SEASONAL DEVELOPMENT AND FLIGHT ACTIVITY OF THE SPOTTED TENTIFORM LEAFMINER, PHYLLONORYCTER BLANCARDELLA (LEPIDOPTERA: GRACILLARIIDAE), IN CONNECTICUT

Abstract

AbstractThe spring emergence and seasonal abundance of the trivoltine spotted tentiform leafminer, Phyllonorycter blancardella (Fabr.), were monitored in a Connecticut apple orchard to provide phenological data for control programs. Spring emergence of each sex lasted 28 or 29 days in 1980 and 1981 although large emergences (≥5% of the total) occurred over a period of 12 to 18 days. When spring emergence was forecast in 1981 by using degree-day accumulations (above 5 °C) from the 1980 emergence, the predicted and actual 10 and 50% emergence time differed by 4 or 5 days. Even though daily catches of moths in pheromone traps preceded those in emergence traps, the abundance patterns indicated by these traps were similar. Low temperature and rain reduced emergence and flight activity. Seasonal abundance in pheromone traps showed three or four peaks, which usually decreased in size as the year progressed. From 1978 to 1981, the onset of male flight activity varied by as much as 3 wk. When emergence and pheromone traps are used together, they indicate the duration and peaks of emergence and flight activity.