Innate Host Habitat Preference in the Parasitoid Diachasmimorpha longicaudata: Functional Significance and Modifications through Learning

DIEGO F SEGURA; NUSSENBAUM AL; DEVESCOVI F; BACHMANN GUILLERMO; MARIANA M. VISCARRET; SERGIO M. OVRUSKI; CLADERA, J

PLOS ONE

PUBLIC LIBRARY SCIENCE

Lugar: San Francisco; Año: 2016

1932-6203

Parasitoids searching for polyphagous herbivores can find their hosts in a variety of habitats.Under this scenario, chemical cues from the host habitat (not related to the host) representpoor indicators of host location. Hence, it is unlikely that naïve females show a strongresponse to host habitat cues, which would become important only if the parasitoids learn toassociate such cues to the host presence. This concept does not consider that habitats canvary in profitability or host nutritional quality, which according to the optimal foraging theoryand the preference-performance hypothesis (respectively) could shape the way in whichparasitoids make use of chemical cues from the host habitat. We assessed innate preferencein the fruit fly parasitoid Diachasmimorpha longicaudata among chemical cues fromfour host habitats (apple, fig, orange and peach) using a Y-tube olfactometer. Contrary towhat was predicted, we found a hierarchic pattern of preference. The parasitism rate realizedon these fruit species and the weight of the host correlates positively, to some extent,with the preference pattern, whereas preference did not correlate with survival and fecundityof the progeny. As expected for a parasitoid foraging for generalist hosts, habitat preferencechanged markedly depending on their previous experience and the abundance of hosts.These findings suggest that the pattern of preference for host habitats is attributable to differencesin encounter rate and host quality. Host habitat preference seems to be, however,quite plastic and easily modified according to the information obtained during foraging.