8% of the non-native species in the “lower 48” region; all the rest of the groups (Bacteria, Chromista, Protozoa, Virus) constitute less than 1% of the non-native species recorded in either region.

By contrast, in Hawai`i, animals make up 69.7% of the listed non-native species; most are invertebrates. Plants constitute 29.8% of the Hawaiian list.

Gaps, by Taxon

The authors recognize that invertebrates and microbes are under-represented because species are still being discovered; non-charismatic and difficult-to-identify species tend to be overlooked; and the species composition of any nation in this era of globalization is constantly subject to change.

I have noted some gaps among the pathogens: the absence of some of the Phytophthora that have been detected infecting shrubs and herbaceous plants in California, e.g., Phytophthora cambivora, siskiyouensis, tentaculata; and the “rapid ohia death” pathogens, Ceratocystis huliohia and C. lukuohia. Dr. Simpson is aware of these gaps and is soliciting sources to help add these organisms – especially the various Phytophthora species – to the next version of the list.

Simpson and Eyler note that the relative geographic distribution of the list at its current state seems to reinforce three well established premises: that tropical island systems are particularly vulnerable; that higher latitudes host fewer but are not invulnerable; and that species diversity in general decreases with increasing latitude.

Comparisons to Other Databases

After standardizing the names in the list by comparing them to the Integrated Taxonomic Information System (ITIS), Simpson and Eyler also reviewed the USGS BISON database, which has more than 381 million occurrence records for native and non-native species in the U.S. and Canada, covering 427,123 different taxa. (The BISON database contains significantly more species occurrences for the U.S. than the largest invasive species database, EDDMapS, which contained 4.4 million species occurrences as of June 2018.) Simpson and Eyler had to evaluate which of these taxa met their definition of non-native, since most species occurrence records in the USGS BISON are not labeled as non-native in the original records.

Comparing the BISON and non-native lists, Simpson and Eyler found that the BISON list contained a larger number of occurrence records for non-native taxa: a total of 13,450,515.However, the BISON list does not provide complete coverage of non-native species: it includes records for 77% of list of non-native species Simpson and Eyler found in Alaska, 75% of the “lower 48” sublist, but only 37% of the Hawaiian sublist.

Simpson and Eyler state their intention to continue updating the list of non-native species, they welcome contributions to it from area experts, and they urge integration of new occurrence data into invasive species database such as EDDMapS.

Indicators of Non-Native Species Richness

Figure 3 in the report (above) maps the number of non-native taxa in BISON at the county level. Figure 4 displays the proportion of non-native to native species in BISON. Higher percentages are generally evident in coastal areas and other regional hotspots. For example, the proportion in Hawaiian counties is greater than 33%. Additional data are needed to perform a more in-depth analysis of non-native species richness and abundance.

UPDATE! New Report in the Works

In June 2021, USGS announced that it was updating its Comprehensive List of Non-Native Species Established in 3 Major Regions of the U.S. so that the document more closely aligns with the parameters of the Global Register of Introduced and Invasive Species. The new USGS dataset is to be called the US Register of Introduced and Invasive Species. The list in the current draft includes 15,364 records. About 500 of these records are in Alaska, 6,000 in Hawai`i, and 8,700 in the conterminous 48 States.

One of the lead authors, Annie Simpson, contacted invasive species experts seeking feedback and suggested additions – based on authoritative resources such as peer reviewed journal articles, pest alerts, databases, books, and technical bulletins. She sought input by 25 July, 2021.

The published version of this dataset will be made freely available on USGS’ ScienceBase (https://www.sciencebase.gov), and all reviewers will be acknowledged in the dataset’s abstract.

SOURCE

Simpson, A., and Eyler, M.C., 2018, First comprehensive list of non-native species established in three major regions of the United States: U.S. Geological Survey Open-File Report 2018-1156, 15 p.

The report and accompanying data tables are available here.

South African report

In an unrelated but similar development, South Africa has issued a report on its invasive species — 2017 The Status of Biological Invasions and Their Management in South Africa. The report analyzes pathways of introduction and spread; number, distribution and impact of individual species; species richness and abundance of alien species in defined areas; and the effectiveness of interventions. The report notes that 775 invasive species have been identified to date, of which 556 are listed under some national regulatory program. Terrestrial and freshwater plants number 574 species; terrestrial invertebrates number 107 species. (This total does not include the polyphagous shot hole borer, which was detected too recently.) 107 species are considered by experts to be having either major or severe impacts on biodiversity and/or human wellbeing. Alien species richness is highest in the savanna, grassland, Indian Ocean coastal belt and fynbos biomes, lower in the more arid Karoo and desert biomes. South Africans are particularly focused on the reductions in surface water resulting from plant invasions. The decades-old “Working for Water” program has two goals: providing employment and development opportunities to disadvantaged individuals in rural areas, and managing invasive alien plants.

The Status of Biological Invasions and Their Management in South Africa is available here.

Posted by Faith Campbell

We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.

Worldwide – and U.S. – Proliferation of Phytophthora via the Nursery Trade – an Update

Phytophthora cinnanomi killing Ione manzanita in California; photo from Swiecki and Garbelotto, Distribution of Phytophthora cinnamomi within the range of Ione manzanita (Arctostaphylos myrtifolia). Agreement between the California Department of Fish and Game and University of California

Phytophthora species are plant pathogens in the oomycote group (water molds, closely related to brown algae). More than 160 species have been described; new species are continually being isolated. Many Phytophthora species are deadly to naïve hosts; examples in the United States include sudden oak death, Port-Orford cedar root disease, disease on chestnuts and oaks.

Forests in Europe – especially the United Kingdom – and Australia are also suffering high levels of mortality associated with one or more Phytophthora species.

In recent years, several studies have documented the role of nurseries in spreading non-native Phytophthora species. Two strains of P. ramorum are widespread in European nurseries and in tree plantations and wild heathlands of southwest England, Wales, parts of Scotland, and Ireland. (See here and here.)

In April 2016 I blogged about the situation in Europe described by Jung et al. 2015 (see references at the end of the blog). Jung et al. concluded that diseases caused by Phytophthora pose a substantial threat to both planted landscapes and forest ecosystems across Europe. They found 56 Phytophthora taxa in 66% of 2,525 forest and landscape planting sites that were probably introduced to those sites via nursery plantings.

Barber et al. 2013 reported nine species of Phytophthora associated with a wide variety of host species in urban streetscapes, parks, gardens, and remnant native vegetation in urban settings in Western Australia. Phytophthora spp were recovered from 30% of sampled sites.

A new summary confirms that the threat is similar in North America. In British Columbia, Dale et al. (2017) found more than two times as many Phytophthora species were detected in soil and water samples in urban areas (23) than in natural areas (11). Urban samples also showed a much higher diversity of Phytophthora per site than natural environments. These Phytophthora species had been introduced initially into urban areas and had subsequently spread into native vegetation, particularly in areas near developed sites (wildland-urban interface areas).

Swiecki et al 2018 cite several sources and their own studies to show that the large and increasingly diverse contingent of introduced Phytophthora species pose an increasingly important threat to both urban forests and surrounding native forests and plant communities in California. It is clear that shrubs and herbaceous plants as well as trees are also at risk. These scientists have repeatedly found multiple non-native Phytophthora species at individual sites in northern and southern California sites where nursery stock had been planted. Sampling in 2014 identified about 60 different Phytophthora taxa in restoration planting sites and native plant nurseries. The sampled restoration plantings were mostly located in urban riparian corridors and peri-urban parks, open spaces, or protected watersheds.

