De novo synthesis of short‐chain aldehydes and hydrocarbons secreted by the brown marmorated stink bug Halyomorpha halys

Most heteropterans release pungent or characteristic secretions that help protect them against predators and pathogens. However, the biosynthesis of these secretions is poorly understood. The secretion of the brown marmorated stink bug Halyomorpha halys (Hemiptera: Pentatomidae) mainly comprises 4‐oxo‐( E )‐2‐hexenal, ( E )‐2‐decenal and tridecane, a mixture representative of that released by many heteropterans. Here, we used a feeding assay demonstrated to show that the secretory components of H . halys contained 13 C atoms derived from 13 C‐labelled glucose. Thus, we show that H . halys can synthesise myristic, palmitic, stearic, palmitoleic and oleic acids de novo , but not linoleic acid. These results suggest that the secretory components of H . halys are synthesised from acetyl‐CoA generated through glycolysis or chain shortening of saturated fatty acids via β‐oxidation pathway.