Recognition of foreign oviposition marking pheromones is context dependent and determined by preimaginal conditioning

Authors: STELINSKI, LUKASZ - University Of Florida; Zhang, Aijun; ONAGBOLA, EBENEZER O. - University Of Florida; MEYER, WENDY - University Of Florida

Submitted to: Communicative and Integrative Biology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/17/2009
Publication Date: 10/15/2009
Citation: Stelinski, L., Zhang, A., Onagbola, E., Meyer, W. 2009. Recognition of foreign oviposition marking pheromones is context dependent and determined by preimaginal conditioning. Communicative and Integrative Biology. 2(5):391-393.

Interpretive Summary: Apple maggot is a major pest of cultivated apples in the northeastern United States and southeastern Canada. We know there are parasitic wasps that will infect the apple maggot and can be used to control it. However, the maggot seems to recognize when wasp eggs are present on an apple, and the maggot will not lay its own eggs there. We wanted to know how the maggot detects and avoids the control parasite. Apple maggots will also attach to hawthorn as a second host, but they do not seem to recognize when the parasite eggs are present on hawthorn. What we learned was that if the apple maggots were grown on apple, they would learn to sense the parasite’s chemical trace on the apple, but not on hawthorn. If they were grown on hawthorn, they would learn to sense the parasite chemicals on hawthorn, but not on apple. This is the first reported instance of an insect learning to recognize a predator’s chemicals because of where it grows. Scientists will use this knowledge to develop better controls for apple orchard management to reduce apple maggot damage.

Technical Abstract: Many insects deposit marking pheromones following egg-laying that signal an occupied and thus sub-optimal resource. Herbivorous insects mark host fruit or other vegetative plant parts after depositing eggs, while insect parasitoids deposit such pheromones directly on the cuticle of a particular life stage of their prey. These oviposition marking pheromones (OMPs) are then recognized by conspecifics, who avoid subsequent egg-laying in the previously utilized and unsuitable host. Since many host resources are capable of supporting a limited number of offspring, these pheromones function to decrease competition among the brood, which increases survival rate of the subsequent generation. In rare instances, distinct species of phytophagous and parasitic insects will inspect the same substrate following egg-laying.1 Recently, Stelinski et al.1 have demonstrated that in such instances, the herbivore is able to learn to recognize its predator’s OMP and utilize it to its advantage by avoiding oviposition into unsuitable host fruit. This recognition of a foreign marking pheromone occurs in a multitrophic context since both herbivore and parasitoid inspect, oviposit into, and mark the same substrate (e.i. fruit surface). In this Article Addendum, we further show that this recognition of a foreign pheromone is both context dependent and mediated by preimaginal conditioning.