Male-specific volatiles from Nearctic and Australasian true bugs (Heteroptera: Coreidae and Alydidae)

Aeration and exocrine gland extracts were analyzed for three Coreidae and two Alydidae. Males of all the species studied emit volatile blends that are probably pheromones, but sexual communication in these insects evolved differently. In the alydids, Riptortus serripes and Mirperus scutellaris, the metathoracic scent glands are sexually dimorphic, and the dimorphisms are expressed chemically. Secretions from the male alydids contain high concentrations of esters or alcohols [e.g., (E)-2-hexenyl (Z)-3-hexenoate, (E)-2-hexenyl butyrate, and (E)-2-octenol], while females produce mainly acids and aldehydes [e.g., butyric and hexanoic acids, and (E)-2-hexenal]. In the coreids, Amblypelta lutescens lutescens, Amblypelta nitida, and Leptoglossus phyllopus, the metathoracic scent glands are not sexually dimorphic, but male- and species-specific volatiles are released, apparently from cells in the cuticular epidermis. The coreid male-specific volatiles are primarily monoterpenes and sesquiterpenes, including (-)-(3R)-(E)-nerolidol as the major component from A. lutescens lutescens (an Australasian species) and L. phyllopus (a Nearctic species). Only (+)-(3S)-(E)-nerolidol is commonly found in plant so (E)-nerolidol from these coreids is environmentally unique because of its chirality