Laboratory Studies of Variations in Feeding Behaviors Among <I>Lygus hesperus</I> (Hemiptera: Miridae) of Different Gender and Reproductive States

Abstract

Lygus hesperus Knight (Hemiptera: Miridae) is a key pest of cotton (Gossypium spp.) in the western United States that injures floral buds (squares) and developing fruit (bolls). Levels of Lygus-induced damage to cotton can vary by Lygus ages or gender, and these variations complicate interpretation of studies designed to elucidate Lygus and cotton interactions. Variations in observed injury may reflect different behaviors among Lygus gender or ages. We compared times allocated to feeding and trivial movement between male and female adult L. hesperus of different reproductive states: prereproductive, reproductive and mated, and reproductive and unmated. Prereproductive adults exhibited less trivial movement and spent more time stylet-probing compared with reproductive unmated and mated adults. Mated females stylet-probed more times than other classes of adults, whereas mated and unmated reproductive females exhibited more test probes (≤10 s duration) than prereproductive females. Reproductive females probed the anther region of squares less than prereproductive females. Instead, reproductive females tended to stylet-probe squares below the bracts, which is also where they oviposited. Each oviposition event was preceded by a short duration stylet-probe at the oviposition location. Unmated reproductive males exhibited more test probes but fewer ingestion probes (>1 min) compared with prereproductive and mated males. These results indicate a pattern in which prereproductive adults are less active and feed more compared with reproductive adults, but behaviors vary among reproductive adults of different gender and mating states. We propose that differences in behaviors exhibited among adult L. hesperus are related to the different requirements imposed by mate seeking, mate attraction, and oviposition.