I first discussed this issue in a blog in July 2016.

Swiecki et al (2018) have also found that Phytophthora species persist in drier ecosystems. When conditions are too dry for sporangium production, Phytophthora hyphae produce resistant survival structures that can tolerate drying and persist in dead root fragments or soil. In the presence of appropriate stimuli, e.g., moisture and root exudates, resistant structures germinate to produce sporangia or hyphae, leading to new infections. Even relatively short wet periods associated with rain or irrigation can be sufficient to stimulate zoospore release. Swiecki et al (2018) list examples of numerous Phytophthora infestations that developed in dry sites, such as dry foothills of the Sierra Nevada in Amador County, and the Oakland Hills of Alameda & Contra Costa County. Swiecki et al. (2018) also note that P. cinnamomi has persisted in Australian forests in the absence of known primary hosts.

Phytophthora infections can also persist for decades in soil. In California, Swiecki et al. (2018) mention several examples:

Residual cinnamomi inoculum killed young sprouts of susceptible manzanitas (Arctostaphylos myrtifolia and A. viscida) planted on sites that were infected many years earlier.
A street planting of cork oaks (Quercus suber) apparently died due to Phytophthora root rot that had occurred 21 years earlier.
Both cinnamomi and P. cactorum were recovered from roots and soil beneath affected trees at least 60 years after the site had been a municipal woody plant nursery and adjacent residence.
A 7-acre area of native vegetation showing decline & mortality of multiple plant species was infested with multiple Phytophthora spp, including cactorum, P. cambivora, P. crassamura, P. ‘kelmania’ & P. syringae. The site was apparently infected 22 years earlier during a planting of a habitat restoration project using Ceanothus nursery stock. Subsequent spread was primarily downhill from the planting sites, facilitated by water flow, with additional spread along and near trails.

The Risk from the Nursery Trade

While Phytophthora-infested soil and plant debris can be transported on tools, vehicles, and shoes, or moved in large quantities when infested soil is excavated, graded, or imported, the principal threat is the nursery trade.

Jung et al. (2015) state that widespread contamination of nursery stock was the primary means by which these pathogens were introduced and spread in Europe. They found 49 Phytophthora taxa in 670 European nurseries. Phytophthora species were recovered from more than 90% of the sampled nurseries.
Swiecki et al. (2018) say that most of the common Phytophthora species detected in California are distributed globally, moved about with live plants or other infested materials. None is native to California.
Swiecki et al. (2018) cite studies reporting that thirteen species of Phytophthora were found in a survey for leaf spots in California nurseries in 2005 and 2006. Sampling of plants in or originating from Calif native plant nurseries alone has yielded about 60 Phytophthora At least eight species of Phytophthora were found in shipments of symptomatic and asymptomatic plants sent from west coast nurseries to Maryland. Parke et al. (2014) identified 28 Phytophthora taxa in four Oregon nurseries.
Not all infections are on the West Coast. Swiecki et al. (2081) reports that a survey in Minnesota nurseries of plants with symptoms – primarily on aboveground plant parts – found eleven species of Phytophthora.

Are scientists in other parts of the country looking for Phytophthora? I see no reason to think the situation in California is unique.

The damage caused by Phytophthora infections can be significant. In California and Oregon, sudden oak death, and Port-Orford cedar root disease, have killed well over a million trees and disrupted the ecosystems of which they are a part. There are multiple locations in Northern California where introduced Phytophthora species, especially P. cinnamomi and P. cambivora, have caused localized to extensive decline and mortality in native forests and shrublands.

Phytophthora dieback has infected more than one million hectares in Western Australia. More than 40% of the native plant species of the region are vulnerable to the causal agent, P. cinnamomi.

Phytophthora dieback in Western Australia

Dieback in native forest in Western Australia; photo copyright Western Australian Department of Parks and Wildlife

In the United Kingdom, several Phytophthora species are causing widespread mortality of native shrubs and trees and commercial plantings.

In nearly all the studies, scientists have detected previously unknown pathogen-host relationships.

The threat from spreading pathogens with wide host ranges is not limited to the genus Phytophthora. The fungus Fusarium euwallacea associated with the Kuroshio and polyphagous shot hole borers is known to kill at least 18 species of native plants in California and additional species in South Africa. The laurel wilt fungus kills many trees and shrubs in the Lauraceae family. ‘Ohi‘a or myrtle rust kills several shrubs native to Hawai`i and threatens a wide range of plants in the Myrtaceae family in Australia and New Zealand. Some insects also have wide host ranges, including the Kuroshio and polyphagous shot hole borers; and Asian longhorned and citrus longhorned beetles.

When are national and international phytosanitary agencies going to adopt policies and programs that are effective in preventing the continued spread of these highly damaging tree-killing pests? At the national level, APHIS needs to aggressively use two authorities to curtail importation of plant taxa from countries of origin which present a risk of transporting additional species of pathogens:

NAPPRA, which allows APHIS to prohibit risky imports until it has conducted a pest risk analysis.
Programs under the revised “Q-37” regulations allowing APHIS to work with exporting countries’ phytosanitary officials to implement integrated pest management strategies to ensure that plants are pathogen-free before they are exported.

I have blogged about both programs before – NAPPRA here; the Q-37 regulation strengthening here.

At the international level, the members of the International Plant Protection Convention (IPPC) must recognize the failure of the international phytosanitary system and explore ways to strengthen it. See my numerous blogs on this topic (beyond those linked to here!) by visiting www.cisp.us or www.nivemnic.us and searching under the category “forest pathogens”.

Posted by Faith Campbell

SOURCES

Jung, T. et al. 2015 “Widespread Phytophthora infestations in European nurseries put forest, semi-natural and horticultural ecosystems at high risk of Phytophthora disease” Forest Pathology. November 2015; available from Resource Gate

Swiecki, T.J., E.A. Bernhardt, and S.J. Frankel. 2018. Phytophthora root disease and the need for clean nursery stock in urban forests: Part 1 Phytophthora invasions in the urban forest & beyond. Western Arborist Fall 2018

Apparently can’t access current (2018) issues of “Western Arborist” on web unless subscribe

CISP Decision: EAB Deregulation Is Not Useful – Too Much Is at Risk

EAB; Dave Cappaert

I blogged about APHIS’ proposal to stop regulating movement of objects that can transport the emerald ash borer on 28 September. At that time, I and the Center for Invasive Species Prevention were undecided. Now we have taken a firm position: We are sympathetic to the situation in which APHIS finds itself and are disappointed that APHIS’ efforts against EAB have not been as successful as hoped. However, we believe the quarantine continues to serve a useful purpose in protecting North America’s ash (and through the firewood regulatory effort, other resources) and that the analysis APHIS provides does not justify the proposed termination of the regulatory program. Making this regulatory change, based on absent and questionable scientific data, would set a terrible precedent.

Problems Arising from Poorly Substantiated Proposal

Here I provide some additional information on points I made in the blog in September.

1) The APHIS documents are completely unbalanced. They provide no analysis of the economic or environmental impact of the regulatory changes that will allow the pest to spread more rapidly to the large areas of the country that are not yet infested.

The proposal concedes that emerald ash borer currently is known to occupy only about one quarter of the range of native Fraxinus species within the conterminous United States. As the Regulatory Flexibility Analysis states, numerous sawmills, firewood dealers, nurseries, logging/lumber companies, pallet manufacturing companies, and other establishments operate in these un-infested areas. The analysis makes no mention of the costs to millions of homeowners and property owners, thousands of municipal governments, etc., of removing and replacing ash trees on their properties that are killed by the ash borer as it spreads into new areas. The “analysis” makes no attempt to quantify impacts on any of these entities.

