BEHAVIORAL-CORRELATES FOR MINOR VOLATILE COMPOUNDS FROM STINK BUGS (HETEROPTERA, PENTATOMIDAE)

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