Semiochemical release and ontogenetic changes in a primary scent gland of Podisus maculiventris

Abstract

Abstract Podisus maculiventris (spined soldier bug) is a generalist predator studied for its biocontrol potential. This species has a large dorsal abdominal gland (DAG) that releases pheromones that can also be important semiochemicals for other organisms. Despite our growing understanding of gland development, the conditions that elicit releases are largely unknown. To determine if male age or gland development affects the chemical composition and release behavior, we dissected adult male bugs and profiled the chemical composition of the male DAG 1, 7, and 14 d post-eclosion. To determine if gland development is related to sexual maturity, we counted the number of sperm present in the seminal vesicles at the same time points. Finally, we measured the diurnal release patterns of different aged males and in various male-female combinations. We observed that newly eclosed adults have under-developed glands and male seminal vesicles contained few sperm. One week post-eclosion the DAG contained previously reported pheromone compounds and males contained many sperm. Mirroring the trend in reproductive maturation and gland development, the number of pheromone releases increased with age and the majority of releases followed a scotophase pattern unaffected by sexual composition. These findings link male age to 1) dorsal abdominal gland development 2) release behavior and 3) sexual maturity, which will help our understanding of when these olfactory cues are present for other organisms, like prey, to perceive.