Examples of ash populations currently free of EAB include:

In North Dakota, 84% of the forest land area is dominated by hardwood forest types; one of the three major forest-type groups is elm/ash/cottonwood. Ash represent 38% of urban forest trees (Nowak, Hoehn, Crane, Bodine.)
In California, velvet ash (Fraxinus velutina) comprises 3.1% of the state’s street tree population (McPherson et al.). Because ash are large relative to other street trees, they provide about double the proportion of leaf cover (and associated environmental services) than the number of trees (Nowak, Hoehn, Crane, Weller, and Davila).
Portland, Oregon: ash represented 4% of urban trees (Portland Parks).

No mention is made of the additional range of Fraxinus species in Canada and Mexico that will be put at greater risk of invasion as the beetle spreads in the United States.

2) The proposal to rely on biocontrol to control EAB in the future lacks any scientific analysis of either the current biocontrol program’s effects or other possible program components.

APHIS is apparently relying on the conclusion by Duan et al. 2018 – based on models rather than field research findings – that larval and egg parasitism at about 60% would lead to a net population growth rate of EAB at a rate below replacement, therefore rapidly reducing EAB populations when such parasitism rates are accompanied by moderate to high levels of host plant resistance. If heavy woodpecker predation can be relied upon, a parasitism rate on EAB larvae of about 35% would be sufficient to achieve a similar reduction in the EAB population growth, even with limited levels of host resistance or tolerance.

However, scientific publications reviewing the impacts of the decade-old EAB biocontrol program present a mixed picture.

Our reading of several published studies indicate that two biocontrol agents (Oobius agrili and Tetrastichus planipennisi) appear to have established and spread in the northern reaches of the EAB’s U.S. range and southern Canada. At least some ash species appear to be regenerating well in some of those areas. However, it is too early to determine whether a third biocontrol agent (Spathius galinae) can protect the all-important remaining large trees, which have thicker bark. It is also too early to determine whether a different biocontrol agent (Spathius agrili) will have an impact on ash survival and regeneration in the middle latitudes (south of the 40^th parallel).

APHIS does not discuss current or planned future efforts to seek and test biocontrol agents more likely to thrive in the South and West – to which EAB will spread. It is hoped – but not yet proved – that S. agrili will be more effective south of the 40^th parallel. The article said nothing about possible agents that might be effective farther south or especially in the West.

Some scientists question the probable efficacy of biocontrol. For example, Showalter et al. note that “Despite the presence of a full complement of coevolved natural enemies in Asia, EAB has caused high mortality of North American ash species planted there … Biological control is best applied to systems in which the hosts can at least partially resist or tolerate non-native PIP [phytophagous insects and phytopathogens] attack, especially if negative density-dependent responses of natural enemies are slow relative to how long it takes the non-native PIP to kill trees.” Even Duan et al. 2018 agree that Asian ash species are more resistant (although they emphasize the large impact of natural enemies in Asia).

The scientific literature indicates that the impacts of egg parasitoid O. agrili remain uncertain (Abell et al.).

Duan et al. 2018 list and provide brief evaluations of nine possible biocontrol agents:

2: status not revealed (Sclerodermus pupariae, Atanycolus nigriventris)
2: disappointing efficacy to date (Spathius agrili, Oobius agrili)
1: apparently efficacious in some geographies in smaller trees only (Tetrastichus planipennisi)
1: promising in northern parts of EAB range but too early to evaluate (Spathius galinae)
2: considered to have too broad a host range to be released (Tenerus, Xenoglena quadrisignata)
1: release delayed pending further study (Oobius primorskyensis)

Even the impact of the most promising agent, Tetrastichus planipennisi, is not altogether clear. Duan et al. 2018 cite their life table analyses as indicating that T. planipennisi has contributed significantly to reducing net EAB population growth rates. They note a 90% reduction in EAB larval density. However, they say that this decline might be attributed in part to either the impact of the parasitoid or the general collapse of EAB populations following widespread mortality of overstory ash. (emphasis added)

3) Neither the proposal nor the supplementary materials provides any information about the current allocation of available funding among APHIS’ program components or how those allocations will change if the proposal is adopted.

For example, APHIS has set a goal of releasing biocontrol agents in every county with a known EAB infestation where the agent populations can be sustained. The proposal states that, by the end of the 2017 field season, parasitoids had been released in 27 of 32 states and 2 of 3 provinces in which EAB is present (Duan et al. 2018). APHIS does not explain how the current funding allocation hampers achieving the stated goal.

4) The proposal and accompanying regulatory flexibility analysis provide no information about whether APHIS will expand efforts supporting such other EAB impact minimization strategies as breeding trees resistant to emerald ash borer attack.

Even biocontrol practitioners (e.g., Duan et al. 2018 ) point to the importance of including breeding of resistant trees in the future efforts.

5) The proposal offers only vague promises about continuing federal efforts to minimize the risk that human transport of firewood will facilitate spread of the emerald ash borer or other tree pests.

Unfortunately, the impact of an outreach message depends heavily on having a simple, straightforward, unified message. Absent the EAB quarantine, which provides a nation-wide standard for firewood treatment, the “Don’t Move Firewood” campaign will be confronted by the task of trying to explain diverse messages and policies/rules issued by various states, counties, provinces, and managers of parks and other public lands. Hampered by this welter of messages, even the well-managed DMF campaign will struggle to persuade the public to help curtail spread via this pathway.

APHIS today published a set of “frequently asked questions” that address some of the issues raised in this blog. Go here to read the answers.

The Center for Invasive Species Prevention urges all who care about protecting North America’s native flora from non-native insects and diseases to submit comments on this proposed rule before the deadline on 19 November. This can be done by visiting here http://www.regulations.gov/#!docketDetail;D=APHIS-2017-0056.

Posted by Faith Campbell

SOURCES

Abell, K.J., L.S. Bauer, J.J. Duan, R. Van Driesche. 2014. Long-term monitoring of the introduced emerald ash borer (Coleoptera: Buprestidae) egg parasitoid, Oobius agrili (Hymenoptera: Encyrtidae), in MI, USA and evaluation of a newly developed monitoring Technique. Biological Control 79 (2014) 36–42

Duan, J.J., L.S. Bauer, R.G. van Driesche, and J.R. Gould. 2018. Progress & Challenges of Protecting North American Ash Trees from the emerald ash borer Using Biological Control. Forests 2018, 9, 142; doi:10.3390/f9030142

McPherson, G., N. van Doorn, J. de Goedec. 2016. Structure, function and value of street trees in California, USA. USDA Forest Service, Pacific Southwest Research Station Urban Forestry and Urban Greening 17 2016 (104-115)

Nowak, D.J., R.E. Hoehn III, D.E. Crane, A.R. Bodine. Assessing Urban Forest Effects and Values of the Great Plains: Kansas, Nebraska, North Dakota, South Dakota. USDA Forest Service Northern Research Station Resource Bulletin NRS-71

Nowak, D.J., R.E. Hoehn III, D.E. Crane, L. Weller, A. Davila. Assessing Urban Forest Effects and Values: Los Angeles’ Urban Forest. USDA Forest Service Northern Research Station Resource Bulletin NRS-47

Portland Parks and Recreation Street Tree Inventory Findings 2015. www.portlandoregon.gov/parks/treeinventory

Showalter, D.N., K.F. Raffa, R.A. Sniezko, D.A. Herms, A.M. Liebhold, J.A. Smith, P. Bonello. 2018. Strategic Development of Tree Resistance Against Forest Pathogen and Insect Invasions in Defense-Free Space. Frontiers in Ecology & Evolution

Scientists Document Alarming Declines in Insects

Luquillo Forest in Puerto Rico

While I usually blog about insects (and plant pathogens) that have invaded new ecosystems and are killing native plant species, I am aware that insects are numerous and vitally important components of the ecosystems in which they evolved. I join others in noting with concern evidence that insect populations in wide-apart areas have declined at very high rates. Insects appear to be affected by the Sixth Extinction Event (concept described here and here) as much as or possibly more than various vertebrate and plant taxonomic groups.

