Responses of two parasitoid wasps to nectar odors as a function of experience

Abstract

AbstractAdult parasitoid wasps can learn to recognize specific resource‐based cues, making them adept at locating essential resources within their native habitats. However, relatively little is known about their ability to recognize the odors emitted by flowers and extra‐floral nectar glands. A novel test arena mimicking the distribution of nectaries within an umbelliferous inflorescence was developed to measure and compare the responses of two eulophid wasps, Edovum puttleri and Pediobius foveolatus, to nectar‐based odors. Although both parasitoid species were able to associate nectar location with the odors emitted by both real nectaries (dill flowers and snap bean stipules) and artificial nectars (1 M sucrose solution scented with banana or lemon food flavoring), the responses of inexperienced wasps to nectary odors differed. While inexperienced E. puttleri displayed little attraction to the odor of either dill flowers or snap bean stipules, inexperienced P. foveolatus displayed a strong attraction to odors of both types of nectaries. However, once it had experienced foraging on either dill or snap bean nectar, E. puttleri responded to those nectary odors as strongly as did P. foveolatus. The responsiveness of both wasp species to the odor of artificial nectar greatly increased after they foraged on sugar solution scented with either banana or lemon odor. That parasitoid wasp species can differ in their ability to recognize food‐based cues is of fundamental and applied importance.