DEVELOPMENT OF PHEROMONE-BASED MONITORING AND DETECTIONOF NUN MOTH, LYMANTRIA MONACHA L., POPULATIONS.

Petra Lange and Gerhard Gries
Dept. of Biological Sciences, Simon Fraser University, Burnaby, B.C.V5A 1S6

1) Lymantria monacha L. is an important defoliator of spruceand pine forest in central Europe. Potential introduction of L.monacha in N.America poses a severe threat to North American forests. Research objectives were: 1) to develop pheromone- based detection of L.monacha: In deciduous forests of 3 regions in Germany and theCzech Republic, Unitraps were suspended at ~15 m intervals from trees inrandomized complete blocks and were baited with four concentrations (2-2000mg) of (+/-)-disparlure or the new nun moth blend of (+/-)-disparlure (48%),(+/-)-monachalure (48%), and 2-methyl-Z7-octadene (4%). While (+/-)-disparlureattracted both male L. monacha and L. dispar (gypsy moth),the new pheromone blend attracted only males of L. monacha. A polyurethane-based dispenser with 2000 mg of the new blend is recommendedas a trap bait for species-specific, highly sensitive detection surveysof L. monacha in North America. 2) to develop pheromone-based monitoringof L. monacha populations: In spruce and pine dominated forestsaround Prague, Berlin, and Freiburg, non-saturating Unitraps and stickyDelta traps were suspended from trees at ~100 m intervals in randomizedcomplete blocks, and were baited with four concentrations (0.2-200 mg)of the new pheromone blend. Estimates of population densities at each trappingsites included counts of larval fecal pellets, and pupal cases and adultmoth on tree trunks. Total captures of males throughout the flightseason in Delta- and Unitraps were correlated with numbers of larval fecalpellets. Unitraps baited with 2 mg of pheromone in polyurethane baseddispensers seem appropriate for monitoring population densities of L.monacha.