Bactericera maculipennis (Hemiptera: Triozidae) is a vector of “Candidatus Liberibacter solanacearum” to species within the Convolvulaceae (Solanales)

Authors: Cooper, William; OHLER, BONNIE - Washington State University; WENNINGER, ERIK - University Of Idaho; DAHAN, JENNIFER - University Of Idaho; KARASEV, ALEXANDER - University Of Idaho; JENSEN, ANDY - California Academy Of Sciences; WOHLEB, CARRIE - Washington State University; WATERS, TIMOTHY - Washington State University; KENNEY, JAIMIE - University Of California, Riverside; MAUCK, KERRY - University Of California, Riverside; Horton, David

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/22/2025
Publication Date: 9/22/2025
Citation: Cooper, W.R., Ohler, B., Wenninger, E.J., Dahan, J., Karasev, A.V., Jensen, A.S., Wohleb, C., Waters, T., Kenney, J.R., Mauck, K.E., Horton, D.R. 2025. Bactericera maculipennis (Hemiptera: Triozidae) is a vector of “Candidatus Liberibacter solanacearum” to species within the Convolvulaceae (Solanales). Environmental Entomology. https://doi.org/10.1093/ee/nvaf088.
DOI: https://doi.org/10.1093/ee/nvaf088

Interpretive Summary: Liberibacter solanacearum (Lso) is a plant pathogen spread by potato psyllid that causes potato zebra chip disease. Although potato psyllid is the only known insect vector of Lso in potato, up to 50% of a related psyllid called bindweed psyllid carries Lso in Washington State. Researchers have yet to detect Lso in the plant host of bindweed psyllid, field bindweed, so it is not clear how the pathogen persists in psyllid populations. Researchers at the USDA-ARS in Wapato, WA in collaboration with university scientists surveyed plants for bindweed psyllid and Lso. They discovered that Lso is undetectable in the leaves of field bindweed but is readily detectable in the stems of these plants. They report a high rate of Lso infection in populations of bindweed psyllid and potato psyllid collected from field bindweed when compared with psyllids collected from other plants. Fortunately, potato psyllid occurred in very low numbers on field bindweed, and only during autumn months after potato harvest. Bindweed psyllid transmitted Lso to field bindweed but does not transmit Lso to potato plants. Results suggest that field bindweed is a potential reservoir for Lso in the Pacific Northwest, but do not suggest that bindweed psyllid is a direct threat to potato production or that large numbers of potato psyllid arrive in potato from field bindweed.

Technical Abstract: Bactericera maculipennis (Crawford) and Bactericera cockerelli (Šulc) (Hemiptera: Triozidae) share hosts within the Solanaceae and Convolvulaceae (Solanales) and are both associated with “Candidatus Liberibacter solanacearum” (Lso). Lso, transmitted by B. cockerelli, causes diseases in solanaceous crops including zebra chip disease of potato. Up to 50% of B. maculipennis adults also harbor Lso, but transmission of Lso to plants by this psyllid has not yet been confirmed. The only documented field host of B. maculipennis in the Pacific Northwest is Convolvulus arvensis L. (Convolvulaceae) but diagnostic methods fail to detect Lso in leaves of this plant. It is therefore unclear how Lso persists within B. maculipennis populations. We surveyed species of Convolvulaceae and Solanaceae for B. maculipennis and report a widespread association between B. maculipennis and Lso throughout the western United States. Diagnostic polymerase chain reaction failed to detect Lso from leaves of C. arvensis yet readily detected Lso from stems where B. maculipennis nymphs tend to feed. Bactericera maculipennis transmitted Lso to species of Convolvulaceae in greenhouse experiments confirming vector competency. We report high rates of Lso infection in populations of both B. maculipennis and B. cockerelli occurring on C. arvensis, but occurrence of B. cockerelli on C. arvensis was limited to autumn months only and with very low populations. Results suggest C. arvensis is a non-crop reservoir of Lso, but do not suggest that B. maculipennis is a direct threat to solanaceous crops or that C. arvensis is a major source of Lso-infected B. cockerelli colonizing potato fields.