Interactions among the tarnished plant bug (Lygus lineolaris) and its host plants: A study of volatile induction and implications for biological control

The tarnished plant bug, Lygus lineolaris is an important generalist Hemipteran pest in a number of fruit and agricultural systems. Both generalist insects and Hemipiterans are understudied in terms of their chemical ecology, and a greater understanding of L. lineolaris would benefit biological control efforts and contribute to basic knowledge of plant-insect interactions. Preliminary work described here demonstrates that L. lineolaris induces host plants to release specific blends of compounds that are qualitatively and quantitatively different relative to undamaged and mechanically damaged plants. This was observed in both a weedy host (Melilotus officinalis) as well as a cultivated host (Medicago sativa) and suggests that compounds in the salivary secretions of this piercing-sucking insect may elicit the observed volatile response. Previous work in the area of L. lineolaris biological control has demonstrated that the success of parasitoid natural enemies varies depending on the weed and crop community. The common field margin weed, Erigeron annuus, for example, is a refuge host for L. lineolaris. We found that E. annuus constitutively releases large amounts of the same compounds found to be induced by feeding in both M. officinalis and M. sativa. E. annuus may provide an olfactory refuge for L. lineolaris, or act as a beacon for natural enemies, although this has yet to be determined. Future work will examine the attractiveness of Lygus-induced volatile profiles to native and introduced L. lineolaris parasitoids with this goal in mind.