The Zoological Society of London and World Wildlife Fund published this week the 2016 version of the Living Planet report. Based on an analysis of 3,700 vertebrate species (birds, fish, mammals, amphibians and reptiles), the authors concluded that global wildlife populations have fallen by 58% since 1970 (Morelle; see references at the end of the blog).

Dirzo et al. in 2014 provided a very interesting discussion of the impacts of species’ declines in numbers and local extinctions – short of complete extinction. They asserted that “declines in numbers of individuals in local populations and changes in the composition of species in a community will generally cause greater impacts on ecosystem function than global extinctions. Dirzo et al. noted the importance of invertebrates, especially insects, in ecosystem functioning. They stated that the smaller fauna – including insects – “arguably are more functionally important” than charismatic megafauna and called for improved monitoring and study of such taxa, particularly invertebrates,

In their study, Dirzo et al. estimated that, since 1970, Lepidoptera – an order containing many important pollinators – had declined 35% in abundance globally over 40 years. Declines of other insect orders were considerably more. One study they cited found an overall 45% decline for all invertebrate populations over 35 years. More recent studies find decline rates that considerably exceed the estimated decline of 58% in global abundance of wild vertebrates over a 42-year period (Morelle; Hallmann et al.)

A year ago, Hallmann et al. reported a 76% decline in the biomass of flying insects over a 27-year period in Germany. There were seasonal variations; in midsummer, when insect biomass is highest, the decline was 82%. The study was carried out in nature protection areas – that is, places set aside and protected to conserve biological diversity. Hallmann et al. predict cascading effects on food webs and jeopardy to ecosystem services, including pollination, herbivory and breakdown of detritus, nutrient cycling and providing a food source for higher trophic levels such as birds, mammals and amphibians.

Hallmann et al. said that changes in weather, land use, and habitat characteristics could not explain this overall decline. Declines occurred in both nutrient-poor habitat types (e.g., heathlands, sandy grasslands, and dunes) and nutrient-rich habitats (grasslands, margins and wasteland), as well as in pioneer and shrub communities.

Another of the few studies looking at insects broadly, a study of flying insect biomass in the United Kingdom, found a biomass decline at only one of the four sites. Hallmann et al. note that the British researchers used considerably different sampling methods that targetted primarily high-flying insects (and caught mostly members of one fly family) whereas their own Malaise traps caught insects flying close to the ground and a much wider diversity of taxa.

Taxon-specific studies have also found severe declines in insect populations.

Hallmann et al. concluded that the scale of decline in insect biomass – throughout the growing season, and irrespective of habitat type or landscape configuration – suggest that large-scale factors must be involved. As noted, their data did not support either landscape changes or climate change as explanatory factors – although they admit that they did not exhaustively analyze the full range of climatic variables that could potentially impact insect biomass. Hallmann et al. did think that agricultural intensification (e.g. pesticide usage, year-round tillage, increased use of fertilizers and frequency of agronomic measures) was a plausible cause of insect biomass decline given the reserves’ limited size in typically fragmented western-European landscapes. The noted that the protected areas might serve as insect sources which might be counterbalanced by the surrounding agricultural fields, which might act as sinks or ecological traps.

While Hallman et al. did not specify the types of pesticides being used by the German farmers operating near their study areas, in recent years there has been growing concern about widespread use of neonicotenoids, which appear to pose a threat to bees and possibly other insects. Three sources of information are the European Food Safety Agency; Xerxes Society; and petition pertaining to regulation of seeds treated by neonicotenoids submitted by the Center for Food Safety.

This month, Bradford Lister and Andrés García published a study that compared numbers of the insects and insectivores (birds, frogs, lizards) in Puerto Rico’s tropical rainforest in 2012 to results of Lister’s studies there in 1976 and 1977. Overall arthropod biomass in Puerto Rico’s Luquillo rainforest fell 10 to 60 times since 1970s (Lister and Garcia). Numbers of insects in the vegetation collected by sweep nets decreased to a fourth or an eighth of what they had been. The catch rate of ground-dwelling arthropods caught in sticky traps fell 60-fold (Guarino).

Lister and Garcia attribute the crash in arthropod numbers to climate change, especially rising maximum temperatures. They note that over the same 40-year period, the average high temperature in the rainforest increased by 4 degrees Fahrenheit (2^oC). Lister and Garcia cite several studies indicating that tropical invertebrates are adapted to a narrow band of temperatures.

Lister and Garcia also measured declines among insect-feeding vertebrates. The biomass of anole lizards dropped by more than 30%. Some anole species disappeared from the interior forest (Guarino). Declines in number of coqui frogs (Eleutherodactylus spp) began in the 1970s. Currently, three of 16 species are extinct, and the remaining 13 species are classified in some category of endangered or threatened. Disease caused by the fungus Batrachochytrium dendrobatidis is not a factor at the elevations where study done.

Citing data from other researchers, Lister and Garcia report that numbers of insectivorous birds captured in mist nets fell 53% between 1990 and 2005.

Lister and Garcia sought to explain why there were simultaneous, long-term declines in arthropods, lizards, frogs, and birds over the past four decades in the relatively undisturbed rainforests of northeastern Puerto Rico. They concluded that climate warming has been a major factor driving reductions in arthropod abundance, and that these declines have in turn precipitated decreases in forest insectivores in a classic bottom-up cascade.

As supporting evidence, Lister and Garcia cite

(1) Declines across varied species and communities that occurred in parallel with rising temperatures.

(2) Simultaneous declines of all arthropod taxa in their own and others’ studies – pointing to an overriding environmental factor that has had ubiquitous, adverse effects on forest arthropods regardless of taxonomic affiliation, stratum occupied, or type of niche exploited.

(3) Declines in arthropod abundance that occurred despite major decreases in their predators – and, presumably, reduced predatory pressure..

Lister and Garcia note that there have been almost no significant human perturbations in the Luquillo forest since the 1930s, and that pesticide use in Puerto Rico fell nearly 80% over the past 40 years with the decrease in agricultural activity on the island. Some of the insect trend data came from studies carried out in the Luquillo Long Term Ecological Study site.

Lister and Garcia say that major weather perturbations have also had an impact. Over the 36-year time span, there have been five major hurricanes and eight severe droughts. They note that the island’s vegetation regenerated rapidly after hurricanes Hugo and Maria; insect populations regenerated rapidly after Hurricane Georges. La Niña episodes led to an immediate increase in the abundance of canopy invertebrates, whereas El Niño episodes caused declines.

Of course, some insects are under threat from loss of their primary food plants to invasive species. I note particularly the Palamedes swallowtail butterfly (Papilio palamedes), which depends on redbay and swamp bay, and an estimated 21 species of North American butterflies and moths believed to specialists or largely dependent on ash.

