Reproduction of the western tarnished plant bug, Lygus hesperus, in relation to age, gonadal activity and mating status.

Understanding the basic life history and underlying regulatory mechanisms for a pest insect is essential for developing targeted control strategies, but for many insects relatively little is known. Although the western tarnished plant bug, Lygus hesperus Knight (Heteroptera: Miridae) has a substantial negative impact in the western U.S., its basic biology is poorly characterized. To elucidate the regulation of L. hesperus reproductive dynamics, the onset times of gonadal activation and mating behavior were examined in young adults. Newly emerged adults reared under laboratory conditions at 25 degrees C were monitored daily for changes in gamete production and willingness to mate. Males matured more quickly than females. Sperm was present at emergence and a small proportion of males were willing to mate as early as 2 days post-emergence. Females were unwilling to mate until at least 5 days post-emergence, although many produced choriogenic oocytes by 4 days. Males appeared to discriminate female age and were more likely to attempt mating with females >5 days post-emergence than with younger females. Males were also able to detect previous mating and attempted to mount virgins more often than recently inseminated females. Collectively these results indicate that the changes in the mating behaviors of L. hesperus are linked to reproductive status, although there is a lag between gamete production and willingness to mate. The results also suggest that interactions of the sexes are chemically mediated.