Association of two Bactericera species (Hemiptera: Triozidae) with native Lycium spp. (Solanales: Solanaceae) in the potato growing regions of the Rio Grande Valley of Texas

Authors: Cooper, William - Rodney; ESPARZA-DIAZ, GABRIELLE - Amer Stem Incorporated; WILDUNG, MARK - Washington State University; Horton, David; BADILLO-VARGAS, ISMAEL - Texas A&M University; HALBERT, SUSAN - Florida Department Of Agriculture And Consumer Services

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2022
Publication Date: 12/31/2022
Citation: Cooper, W.R., Esparza-Diaz, G., Wildung, M.R., Horton, D.R., Badillo-Vargas, I.E., Halbert, S.E. 2022. Association of two Bactericera species (Hemiptera: Triozidae) with native Lycium spp. (Solanales: Solanaceae) in the potato growing regions of the Rio Grande Valley of Texas. Environmental Entomology. 52(1):98-107. https://doi.org/10.1093/ee/nvac109.
DOI: https://doi.org/10.1093/ee/nvac109

Interpretive Summary: Potato psyllid is an important pest of potato as the vector of the zebra chip pathogen. Management of the potato psyllid and zebra chip is challenging because we do not yet know the non-crop sources of infective psyllids arriving in potato fields in many potato growing regions. Species of Lycium are known to be an important source of potato psyllids in certain potato growing regions where zebra chip is an occasional problem but is it still unknown whether Lycium are important non-crop sources of psyllids in the Rio Grande Valley of Texas were zebra chip is a consistent challenge to growers. Researchers at the USDA-ARS in Wapato, WA and Texas A&M University showed that Lycium berlandieri and Lycium carolinianum are likely non-crop sources of potato psyllids arriving in potato fields of South Texas and that L. carolinianum is a potential source of psyllids carrying the zebra chip pathogen. The researchers also routinely collected another psyllid, Bactericera dorsalis, from both Lycium species, and found that the psyllid is also capable of vectoring the zebra chip pathogen to Lycium but not to potato. Results of this study could improve areawide management of potato psyllid and the zebra chip pathogen.

Technical Abstract: Bactericera cockerelli (Šulc) (Hemiptera: Triozidae) is a vector of “Candidatus Liberibacter solanacearum” (Lso), the pathogen that causes potato zebra chip disease. Zebra chip incidence varies regionally, perhaps because of geographic differences in species of non-crop hosts available to the vector and in susceptibility of those hosts to Lso. Native and introduced species of Lycium (Solanales: Solanaceae) are important non-crop hosts of B. cockerelli in some regions of North America. Susceptibility of native species of Lycium to Lso is uncertain. We investigated the use of two native species of Lycium by B. cockerelli in South Texas and tested whether these species are susceptible to Lso. Bactericera cockerelli adults and nymphs were collected frequently from L. berlandieri Dunal and L. carolinianum Walter. Greenhouse assays confirmed that B. cockerelli develops on both species and showed that Lso infects L. carolinianum. Molecular gut content analysis provided evidence that B. cockerelli adults disperse between potato and Lycium. Together these results demonstrate that L. berlandieri and L. carolinianum are likely non-crop sources of potato-colonizing B. cockerelli in South Texas and that L. carolinianum is a potential source of Lso-infected psyllids. We also routinely collected the congeneric psyllid, Bactericera dorsalis (Crawford), from both Lycium species. These records are the first for this psyllid in Texas. Bactericera dorsalis completed development on both native Lycium species, albeit with high rates of mortality on L. berlandieri. B. dorsalis acquired and transmitted Lso on L. carolinianum under greenhouse conditions but did not transmit Lso to potato. These results document a previously unknown vector of Lso.