Palamedes swallowtail; photo by Vincent P. Lucas

In some cases, e.g., hemlock woolly adelgid and Asian longhorned beetle, neonicotenoids, specifically imidacloprid, is an essential tool to controlling a tree-killing invasive insect.

SOURCES

Dirzo, R., H.S. Young, M. Galetti, G. Ceballos, N.J. B. Isaac, B. Collen. 2014. Defaunation in the Anthropocene. Science 345, 401

Guarino, B. 2018. ‘Hyperalarming’ study shows massive insect loss. 2018. The Washington Post October 15 2018

Hallmann CA, Sorg M, Jongejans E, Siepel H, Hofland N, Schwan H, et al. 2017. More than 75 percent decline over 27 years in total flying insect biomass in protected areas. PLoS ONE 12 (10): e0185809. https://doi.org/10.1371/journal. pone.0185809

Lister, B.C. and A. Garcia. 2018. Climate-driven declines in arthropod abundance restructure a rainforest food web. Proceedings of the National Academy of Sciences. http://www.pnas.org/content/early/2018/10/09/1722477115

Morelle, R. Science Correspondent, BBC News. 2018. World wildlife ‘falls by 58% in 40 years’ https://www.bbc.com/news/science-environment-37775622

South Africa’s unique flora put at risk by polyphagous shot hole borer

The polyphagous shothole borer (PSHB) and its fungal symbiont Fusarium euwallaceae are killing trees in South Africa as well as in California.

Erythrina humeana in the Manie van der Schijff Botanical Garden, Pretoria

The pest complex’s presence was detected in August 2017 through an international sentinel tree program – the first detection of a tree pest under the program. Under the ‘sentinel plantings’ program, staff at botanical gardens and arboreta monitor their holdings – often exotic species growing outside of their natural range – and alert program partners when they detect damage caused by insects or pathogen not previously known to pose a risk. The International Plant Sentinel Network (IPSN) was launched in 2013. Botanical gardens and arboreta in South Africa joined the international effort in 2016 (Paap et al. 2918 – see list of sources at the end of this blog).

PSHB-caused tree mortality was initially detected in the KwaZulu-Natal National Botanical Gardens in Pietermaritzburg in August 2017. Affected trees were London Plane (Platanus x acerifolia) (Paap et al. 2018).

A beetle collected in 2012 in Durban, 50 km away from Pietermaritzburg, has now been determined to belong to the Euwallacea fornicatus species complex – indicating that the invasive insect and fungal species have been established in South Africa for several years (Paap et al. 2018). [Interestingly, 2012 is also the year that Dr. Akif Eskalen detected PSHB in a backyard avocado in southern California – setting off the detection, research, and slow-the-spread efforts now under way there.]

2018-10-01 PSHB - South Africa

locations of PSHB detections in South Africa; map from http://polyphagous-shot-hole-borer.co.za/

South African authorities were immediately concerned because the beetle-fungus complex attacks such a broad range of trees (species in 58 plant families). Hosts include several species native to southern Africa – including cabbage tree (Cussonia spicata), common calpurnia (Calpurnia aurea), monkey plum (Diospyros lycioides), two species of coraltree (Erythrina humeana and E. lysistemon), huilboerboon (Schotia brachypetala), honey flower (Melianthus major), two alders (Cunonia capensis and Nuxia floribunda), and red orchid bush (Bauhinia galpinii). Also at risk are several commercial crop trees such as avocado (Persea americana), macadamia nut (Macadamia integrifolia), pecan (Carya illinoinensis), peach (Prunus persica), orange (Citrus sinensis) and grapevine (Vitis vinifera) and several ornamentals, including maple, holly, wisteria, oak and Camellia (Paap et al. 2018).

South Africa is home to a highly unique flora. Indeed, the “Cape Floral Kingdom” is the smallest of the six floral regions on Earth. For more about South Africa’s botanical importance, go here or here.

Rapid spread of the beetle-fungus complex appears likely because one of the most important reproductive hosts, castor bean (Ricinus communis) is a widespread woody weed in the KwaZulu-Natal region (Paap et al. 2018).

By July 2018, it was clear that PSHB was established in several parts of the country (see map). In George — a city along the southern coast, due east of Capetown, the beetle and fungus are affecting a wide range of indigenous and exotic trees in the botanical garden and the region‚ including box elder‚ Chinese and Japanese maple‚ oak‚ plane trees‚ Kapok trees‚ paper bark acacia‚ wild plum‚ dwarf corral and common corral (Chambers 2018).

In Johannesburg, a concerned citizen tracking the pest complex’ spread thinks that the beetle-fungus combination has already infested well over 100,000 of Johannesburg’s trees and is on track to damage or kill millions more (there are an estimated 6 – 10 million trees in Johannesburg, nearly all exotic) (Weltz 2018).

SOURCES

Chambers, D. “A 2mm beetle is laying waste to George’s trees” Sunday Times. 30 May 2018 https://www.timeslive.co.za/news/sci-tech/2018-05-30-a-2mm-beetle-is-laying-waste-to-georges-trees/

Johannesburg Urban Forest Alliance. The Shot Hole Borer Beetle is destroying our Urban Forest http://www.jufa.org.za/pshb.html

Paap, T., Z.W. de Beer, D. Migliorini, W.J. Nel, M.J. Wingfield. 2018. Australasian Plant Pathology https://doi.org/10.1007/s13313-018-0545-0 https://link.springer.com/article/10.1007/s13313-018-0545-0

Weltz, A. Beetle Mania The Nasty Insect that is Killing the Trees of Johannesburg. Yale Environment 360; Published at the Yale School of Forestry and Environmental Studies. https://e360.yale.edu/features/beetle-mania-the-nasty-insect-that-is-killing-the-trees-of-johannesburg

Is EAB deregulation necessary? Is it helpful? What is at risk?

EAB risk to Oregon & Washington

USDA APHIS has formally proposed to end its regulatory program aimed at slowing the spread of the emerald ash borer (EAB) within the United States. APHIS proposes to rely on biological control to reduce impacts and – possibly – slow EAB’s spread. The proposal and accompanying “regulatory flexibility analysis” are posted here.

Public comments on this proposed change are due 19 November, 2018.

I will blog more fully about this issue in coming weeks. At present, I am on the fence regarding this change.

On the one hand, I recognize that APHIS has spent considerable effort and resources over 16 years trying to prevent spread of EAB – with less success than most would consider satisfactory. (EAB is known to be in 31 states and the District of Columbia now). While APHIS received tens of millions of dollars in emergency funding in the beginning, in recent years funding has shrunk. Over the past couple of years, APHIS has spent $6 – $7 million on EAB out of a total of about $54 million for addressing “tree and wood pests.” (See my blogs on appropriations by visiting www.cisp.us, scrolling down to “topics,” then scrolling down to “funding”). Funding has not risen to reflect the rising number of introduced pests. Presumably partly in response, APHIS has avoided initiating programs targetting additional tree-killing pests. For example, see my blogs on the shot hole borers in southern California and the velvet longhorned beetle by visiting www.cisp.us, scrolling down to “categories,” then scrolling down to “forest pest insects”. I see a strong need for new programs on new pests and money now allocated to EAB might help fund such programs.

On the other hand, APHIS says EAB currently occupies a quarter of the range of ash trees in the U.S. Abandoning slow-the-spread efforts put at risk trees occupying three quarters of the range of the genus in the country. (See APHIS’ map of infested areas here.) Additional ashes in Canada and Mexico are also at risk. Mexico is home to 13 species of ash – and the most likely pathway by which they will be put at risk to EAB is by spread from the U.S. However, APHIS makes no mention of these species’ presence nor USDA’s role in determining their fate.

