UV reflective properties of magnesium oxide increase the attraction and probing behavior by Asian citrus psyllids (Hemiptera: Liviidae)

Authors: GEORGE, JUSTIN - University Of Florida; PARIS, THOMSON - University Of Florida; Allan, Sandra - Sandy; Lapointe, Stephen; STELINSKI, STEPHEN - University Of Florida

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/6/2020
Publication Date: 2/5/2020
Citation: George, J., Paris, T.M., Allan, S.A., Lapointe, S.L., Stelinski, S.L. 2020. UV reflective properties of magnesium oxide increase the attraction and probing behavior by Asian citrus psyllids (Hemiptera: Liviidae). Scientific Reports. 10:1890. https://doi.org/10.1038/s41598-020-58593-4.
DOI: https://doi.org/10.1038/s41598-020-58593-4

Interpretive Summary: Asian citrus psyllid (Diaphorina citri) vectors the bacterium Candidatus Liberibacter asiaticus, the causal pathogen of citrus greening disease that is devastating citrus industries worldwide. Suppressing psyllid populations is crucial to prevent disease spread and damage. An attract-and-kill trap based on psyllid behavior would fill a niche for monitoring and control of populations. In this study, scientists at USDA/ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida, along with scientists at USDA/ARS, Fort Pierce, Florida and the University of Florida evaluated the impact of adding UV reflecting pigments to visual attractants for the Asian citrus psyllid. Addition of two UV-reflecting pigments increased UV reflectance from traps resulting in greater attraction to traps and greater probing on trap surfaces. These results indicate that both UV and visible colors (yellow, lime green) are important for attraction of psyllids. This information can ultimately improve attraction and efficiency of an attract-and-kill device which can serve as an important tool in an integrated management system for the Asian citrus psyllid.

Technical Abstract: Asian citrus psyllid (Diaphorina citri) vectors the bacterium Candidatus Liberibacter asiaticus, the causal pathogen of citrus greening disease that is devastating citrus industries worldwide. Suppressing psyllid populations is crucial to prevent disease spread and damage. An attract-and-kill trap based on psyllid behavior would fill a niche for monitoring and control of populations. To optimize visual attraction of psyllids, the ultraviolet (UV) reflective properties of magnesium oxide (MgO) and/or barium sulfate (BaSO4) were assessed for potential application to a trap surface. Under low UV, high UV and natural sunlight conditions, the reflectance, attraction, and probing behaviors of psyllids were evaluated to white and yellow SPLAT containing magnesium oxide or barium sulfate. Additionally, magnesium oxide added to yellow sticky traps enhanced visual response of D. citri. Probing assays demonstrated that magnesium oxide alone or a mixture, increased the UV reflectance, attraction and probing on the SPLAT. The combination of a phagostimulant blend with UV-reflecting magnesium oxide increased attraction to yellow SPLAT. Results demonstrated that psyllids employ a both short (UV) and long wavelengths (yellow) for host location, and that these inert compounds can increase UV reflectance and ultimately improve attraction and efficiency of an attract-and-kill device.