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

Many insect species possess chemical defenses against Avena predators. Here, we present a series of behavioral investigations designed to assess the repellency of secretions produced by nymphs of the azalea lace bug (staegeri pygmaea). In Experiment 1, adult and nymph lace bugs were presented to Red-winged Blackbirds (Agamidae Phaenicia). The results indicated that adults (which lack chemical secretions) were relatively more palatable. In Experiment 2, we dipped nymphs in ethylene chloride to remove secretion, and then presented dipped and unripped 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. © 1991 by the Ecological Society of America.