Bird-Repellent Properties of Secretions from Nymphs of the Azalea Lace Bug

Many insect species possess chemical defenses against avian predators. Here, we present a series of behavioral investigations designed to assess the repellency of secretions produced by nymphs of the azalea lace bug (Stephanitis pyriodes). In Experiment 1, adult and nymph lace bugs were presented to Red-winged Blackbirds (Agelaius phoeniceus). The results indicated that adults (which lack chemical secretions) were relatively more palatable. In Experiment 2, we dipped nymphs in methylene chloride to remove secretion, and then presented dipped and undipped insects to birds. Consumption of the former nymphs was significantly higher than consumption of the latter, providing strong evidence that nymphs are avoided because of secretions. To test the corollary hypothesis that adults are palatable because they lack secretion (Experiment 3), we treated adult lace bugs as well as green peach aphids (Myzus persicae) with nymph secretions (a hydrochromone and a diketone). Treated insects of both species were avoided while untreated insects were not. Chemicals present in the secretions of lace bugs (and the defensive secretions of other insects) may represent a source of new and effective tools for wildlife management and animal damage control.