Learning, odour preference and flower foraging in moths

Abstract

Floral volatiles play a major role in plant-insect communication. We examined the influence of two volatiles, phenylacetaldehyde and α-pinene, on the innate and learnt foraging behaviour of the moth Helicoverpa armigera. In dual-choice wind tunnel tests, adult moths flew upwind towards both volatiles, with a preference for phenylacetaldehyde. When exposure to either of these volatiles was paired with a feeding stimulus (sucrose), all moths preferred the learnt odour in the preference test. This change in preference was not seen when moths were exposed to the odour without a feeding stimulus. The learnt preference for the odour was reduced when moths were left unfed for 24·h before the preference test.We tested whether moths could discriminate between flowers that differed in a single volatile component. Moths were trained to feed on flowers that were odour-enhanced using either phenylacetaldehyde or α-pinene. Choice tests were then carried out in an outdoor flight cage, using flowers enhanced with either volatile. Moths showed a significant preference for the flower type on which they were trained. Moths that were conditioned on flowers that were not odour-enhanced showed no preference for either of the odour-enhanced flower types. The results imply that moths may be discriminating among odour profiles of individual flowers from the same species. We discuss this behaviour within the context of nectar foraging in moths and odour signalling by flowering plants.

Geographical matching of volatile signals and pollinator olfactory responses in a cycad brood-site mutualism

“…The cognitive basis of pollinator attraction to floral volatiles can be innate [56] or learned [57]. The sensory preferences of insects involved in highly specialized brood-site mutualisms are expected to be innate [58,59], and may arise from mutual adaptations of the pollinators' sensory systems and floral signals. This contention is supported by the differences in electrophysiological responses to particular compounds that we observed for beetles from different populations ( figure 1d-f ).…”

Cognition in Invertebrates

“…In the moth Helicoverpa armigera, for instance, Cunningham et al (2004) have shown that experience-deprived adult moths raised in isolation exhibit innate preferences for phenylacetaldehyde when tested in dual-choice wind tunnel tests. Again, this preference changes rapidly if a nonpreferred volatile substance is paired with a feeding stimulus (sucrose solution).…”

Pollinator and Herbivore Attraction to Cucurbita Floral Volatiles

“…Plant volatiles can attract pollinators, provide learning cues for foraging insects, serve as herbivore repellants or attractants, or attract natural enemies of herbivores (De Moraes et al 1998;Pichersky and Gershenzon 2002;Cunningham et al 2004;Ashman et al 2005;Huber et al 2005). Despite the many ways that scent influences interactions between plants and insects, we know relatively little about how herbivores and pollinators respond to the same scent volatiles.…”