The Palearctic psyllid Agonoscena succincta (Heeger): Detection in North America and a global look at psyllid and host spread (Hemiptera: Psylloidea: Aphalaridae)

Authors: Horton, David; Lewis, Tamera; CERVANTES, EVA - Heritage University; Angelella, Gina; OHLER, BONNIE - Washington State University; Cooper, William; DYER, JARED - Cornell University; GILREIN, DANIEL - Cornell University; MOORE, MATTHEW - Florida Department Of Agriculture And Consumer Services; HALBERT, SUSAN - Florida Department Of Agriculture And Consumer Services

Submitted to: Proceedings of the Entomological Society of Washington
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/20/2025
Publication Date: 3/19/2026
Citation: Horton, D.R., Lewis, T.M., Cervantes, E., Angelella, G.M., Ohler, B.J., Cooper, W.R., Dyer, J., Gilrein, D.O., Moore, M.R., Halbert, S.E. 2026. The Palearctic psyllid Agonoscena succincta (Heeger): Detection in North America and a global look at psyllid and host spread (Hemiptera: Psylloidea: Aphalaridae). Proceedings of the Entomological Society of Washington. 128(1):1-18. https://doi.org/10.4289/0013-8797.128.1.1.
DOI: https://doi.org/10.4289/0013-8797.128.1.1

Interpretive Summary: Agonoscena succincta is a small psyllid of Mediterranean origin now present as an introduced species in several European countries, North Africa, and South America. USDA researchers in Wapato, WA, in collaboration with University and State Researchers in Washington, New York, and Florida show that the psyllid also is now present in North America. Infestations were discovered in eastern North America and in the northwestern U.S. Psyllids were collected from its host plant, common rue. Morphology, global distribution, and biology of the psyllid are briefly described. The importance of the host plant in assisting global and local spread of the psyllid is explored in some depth. The rue host is native to the Mediterranean Basin. Human-assisted spread of rue has led to entry of the plant into geographic regions well outside of its ancestral range. We examine how geographic spread of rue has led to range expansion of A. succincta, and conclude that new records will continue to accumulate as the psyllid spreads and as new infestations are discovered.

Technical Abstract: Agonoscena succincta (Heeger, 1856) (Hemiptera: Psylloidea: Aphalaridae) is a small psyllid of Mediterranean origin now present as an adventive species in several European countries, North Africa, and South America. The current study shows that A. succincta also is now established in North America. Infestations were discovered in eastern North America and in the northwestern U.S. Psyllids were collected from common rue, Ruta graveolens (Sapindales: Rutaceae). Morphology, global distribution, and biology of A. succincta are briefly described. The importance of the host plant in assisting global and local spread of the psyllid is explored in some depth. Known host plants of A. succincta are limited to R. graveolens and fringed rue, Ruta chalepensis. Both plants are native to the Mediterranean Basin. As with many other adventive psyllid species, establishment of A. succincta outside of its region of origin requires presence of the natal host plant. Human-assisted spread of R. graveolens and R. chalepensis began centuries or millennia ago for medicinal, ceremonial, religious, and culinary purposes. These traditional uses have led to the assimilation of rue into many different cultures and to the entry of rue centuries ago into geographic regions well outside of the ancestral range of the plants. Regional spread of Ruta continues today for some of these same ethnobotanical purposes, but also for use as a landscape or container plant and as a target for pharmacological research. We examine how geographic spread of rue has led to range expansion of A. succincta, and conclude that new records will continue to accumulate as the psyllid spreads and as previously unknown infestations are discovered.