Behavioral correlates for minor volatile compounds from stink bugs (heteroptera: Pentatomidae)

Many terrestrial Heteroptera have small, but functional, dorsal abdominal glands as adults. The chemistry, and associated intra- and interspecific behavior, for dorsal abdominal gland secretions from 10 species representing four genera of Pentatomidae was investigated. Eighteen volatile compounds were identified in species-specific blends from the dorsal abdominal gland secretions of Euschistus, Acrosternum, and Eurydema adults, including aliphatic, aromatic, and terpenoid constituents. Evidence from bioassays is presented that parasitic Tachinidae (Diptera) and Scelionidae (Hymenoptera) use these secretions as kairomones. A field experiment was performed to test the hypothesis that minor volatiles increase the specificity of the main pheromone component from Nearctic Euschistus species, methyl (2E,4Z)-decadienoate. However, significantly fewer individuals of E. tristigmus were captured in traps baited with the complete blend for this species than in traps baited with methyl (2E,4Z)-decadienoate alone. Thus, at the concentrations tested, these kinds of dorsal abdominal gland secretions may be epideictic, promoting spacing in the natural habitat.