I am concerned by the absence of information on several key aspects of the proposal.

APHIS makes no attempt to analyze the costs to states, municipalities, homeowners, etc. if EAB spreads to parts of the country where it is not yet established – primarily the West coast. As a result, the “economic analysis” covers only the reduced costs to entities within the quarantined areas which would be freed from requirements of compliance agreements to which they are subject under the current regulations. APHIS estimates that the more than 800 sawmills, logging/lumber producers, firewood producers, and pallet manufacturers now operating under compliance agreements would save between $9.8 M and $27.8 million annually. This appears to be a significant benefit – but it loses any meaning absent any estimate of the costs that will be absorbed by governments and private entities now outside the EAB-infested area.

ash tree killed by EAB; Ann Arbor, MI; courtesy of former mayor of Ann Arbor, MI John Hieftje

APHIS does not discuss how it would reallocate the $6 – 7 million it spends on EAB. Would it all go to EAB biocontrol? Would some be allocated to other tree-killing pests that APHIS currently ignores?

APHIS provides no analysis of the efficacy of biocontrol in controlling EAB. It does not even summarize studies that have addressed past and current releases of EAB-specific biocontrol agents. (I will report on my reading of biocontrol studies in a future blog.)

APHIS says efforts are under way to develop programs to reduce the risk of pest spread via firewood movement. APHIS does not explain what those efforts are or why they are likely to be more effective than efforts undertaken in response to recommendations from the Firewood Task Force issued in 2010.

APHIS makes no attempt to analyze environmental impacts.

champion green ash in Michigan killed by EAB

APHIS says nothing about possibly supporting efforts to breed ash trees resistant to EAB.

I welcome your input on these issues.

I will inform you of my evolving thinking, information obtained in efforts to fill in these gaps, etc. in future blogs.

Posted by Faith Campbell

Challenges to Phytosanitary Programs are International, Not Just in the U.S. How Should We Join Efforts to Defend Them?

dead ash killed by emerald ash borer; photo by Dan Herms, The Ohio State University; courtesy of Bugwood.com

I have blogged often about the funding crisis hampering APHIS’ efforts to protect our forests from damaging insects and pathogens (visit www.cisp.us, scroll down to “categories”, then scroll down to “funding”). Apparent results of this funding crisis include APHIS’ failure to adopt official programs to address several tree-killing pests (e.g., polyphagous and Kuroshio shot hole borers, goldspotted oak borer, spotted lanternfly …) and its proposal this month to end the regulatory program intended to slow the spread of the emerald ash borer (available here.) (All these tree-killing pests are described here.)

The lack of adequate resources plagues phytosanitary programs in many countries as well as at the international and regional level. As we know, the threat of introduction and spread of plant pests is growing as a result of increasing trade volume and transportation speed; increasing variety of goods being traded; and the use of containers. All countries and international bodies should be expanding efforts to address this threat, not cutting back.

Assuming you agree with me that preventing and responding to damaging plant pests is important – a task which falls within the jurisdiction of phytosanitary institutions – what more can we do to raise decision-makers’ and opinion leaders’ understanding and support? Should we join phytosanitary officials’ efforts – e.g., the International Year of Plant Health – or act separately?

How do we encourage greater engagement by such entities as professional and scientific associations, the wood products industry, state departments of agriculture, state phytosanitary officials, state forestry officials, forest landowners, environmental organizations and their funders, urban tree advocacy and support organizations. (The Entomological Society of America has engaged on invasive species although it remains unclear to me whether ESA will advocate for stronger policies and higher funding levels.)

There is one group making serious, multi-year efforts to respond. Here, I describe efforts by the International Plant Protection Convention’s (IPPC) governing body, the Commission on Phytosanitary Measures. The Commission has recognized the crisis and is attempting to reverse the situation through a coordinated strategy. I invite you to consider how we all might take part in, and support, its efforts.

Efforts of the IPPC Commission on Phytosanitary Measures

The Commission’s goal is to ensure that strong and effective phytosanitary programs “become a national and global priority that justifies and receives appropriate and sustainable support.” It seeks to achieve this by convincing decision-makers that protecting plant health from pest threats is an essential component of efforts to meet other, more broadly accepted goals, specifically the United Nations’ 2030 Sustainable Development Agenda and the Food and Agriculture Organization’s (FAO) related goals (described here).

The IPPC Commission also sees that, to succeed, it must more effectively support member countries in improving their programs to curtail pests’ spread and impacts. IPPC plans to streamline operations and integrate more closely with other FAO work in order to save money.

The following are among Commission efforts, although all are hampered by the lack of funding:

Working with member countries, the Commission has persuaded the United Nations to declare 2020 the International Year of Plant Health. (I blogged about this campaign in December 2016.
Describing links between plant health and other policy goals. The Commission is mid-way through a multi-year program. One outcome has been presentations to member states’ phytosanitary officials attending the Commission’s annual meetings, each focusing on one specific aspect. In 2018, presentations focus on links between plant health and environmental protection (presentations from April 2018 are available here). (Did you know 2018 was the year of plant health and the environment? I didn’t!) In 2016, the topic was plant health’s link to food security; in 2017, plant health and trade facilitation; in 2019, capacity development for ensuring plant health.)
Adopting a Communications Strategy. It has four broad objectives (available here).
increase global awareness of the importance of the IPPC and of the vital importance to the world of protecting plants from pests;
highlight the IPPC’s role as the sole international plant health standard setting organization aimed at improving safety of trade of plants and plant products and improving market access;
improve implementation of IPPC’s international standards (ISPMs); and
support the activities of the IPPC Resource Mobilization program.
Ramping up efforts to support implementation of its international standards. Since this 2014 decision, the Commission has conducted some pilot projects, restructured the Secretariat, and formed the Implementation and Capacity Development Committee. (I have blogged frequently about issues undermining one of those standards, the one on wood packaging material – ISPM#15. Visit www.cisp.us, scroll down to “categories”, then scroll down to “wood packaging”.)

Framework 2020-2030: the IPPC Strategic Plan

The IPPC is now finalizing its strategic plan (Framework 2020-2030), which is available here. APHIS circulated this plan in July for comment; I admit did not take the opportunity to comment because I could think of nothing to add. But now I want to link the international and domestic U.S. funding crises.

The plan describes how plant pests threaten

food production at a time rising human population and demand;
sustainable environments and ecosystem services at a time when recognition is growing of their importance for managing climate change and meeting food production goals;
free trade and associated economic development;

The plan notes that interactions between climate change and pests’ geographic ranges and impacts complicate efforts to address both threats. Also, it outlines the need for, and barriers hindering, collaborative research on plant pest. It suggests creation of an international network of diagnostic laboratories to support reliable and timely pest identifications.

The plan states several times that the IPPC is “the global international treaty for protecting plant resources (including forests, aquatic plants, non-cultivated plants and biodiversity) from plant pests …” (emphasis added). The Commission is attempting to improve its efforts to protect the environment through expanding its collaboration with the Convention on Biological Diversity, Global Environmental Facility and the Green Climate Fund. Much of the attention to environmental concerns is focused on interactions with climate change, followed by concerns about pesticide use. Indeed, the strategic plan states that “Political weight and subsequent funding for phytosanitary needs on national, regional and international level will only be available when phytosanitary issues are recognized as an important component of the climate change debate.”

