Field Bioassays of Synthetic Pheromones and Host Monoterpenes for Conophthorus coniperda (Coleoptera: Scolytidae)

Four major monoterpenes, (±)- α -pinene, l( S )-(–)- β -pinene, ( R )-(+)-limonene, and myrcene are found in the cones of eastern white pines, Pinus strobus L. Mixtures of these, as well as, α -pinene or β -pinene alone, increased catches of male white pine cone beetles, Conophthorus coniperda (Schwartz), in traps baited with the female sex pheromone, (±)- trans -pityol. The monoterpenes by themselves as mixtures or individually ( α -pinene, β -pinene) were not attractants for males or females. Traps baited with (±)- trans -pityol and α -pinene caught as many, or significantly more beetles than those baited with pityol and a four monoterpene mixture (1:1:1:1) used in seed orchards in North Carolina, Ohio, and Virginia. Three beetle-produced compounds, conophthorin, trans-pinocarveol, and myrtenol did not enhance catches of males or females in (±)- trans -pityol-baited traps. Racemic E -(±)- conophthorin, E -(−)- conophthorin, and E -(+)- conophthorin significantly reduced catches of males in traps baited with (±)- trans -pityol alone. Female C. coniperda were not attracted to any of the host- or beetle-produced compounds tested. The study demonstrated that traps with baits releasing (±)- trans -pityol at about 1mg/wk with (±)- α -pinene (98% pure) are potentially valuable tools for C. coniperda pest management. Baited traps can be used to monitor C. coniperda populations or possibly to reduce seed losses in a beetle trap-out control strategy.