Pre- and Postseason Field Tests with Disparlure, the Sex Pheromone of the Gypsy Moth, to Prevent Mating

Out-of-season field tests on 16-ha plots were conducted in 1972 to develop means of using disparlure in controlling Porthetria dispar (L.) either by mass-trapping of males or with disparlure-containing formulations that divert male moths in their attempts to find mates. In tests begun early in April on Dauphin Island, AL, small tube traps (25/ha; each coated inside with adhesive containing 500 μ g disparlure) suppressed moth captures in disparlure-baited monitor traps 94% for 7 weeks. A 6/12-mesh-cork formulation (applied at a rate of 8.2 g disparlure/ha) suppressed captures 99% for 7 weeks. A molecular-sieve formulation (8.2 g lure/ha) began to fail ca. 1 month postapplication. A 2nd series of tests was conducted in the natural habitat of the moth on Cape Cod, MA, starting in late May using monitor traps baited with either disparlure or live virgin females. Although the 6/12 cork formulation (11.1 g lure/ha) failed when tested 33 days postapplication, a fine-cork formulation and a microcapsule formulation (11.1 and 1.8 g lure/ha, respectively) remained effective for 6 weeks despite heavy rains, probably because they included a sticker to anchor them to foliage. In postseason tests on Cape Cod, 1 molecular-sieve and 3 microcapsule formulations suppressed catches of released males 90% or more (vs. no treatment) when tested 6½ and 8 weeks posttreatment.