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

Area of Science:

• Entomology
• Chemical Ecology
• Insect Behavior

Background:

• Terrestrial Heteroptera, particularly Pentatomidae (stink bugs), possess functional dorsal abdominal glands in their adult stage.
• These glands secrete volatile compounds that play roles in insect communication and ecological interactions.

Purpose of the Study:

• To investigate the chemical composition of dorsal abdominal gland secretions from ten Pentatomidae species across four genera.
• To determine the role of these secretions in intra- and inter-specific behaviors, including interactions with natural enemies.
• To test the hypothesis that minor volatiles enhance the specificity of aggregation pheromones in Nearctic Euschistus species.

Main Methods:

• Gas chromatography-mass spectrometry (GC-MS) was used to identify volatile compounds in the gland secretions.
• Bioassays were conducted to assess the role of secretions as kairomones for parasitic insects (Tachinidae and Scelionidae).
• Field experiments with pheromone traps were performed to evaluate the effect of complete blends versus single compounds on insect capture.

Main Results:

• Eighteen volatile compounds, including aliphatic, aromatic, and terpenoid constituents, were identified in species-specific blends.
• Parasitic Diptera (Tachinidae) and Hymenoptera (Scelionidae) were found to use these secretions as kairomones.
• Field experiments indicated that fewer Euschistus tristigmus were captured with a complete blend compared to the main pheromone component alone.

Conclusions:

• Dorsal abdominal gland secretions of Pentatomidae contain complex, species-specific volatile blends.
• These secretions serve as kairomones for natural enemies and may function as epideictic signals promoting spacing in natural habitats at tested concentrations.
• The findings challenge the sole role of these secretions as aggregation pheromones, suggesting a more complex ecological function.