Influence of temperature on adult Cydia pomonella (L.) (Lepidoptera: Tortricidae) longevity and response to monitoring traps.

Cydia pomonella (L.), the codling moth, is a major pest of apples in Washington State and worldwide, where apples are grown. Recent weather patterns have brought heat domes and consistently hot days to Washington State summers. Understanding the effects of temperature on adult codling moth longevity and capture in monitoring traps is important for estimating populations and projecting damage in orchards. Further, codling moth management has relied on phenology models, but changing climate conditions could challenge them. Little research has been conducted on the effect of temperature on adult codling moth response to pheromone monitoring traps or their longevity in field conditions. Here, we present results from multiple studies investigating the effects of temperatures ranging from 10 °C to 43 °C on adult moth capture and longevity. In 2 adult longevity studies, incubators and semi-field cages were used to measure the length of adult life under controlled and field temperatures, respectively. Both studies found that increased temperature decreased the length of the adult codling moth's lifespan. In 2 mark-release-recapture studies, capture in pheromone-baited traps increased with temperature. The inverse relationship between reduced adult longevity and increased capture at higher temperatures may be attributed to an increase in codling moth activity. Increased activity may raise the chance a moth encounters monitoring traps, but they expend greater energy reserves, leading to a decreased lifespan. Although the length of adult life decreased at high temperatures, the effect on capture in monitoring traps appears to be a greater importance in interpreting those captures.