title: Associative learning for danger avoidance nullifies innate positive chemotaxis to host olfactory stimuli in a parasitic wasp.
abstract: Animals rely on associative learning for a wide range of purposes, including danger avoidance. This has been demonstrated for several insects, including cockroaches, mosquitoes, drosophilid flies, paper wasps, stingless bees, bumblebees and honeybees, but less is known for parasitic wasps. We tested the ability of Psyttalia concolor (Hymenoptera: Braconidae) females to associate different dosages of two innately attractive host-induced plant volatiles (HIPVs), ethyl octanoate and decanal, with danger (electric shocks). We conducted an associative treatment involving odours and shocks and two non-associative controls involving shocks but not odours and odours but not shocks. In shock-only and odour-only trained wasps, females preferred on HIPV-treated than on blank discs. In associative-trained wasps, however, P. concolor's innate positive chemotaxis for HIPVs was nullified (lowest HIPV dosage tested) or reversed (highest HIPV dosage tested). This is the first report of associative learning of olfactory cues for danger avoidance in parasitic wasps, showing that the effects of learning can override innate positive chemotaxes.
authors.affiliation: Insect Behaviour Group, Department of Agriculture, Food and Environment, University of Pisa, via del Borghetto 80, 56124, Pisa, Italy, g.benelli@sssup.it.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Benelli
authors.forename: Cesare
authors.initials: C
authors.lastname: Stefanini
authors.forename: Giulia
authors.initials: G
authors.lastname: Giunti
authors.forename: Serena
authors.initials: S
authors.lastname: Geri
authors.forename: Russell H
authors.initials: RH
authors.lastname: Messing
authors.forename: Angelo
authors.initials: A
authors.lastname: Canale
mesh_terms: D000818:Animals; D001362:Avoidance Learning / Q000502:physiology*; D002633:Chemotaxis / Q000502:physiology*; D003463:Cues; D004560:Electricity; D005260:Female; D006790:Host-Parasite Interactions / Q000502:physiology*; D009812:Odorants; D010944:Plants / Q000737:chemistry; D014863:Wasps / Q000502:physiology*