Evidence of Olfactory and Visual Learning in The Asian Citrus Psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae)

Investigation of the mechanisms underlying learning and memory can be achieved through research on neurobiologically simplified invertebrate species. As such, insects have been used for decades as ideal models of olfactory learning. The current study aimed to investigate the mechanisms of chemosensory attraction in an invasive insect, Diaphorina citri, the Asian citrus psyllid (ACP), through manipulation of olfactory stimuli. After classical conditioning to a non-innate cue (vanilla extract), psyllids displayed enhanced feeding behavior. There was, however, an inverse relationship between olfactory “noise” and feeding behavior. Preliminary data suggests ACP may also be visual learners, as evidenced by trials attempting to condition ACP to the color blue. The data indicate that while learning is possible in ACP, it is easily disrupted. As a result, innate response to host plant stimuli in oligophagous, selective feeding insects may represent the most adaptive means of locating resources.