Recognition of Novel Volatile Cues by the Nymphs of the Glassy-winged Sharpshooter, Homalodisca vitripennis (Cicadellidae)

Abstract

Nymphs of Homalodisca vitripennis are strict xylophages and frequently switch host-plants to obtain a balanced level of nutrients at appropriate tension levels. Associative learning of odors and other semiochemicals may enhance the nymphs’ ability to recognize and locate potential host-plants. We examined whether nymphs could learn to associate a novel olfactory stimulus (vanilla) with a host-plant. Nymphs fed on cowpea plants treated systemically with vanilla extract or on untreated plants. Subsequently, their responses to a pale green target were measured in the presence or absence of vanilla odor. Nymphs were not innately attracted to pale green, and exposure to vanilla odor did not decrease a stereotypical scanning behavior. However, when presented with vanilla odor, significantly more conditioned nymphs selected the target than did control nymphs.