University of Florida Quincy, Florida, United States
Two experimental protocols are presented to investigate the response of the Asian Citrus Psyllid (ACP) Diaphorina citri Kuwayama (Hemiptera: Liviidae) to the red imported fire ant Solenopsis invicta Buren (Hymenoptera: Formicidae) chemical cues. The first experiment investigates whether the presence of ants in the root system of citrus affects D. citri host choice, by placing two citrus plants (a control and a treatment) in an arena. The treatment constitutes a citrus plant with ant-infested soil, while the control is an equivalent which is free of ants. A plastic vial containing 20 - 25 Asian citrus psyllid adults is placed at an equal distance from each plant after which host choice is recorded. The second protocol examines whether the presence of ant trails on the shoot system of citrus affects D. citri host choice. In this experiment, ant trails are collected in glass tubes and are extracted with hexane. Then, the trail solution is mechanically applied on the leaves of the respective specimens. Similar to the previous experiment, ACP adults are released to choose between treatment and control in a caged setting, and their choice is recorded. The overall hypothesis of these experiments is that D. citri will be attracted to citrus that is exposed or was exposed to S. invicta because of the mutualistic relationship that exists between the two species in natural settings.
