The U.S. Geological Survey (USGS) has published an updated register of introduced species in the United States. The master list contains 14,700 records, of which 12,571 are unique scientific names. The database is divided into three sub-lists: Alaska, with 545 records; Hawai`i, with 5,628 records; and conterminous (lower 48) United States, with 8,527 records.
The project tracks all introduced (non-native) species that become established, because they might eventually become invasive. The list includes all taxa that are non-native everywhere in the locality (Alaska, Hawai`i, or 48 conterminous states) and established (reproducing) anywhere in that locality.
Each record has information on taxonomy, a vernacular name, establishment means (e.g., unintentionally, or assisted colonization), degree of establishment (established, invasive, or widespread invasive), hybrid status, pathway of introduction (if known), habitat (if known), whether a biocontrol species, dates of introduction (if known; currently 47% of the records), associated taxa (where applicable), native and introduced distributions (when known), and citations for the authoritative source(s) from which this information is drawn.
The 2022 version is more complete re: plant pathogens than earlier iterations; I thank the hard-working compilers for their efforts!
Hawai`i
Among the non-native species listed as being in Hawai`i are 3,603 Arthropods, including the following about which I have blogged:
- three Euwallaceae,
- Erythrina gall wasp (Quadrastichus erythrinae),
- Klambothrips myopori,
- eight species of mosquito in the Hawaiian islands, including the Culex and Aedes species that vector the diseases that have caused extinction of numerous endemic bird species on the Islands.
The list also includes 25 fungi, among them the two species of Ceratocystis that cause rapid ʻōhiʻa death; DMF & blog 270 and the ʻōhiʻa or myrtle rust, Austropuccinia psidii.
Also listed are 95 mollusk species and 20 earthworm species. I wonder who is studying the worms’ impacts? I doubt any is native to the Islands.
The Hawaiian list contains 1,557 non-native plant species. Families with largest representation are Poaceae (grass) – 223 species; Fabaceae (beans) – 156 species; and Asteraceae – 116 species. About a third of the plant species – 529 species – are designated as “widespread invaders”. This number is fifteen times higher than the numbers in lists maintained by either the Hawaiian Ecosystems At Risk project (106 species) [HEAR unfortunately had to shut down a decade ago due to lack of funds]; or Hawaiian Invasive Species Council (80 species). Furthermore, some of the species listed by HEAR and HISC are not yet widespread; the lists are intended to facilitate rapid responses to new detections. We always knew Hawai`i was being overrun by invasive species!
Among the 529 most “widespread invaders” are the following from the most introduced families:
- Poaceae – Agrostis stolonifera, 6 Cenchrus spp, 2 Cortaderia spp, 3 Eragrostis,8 Paspalum, 4 Setaria spp, 2 Urochloa (Poacae)
- Fabaceae – 3 Acacia, 2 Prosopis
Other families have fewer introduced species overall, but notable numbers of the most widespread invaders:
- Euphorbiaceae – 8 spp. of Euphorbia
- Cyperaceae – 6 spp. of Cyperus
- Myrtaceae – Melaleuca quinquenervia, 2 Psidium, Rhodomyrtus tomentosa rose myrtle, 3 Syzygium [rose myrtle has been hard-hit by the introduced myrtle rust fungus]
- Zingiberaceae – 3spp. Hedychium (ginger)
- Anacardiaceae — Schinus molle (Peruvian peppertree); USGS considers congeneric S. terebinthifolia to be somewhat less widespread.
Plus many plant taxa familiar to those of us on the continent: English ivy, privet, castor bean, butterfly bush, Ipomoea vines … and in more limited regions, Japanese climbing fern Lygodium japonicum.
I learned something alarming from the species profiles posted on the HISC website: the Hawaiʻi Division of Forestry and Wildlife and Hawaiʻi Department of Agriculture are considering introduction of a species of thrips, Pseudophilothrips ichini, as a biocontrol agent targetting S. terebinthifolia. I learned in early 2019, when preparing comments on Florida’s proposed release of this thrips, that Pseudophilothrips ichini can reproduce in low numbers on several non-target plant species, including two native Hawaiian plants that play important roles in revegetating disturbed areas. These are Hawaiian sumac Rhus sandwicensis and Dodonea viscosa. The latter in particular is being propagated and outplanted in large numbers to restore upland and dryland native ecosystems. While the environmental assessment prepared by the USDA Animal and Plant Service says the thrips causes minimal damage to D. viscosa, I am concerned because of the plant species’ ecological importance. Of course, the two Schinus species are very damaging invasive species in Hawai`i … but I think introducing this thrips is too risky. [To obtain a copy of CISP’s comments, put a request in comments section. Be sure to include your email address in your comment; the section algorithm does not include email addresses (how inconvenient!).]
Continental (lower 48) states
Among the 8,500 species listed in the USGS Register for the 48 continental states are 4,369 animals, among them 3,800 arthropods; 3,999 plants; and just 89 fungi. Among the arthropods, there are 1,045 beetles and 308 lepidopterans. The beetles listed include 12 Agrilus (the genus which includes emerald ash borer and goldspotted oak borer.) It does not include the elm zig-zag sawfly USGS staff have not found any publications documenting its U.S. occurrences. Among the microbes are six Phytophthora (P. cinnamomi, P. lateralis, P. pseudocryptogea, P. quercina, P. ramorum, P. tentaculata). Profiles of several of these species are posted at www.dontmovefirewood.org; click on “invasive species”, then scroll using either Latin or common name.
Citation:
Simpson, Annie, Pam Fuller, Kevin Faccenda, Neal Evenhuis, Janis Matsunaga, and Matt Bowser, 2022, United States Register of Introduced and Invasive Species (US-RIIS) (ver. 2.0, November 2022): U.S. Geological Survey data release, https://doi.org/10.5066/P9KFFTOD
United States Register of Introduced and Invasive Species; US-RIIS ver. 2.0, 2022
If you would like to contribute to future versions of the US-RIIS, please email the project leaders at us-riis@usgs.gov.
Posted by Faith Campbell
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For a detailed discussion of the policies and practices that have allowed these pests to enter and spread – and that do not promote effective restoration strategies – review the Fading Forests report at http://treeimprovement.utk.edu/FadingForests.htm
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