The Plan describes other ways that the Commission and regional plant protection organizations might help countries overcome the major problems arising from their lack of capacity and resources. Another area of hoped-for activity is promoting collaborative research. All these proposals depend on finding funding.

However, the Strategic Plan does not reveal the extent to which its 2013 Communications Strategy has been implemented. Nor does it reveal the extent to which the effort to improve ISPM implementation has resulted in concrete progress.

Posted by Faith Campbell

New Efforts to Counter the Invasive Shot Hole Borers (ISHB) in California

willow tree killed by Kuroshio shot hole borer in Tijuana River estuary (John Boland photo)

I have blogged several times about damage caused to riparian trees in southern California by polyphagous (PSHB) and Kuroshio Shot Hole Borers (KSHB) (collectively known as invasive shot hole borers, or ISHB). The most recent blog – in July – reported the rising intensity of ISHB infestation in Orange County parks. The polyphagous shot hole borer and its associated Fusarium fungus have been found throughout Los Angeles, Orange, Riverside, San Bernardino, and Ventura Counties. The genetically distinct but morphologically indistinguishable Kuroshio shot hole borer occurs in San Diego, Orange, Santa Barbara, and San Luis Obispo Counties. New outbreaks continue to be detected – for example, one near San Juan de Capistrano.

The threat to wildland, rural, and urban hardwood forests in southern California is obvious (see the write-up here, but this is not the full extent of the peril. Preliminary research indicates that the ISHB can survive as far north as Tehama County (at the northern end of the Central Valley, south of Redding), and possibly in other parts of the country (see Greer et al., referenced below). The two beetles reproduce in more than five dozen tree and shrub species – both native and ornamental trees – that grow not just in California but across the country.

It is agreed that the ISHB do best in well-watered trees – e.g., trees in parks or other urban areas, and in riparian zones. Some fear that when the southern California drought ends, large areas of hardwood forests will become newly vulnerable. The role of water also raises the potential threat to the many species of reproductive host trees growing in the Gulf Coast and other warm and humid regions of the country.

What can people and agencies do now to counter these damaging pests? Several experts who have been working with ISHB in southern California have developed a management strategy for guiding and prioritizing actions and implementing control mechanisms targetting the beetles and their fungal symbionts that together cause the plant disease Fusarium dieback (FD). See Greer et al. Southern Calif Shot Hole Borers/Fusarium Dieback Management Strategy – full reference and link provided at the end of the blog.

This strategy attempted to advise managers on addressing outbreaks in both natural and urban landscapes at a period of rapid spread of the pests. It includes sections on establishing a leadership and coordination entity, inventory and monitoring, short-term management options, public outreach, and research to identify long-term management strategies. I don’t believe the plan’s proponents have secured funding to implement it.

Meanwhile, the California Department of Food and Agriculture and other state agencies have been officially charged by the state legislature with developing a management strategy and coordinating efforts (see another of my blogs from July). I have been told that the state agencies are working with the southern California experts in developing the state’s strategy.

The USDA Animal and Plant Health Inspection Service (APHIS) has been instructed by the Congress (in the report accompanying appropriation of funds for the Department of Agriculture) to enhance its engagement with ISHB – beyond funding provided in the past under Section 10007 of the Farm Bill. APHIS has created a Federal Task Force which is focused on three shot hole borers – in addition to the Kuroshio and polyphagous shot hole borers, also the tea shot hole borer. Several USDA agencies in addition to APHIS — Forest Service, Agriculture Research Service – as well as the U.S. Fish and Wildlife Service are developing an outline of federal agencies’ roles and responsibilities in light of state actions. The work is at an early stage.

I look forward to learning more about how each of these players plans to proceed.

Certainly, managing ISHB infestation and spread is extremely difficult. Current options in production agriculture (avocados are damaged by the pest/disease complex) and urban forests focus on the use of pesticides and removal of infested material. Then the wood and bark must be safeguarded against insects’ escape until the wood can be chipped and the insect larvae killed, for example, by using heat from solar radiation (solarization). Management options in the natural setting are limited to removal, chipping, and solarization of infested material. In any habitat, there are many logistical challenges when managing large amounts of wood.

The pest-derived difficulties have been magnified by the absence until recently of the official agencies with responsibility for managing “plant pests” (as I have complained in many blogs over the years). I hope the state and federal agencies now becoming involved will coordinate their efforts – among themselves and with the many academics, locally based agency staffs, and volunteers who have been working so hard over the past several years to counter these invaders. [To learn about these efforts, visit here.]

You have an opportunity to learn more about the shot hole borers by participating in the upcoming annual meeting of the Continental Dialogue on Non-Native Forest Insects and Diseases in November. Our meeting this year is in Irvine, California – in the infestation zone. The meeting will follow the general schedule below:

Nov 5th: Travel day with informal evening social for those arriving early
Nov 6th: Dialogue Meeting all day (8am – 5pm)
Nov 7th: Joint CFD / Arbor Day Meeting and Field Trips (including one focused on ISHB) (8am- 5pm), Networking Reception (6-8pm).

Here are the quick links of interest:

General meeting information: https://continentalforestdialogue.org/continental-dialogue-meeting-november-2018/

Dialogue-specific page on Arbor Day site:https://www.arborday.org/programs/pcf/partnering-event-continental-dialogue.cfm
Hotel information: https://www.arborday.org/programs/pcf/hotel.cfm

Some of you might also participate in the periodic workshops about the several tree-killing pests invading southern California. UC Cooperative Extension San Diego will host an Invasive Tree Pests Workshop on Friday, October 19, 2018 in Mission Beach San Diego from 9:00am-2:45pm. This workshop will focus on Goldspotted Oak Borer, Invasive Shot Hole Borers, South American Palm Weevil, and pesticide law & regulation. CEU’s have been requested from the California Department of Pesticide Regulation and Western Chapter International Society of Arboriculture. Registration is $30/person and lunch will be provided. Go to GSOB.org.

Reference

Greer, K., K. Rice, S.C. Lynch. Southern Calif Shot Hole Borers/Fusarium Dieback Management Strategy for Natural and Urban Landscapes. July 2018

http://www.southcoastsurvey.org/static_mapper/fieldguide/Southern%20California%20Shot%20Hole%20Borers-Fusarium%20Dieback%20Management%20Strategy%20for%20Natural%20and%20Urban%20Landscapes%20-%20updated%20July%202018.pdf

P.S. The polyphagous shot hole borer has been detected at numerous sites in South Africa. One of several web-based sources of information is here

Posted by Faith Campbell

APHIS’ Proposed Sudden Oak Death Rule – Ignored by Too Many Stakeholders!

P. ramorum-infected seedlings in a nursery; photo by USDA APHIS

As I blogged on 2 August, the USDA Animal and Plant Health Inspection Service (APHIS) is proposing to update its regulations intended to prevent spread of the sudden oak death (SOD) pathogen (Phytophthora ramorum) via movement of nursery stock. The proposal is to incorporate into formal regulations several changes made through temporary “Federal Orders” issued in 2014 and 2015. This might sound boring – but it was actually an important opportunity to press APHIS to correct weaknesses in its current regulatory system. Whether APHIS’ ultimate program is weak or strong will affect how well we protect our forests against every kind of pest, not just SOD.

Unfortunately, few organizations seized this opportunity. Comments were submitted by only five organizations and three individuals. The organizations were the Center for Invasive Species Prevention, California Oak Mortality Task Force, several nursery industry associations in a joint comment, and the state departments of agriculture from Florida and Pennsylvania. It is most unfortunate that the other states appear to have given up on influencing APHIS’ decisions and did not comment. (Given the long history of APHIS failure to support states trying to adopt protective regulations – as described in Chapter 3 of my report Fading Forests III, available here – perhaps this is understandable.)

