Reproductive Refractoriness in the Western Tarnished Plant Bug (Hemiptera: Miridae)

Adult Lygus hesperus Knight (Hemiptera: Miridae), major crop pests of the southwesternUnitedStates, canmate repeatedlyduring their lives, potentiallyenhancing the lifetimeÞtness ofboth sexes.However, theperiodicityofmating and its regulation in this species is poorlyunderstood. In this study the postmating refractory period for both sexes is described. Males were found to have a median delay of 24 h, which seems to be the minimum time needed to reÞll the accessory glands and produce another viably sized spermatophore. Themedian refractory period inmated females was 5 d, but sometimes lasted longer than 2 wk. The loss of sexual receptivity in mated females, at least for the Þrst 24 h, seems to be induced by males; spermatophore homogenates injected directly into the abdomen of virgin females reduced their sexual receptivity. The total duration of female refractoriness may be dictated by the starting size of a spermatophore and the rate at which it degrades.