Gypsy moth (Lepidoptera: Lymantriidae) flight behavior and phenology based on field-deployed automated pheromone-baited traps.

Populations of the gypsy moth, Lymantria dispar (L.), are extensively monitored in the United States through the use of pheromone-baited traps. We report on use of automated pheromone-baited traps that use a recording sensor and data logger to record the unique date-time stamp of males as they enter the trap. We deployed a total of 352 automated traps under field conditions across several U.S. states over a 5-yr period. In many cases, there was general congruence between male moth capture and the number of recorded events. Although it was difficult to decipher an individual recording event because of the tendency for over-recording, the overall distribution of recorded events was useful in assessing male gypsy moth flight behavior and phenology. The time stamp for recorded events corroborated a previous report of crepuscular gypsy moth male flight behavior, because, although most moths were trapped between 12 and 16 h, there was a consistent period of flight activity between 20 and 22 h. The median male flight duration was 24 d (228 DD, base threshold = 10 degrees C), but there were several traps that recorded flight periods >42 d that could not be explained by overcounting given the congruence between moth capture and the number of recorded events. Unusually long flight periods could indicate the introduction of male moths or other life stages that developed under different climatic conditions.