The Pennsylvania Department of Agriculture (DoA) was quite critical of the proposal in its comments. It complained that APHIS is not consistent in the way it regulates various quarantine pests and the vectors on which they might be transported. Allowing shipping nurseries to submit fewer samples for testing and providing less regulatory oversight does not help protect receiving states such as Pennsylvania.

The Pennsylvania DoA noted that the Plant Protection Act has a preemption clause which prevents states from adopting regulations more stringent than those instituted by APHIS. While the law allows for exceptions if the state can demonstrate a special need, none of the five applications for an exemption pertaining to P. ramorum has been approved. (The Environmental Law Institute addressed this issue in 2011; see source at end of the blog.)

Copies of all comments can be viewed here. Their main critiques of APHIS’ proposal include:

1) APHIS should mandate sampling at all nurseries selling SOD host or associated host plant species.

While any nursery that contains or sells host or associated host plant species can become infected, APHIS does not have any system for detecting P. ramorum in such nurseries which have been infection-free for three years. This point was made by CISP and the California Oak Mortality Task force (COMTF).

1(a) Risk associated with Nurseries in the Quarantine Zone

The Florida Department of Agriculture (FDACS) objected to allowing interstate shipment of any plants – both host and non-host species – from nurseries in the quarantine zones of California and Oregon. FDACS notes that where P. ramorum is in the natural environment, it is essentially impossible to be certain that available inoculum is not in the water column or soil and thus potentially to being shipped with containerized plants.

2) Level of risk.

APHIS says that the current regulations have reduced the risk of spread of P. ramorum via the nursery trade to a low risk. APHIS cites the fact that over a nine-year period (2004 – 2013), P. ramorum was detected at a “very small percentage—usually no more than 3 percent annually” of nurseries inspected under the current program. To the contrary, I (on behalf of CISP) argue that an annual level of risk of three percent is not a low level of risk, the nursery industry’s comments accept this level of risk as “low”.

3) Inspection, Sampling, and Certification Protocols

The Pennsylvania Department of Agriculture objects that while APHIS admits the pathogen might be transmitted in media, soil, water, potted material and containers, the proposed rule does nothing to assist states in protecting themselves from pathogen transport via these vectors. Pennsylvania DoA asked APHIS to provide greater oversight so as to ensure consistency in inspection and certification procedures.

I, on behalf of CISP, said all decisions should be based on sampling and testing of water, soil, growing media, pots, and plants (leaves, stems, roots). They should not rely only on visual inspection of plants.

The Florida Department of Agriculture did not address the certification procedure directly, but objected to allowing shipment of lots of plant material determined to be free of P. ramorum from a nursery in which infected plants have been detected. FDACS pointed out that infected plants could slip through because they were asymptomatic at the time of inspection or because leaves dropped from nearby infected plants contaminated the soil.

4) Updates to the List of Hosts Should Be Comprehensive

As I noted in my previous blog, APHIS’ proposed update does not include more than a dozen species growing in the wild or in gardens in the Pacific Northwest that scientists have identified as hosts of P. ramorum; and would designate Japanese larch (Larix kaempferi) as only an “associated” host.

The California Oak Mortality Task Force raised similar issues and warned that unexplained gaps in the host list cause unnecessary confusion and undermine the scientific foundation of regulations.

Source

Porter, R.D. and N.C. Robertson. 2011. Tracking Implementation of the Special Need Request Process Under the Plant Protection Act. Environmental Law Reporter. 41.

Posted by Faith Campbell

Farm Bill Update – Please Thank Your Senators Right Away!

U.S. Senate

In May I blogged about adoption by the House of Representatives of its version of the Farm Bill, which will govern a wide range of policies for the next five years. I reported that the bill included weakened versions of a provision CISP has been seeking to establish programs to support long-term strategies to counter non-native, tree-killing insects and pathogens, e.g., biocontrol and breeding of trees resistant to pests.

I also reported that the House Farm bill contains provisions to which there is significant opposition from the larger environmental community. Several would gut some of our country’s fundamental environmental laws which have protected our health and natural resources since the early to mid-1970s. These provisions would:

Allow the U.S. Forest Service and the Interior Department’s Bureau of Land Management to decide for themselves whether an activity might “jeopardize” an endangered species (eliminating the need to consult with the U.S. Fish and Wildlife Service or National Marine Fisheries Service) (Section 8303 of the House Bill);
Allow the U.S. Forest Service and Bureau of Land Management to avoid preparing an environmental assessment under the National Environmental Policy Act (NEPA) for a long list of actions which currently must be assessed. That is, they could claim a “categorical exclusion” when taking a wide variety of “critical” actions aimed at addressing several goals. These include countering insect and disease infestations, reducing hazardous fuel loads, protecting municipal water sources, improving or enhancing critical habitat, increasing water yield, expediting salvage of dead trees following a catastrophic event, or achieving goals to maintain early successional forest. These “categorical exclusions” would apply to projects on up to 6,000 acres. (Sections 8311 – 8320); and
Require the EPA Administrator to register a pesticide if the Administrator determines that the pesticide, when used in accordance with widespread and commonly recognized practices, is not likely to jeopardize the survival of a species listed under the Endangered Species Act or to alter critical habitat. That is, the Administrator would not be required to consult with the U.S. Fish and Wildlife Service or National Marine Fisheries Service when making such determinations unlike under current law. (Section 9111).

The Senate passed its version of the Farm Bill in late June. Unfortunately, the Senate bill does not include the long-term restoration program CISP seeks. However, it doesn’t include the above attacks on environmental laws, either.

With the current Farm Bill set to expire on September 30^th, there is considerable pressure to adopt a final version soon. House and Senate staffers have been meeting to find common ground. Representatives and Senators who are on the joint Conference Committee – charged with working out the final bill – will hold their first meeting next week, on September 5^th.

In preparation for the meetings of the Conference Committee, 38 Senators have written to their two colleagues who will lead the Senate conferees. Their letter voices strong opposition to changing long-standing environmental law:

“These harmful riders, spread throughout the Forestry, Horticulture, and Miscellaneous titles of the House bill, subjected the legislation to unnecessary opposition on the House floor and now complicates [sic] the bipartisan cooperation needed to pass a final conference report.

Again, we write to express our strong opposition to gutting bedrock U.S. environmental and public health protections with provisions that threaten our air, water, lands, and wildlife.”

Senators signing the letter are:

California: Feinstein & Harris; Colorado: Bennet; Connecticut: Murphy & Blumenthal; Delaware: Carper & Coons; Florida: Nelson; Hawai`i: Hirono & Schatz; Illinois: Durbin & Duckworth; Maryland: Cardin & Van Hollen; Massachusetts: Warren & Markey; Minnesota: Klobuchar & Smith; Michigan: Peters; Nevada: Cortez Masto; New Hampshire: Shaheen & Hassan; New Jersey: Menendez & Booker; New Mexico: Udall & Heinrich; New York: Gillibrand; Oregon: Wyden & Merkley; Pennsylvania: Casey; Rhode Island: Reed & Whitehouse; Vermont: Sanders; Virginia: Warner & Kaine; Washington: Murray & Cantwell; Wisconsin: Baldwin.

If your Senators signed the letter, please email, call, or write to thank them immediately. If your Senators didn’t – please urge them to express their support for its content.

Posted by Faith Campbell