Many insect species use multi-component sex pheromone to discriminate among potential mating partners. In moths, pheromone blends tend to be dominated by one or two major components, but behavioral responses are frequently optimized by the inclusion of less abundant minor components. An increasing number of studies have shown that female insects use these chemicals to convey their mating availability to males, who can assess the maturity of females and thus decide when to mate. However, little is known about biological mechanisms that enable males to assess female reproductive status. Recently, researchers at State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection (IPP) at Chinese Academy of Agricultural Sciences (CAAS) published one paper on Current Biology about a novel mechanism of one pheromone antagonist cis-11-Hexadecenol (Z11-16:OH) employment in Helicoverpa armigera optimal mating times.

In this study, they found that females of H. armigera avoid nonoptimal mating by inhibiting males with Z11-16:OH. Such antagonist-mediated optimization of mating time ensures maximum fecundity. To further investigate molecular aspects of this phenomenon, they used the CRISPR/Cas9 system to knock out odorant receptor 16 (OR16), the only pheromone receptor tuned to Z11-16:OH. In mutant males, electrophysiological and behavioral responses to Z11-16:OH were abolished. Inability to detect Z11-16:OH prompted the males to mate with immature females, which resulted in significantly reduced viability of eggs. In conclusion, this study demonstrates that the sensitivity of OR16 to Z11-16:OH regulates optimal mating time and thus ensures maximum fecundity, which provides some novel strategies to disrupt pest insect mating. More details are available on the bellow link:
http://dx.doi.org/10.1016/j.cub.2017.04.035