Exotic psyllids and exotic hosts: accumulation of non-native Psylloidea in North America (Hemiptera)

Authors: Horton, David; MILICZKY, GENE - Washington State University; WATERS, TIM - Washington State University; BURCKHARDT, DANIEL - Naturhistorisches Museum Basel; HALBERT, SUSAN - Florida Department Of Agriculture And Consumer Services

Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/18/2021
Publication Date: 4/28/2021
Citation: Horton, D.R., Miliczky, G., Waters, T., Burckhardt, D., Halbert, S. 2021. Exotic psyllids and exotic hosts: accumulation of non-native Psylloidea in North America (Hemiptera). Annals of the Entomological Society of America. 114(4):425-447. https://doi.org/10.1093/aesa/saab014.
DOI: https://doi.org/10.1093/aesa/saab014

Interpretive Summary: Colonization of North America by non-native psyllids has led to economic and ecological damage as psyllids attack agricultural hosts, ornamental plants, and landscape plants. Biological and geographical factors which may predispose a given psyllid species for successful colonization of North America are unknown, which hinders efforts to develop a list of psyllid traits which predict invasiveness. Researchers at USDA-ARS Wapato in Washington, in collaboration with scientists from Washington State University, the Naturhistorisches Museum of Basel Switzerland, and the Florida Department of Agriculture and Consumer Services conducted an extensive historical survey of the literature documenting arrival, host plant use, geographic origin, and life history traits of non-native psyllid species in North America. The literature survey showed that at least 46 species of psyllids are introductions in North America, and that arrival dates back to the early 1800s by a European species that feeds on pear trees. The synthesis led to the discovery that the best predictor of invasiveness was whether the host plant of the psyllid in the insect’s native region had also been introduced into North America. Other traits predicting invasiveness include geographic origin, shown by an overrepresentation in psyllids arriving from Australia or South America. Results of this extensive survey allow us to better predict what psyllid traits predispose a species for invasiveness, which in turn can be used to guide biosecurity and quarantine efforts

Technical Abstract: The Psylloidea (Hemiptera) comprise ~3800 species of small sap-feeding insects known as psyllids or jumping plant-lice. We summarize species composition of the non-native psyllid fauna in North America and review detection records, current distributions, host use, life histories, and geographical sources. Forty-six species are considered to be non-native accounting for ~10% of the known North American psyllid fauna. The family Psyllidae is overrepresented in the pool of exotics (52% of exotic species) relative to global psyllid diversity while Triozidae (at 11% of exotic species) is underrepresented. Records of initial detection range from the 1832 detection of a European pear psyllid to the 2016 detection of a Ficus specialist from Asia. Many species exhibit discontinuous distributions in North America likely caused by multiple introductions. Adventive psyllids develop almost exclusively on trees and shrubs. The factor most correlated with introduction is presence of hosts from the psyllid’s native region. Virtually all host plants in North America have been imported intentionally for human-related use, with initial importation beginning in the 1500s and 1600s. Arrival of host plants in North America often preceded psyllid detection by decades or centuries. There has been almost no spillover by psyllids onto native plant species reflecting the narrow host range of Psylloidea. A glaring exception is the recent damaging colonization of a native Fraxinus closely related to the psyllid’s European Fraxinus host. Biological and geographical traits correlated with arrival and establishment of non-native species have shifted through time. Temperate Europe was the source of the earliest arriving species, with initial detection records primarily in New England and eastern Canada. In contrast, recent arrivals are mostly Myrtincludeaceae- and Fabaceae-feeding species from the Neotropics or Australia, with detection records limited mostly to Florida or California. Early-arriving, temperate zone species exhibit a formal winter diapause while recent arrivals from the Neotropics and Australia reproduce more-or-less continuously