Population Suppression of Trogoderma glabrum by Using Pheromone Luring for Protozoan Pathogen Dissemination

Subsequent generations of Trogoderma glabrum (Herbst) were substantially suppressed after a single introduction of protozoan pathogen spores, Mattesia trogodermae Canning, into dense, adult male populations via pheromone-baited, spore-transfer sites. When using simulated warehouse conditions and an experimental design for optimizitig pathogen dispersal, dense (32 F adults/m2), treated populations increased only 4-fold in the 1st posttreament generation (vs. a 24-fold increase in controls) and fell to below pretreatment levels by the 2nd generation (vs. a total 100-fold increase in controls). In low density tests (2 F adults/m2), treated populations and controls increased 12-fold during the 1st generation. A 48-h exposure of pheromone-spore-transfer sites was sufficient to distribute effective spore doses within a radius of 1.25 m around sites in the dense population tests. Spore transfer from sites to subsequent T. glabrum generations was mainly by larval ingestion of either dead, contaminated adults, or larval food which adults had contaminated by contact. Treatment of spore-transfer sites with synthetic sex pheromone, ( E )-14-methyl-8-hexadecenal, attracted males and also induced attempted copulation with the pheromone source, aiding in spore transfer to males.