Effect of dispenser type, trap design and placement on catches of pine-tree lappet moth, Dendrolimus pini

Dendrolimus pini is one of the most harmful defoliators of Scots pine in Poland and other countries in Europe and Central Asia. The monitoring of this insect needs to be improved and to include the use of pheromone traps. Laboratory studies were conducted to compare changes in the residual amounts of ( Z,E )-5,7-dodecadienal and ( Z , E )-5,7-dodecadien-1-ol, the major components of the D. pini pheromone, in four types of dispensers. The two most promising dispensers, red rubber cylindrical dispensers (rubber cylinders) and polyethylene vials, were tested in the field for their ability to attract D. pini males. In addition, the effects of trap type (sticky wing, non-sticky cross-vane, bucket, funnel and modified gypsy moth milk carton) and height of trap placement (1.5 m, 5–6 m and tree crown) on trap catches were tested in the field. The vials provided the longest half-lives for both the aldehyde and alcohol under laboratory conditions. These dispensers were also significantly more effective in attracting D. pini males to the traps than the rubber cylinders in the field experiment. The cross-vane and bucket traps were the most effective among the tested traps. The height of trap placement had a significant effect on catches, with more males caught in traps that were hung at 5–6 m above the ground than those hung in the tree crowns. Our results may be useful for developing a monitoring system for D. pini in Europe and other regions where it occurs.