2012 Annual Report
1a.Objectives (from AD-416):
To quantify the timing and abundance of the late-season arrival of migrant crop pest insects, and their impact on foraging behaviors and body condition of Brazilian free-tailed bats.
1b.Approach (from AD-416):
Several species of crop pest insects (corn earworm, fall armyworm, cabbage looper and stink bugs) will be collected daily from pheromone traps and blacklight traps to identify return (i.e., southward) migration events in central TX (Uvalde and College Station). Bats returning to Frio Cave (near Uvalde) from nightly foraging flights will be netted, and fresh fecal pellets will be collected. The fecal pellets will be analyzed to determine the presence of several insect species in the diet of bats. Temporal changes in the fecal DNA will be correlated with daily insect collections and weather conditions. Changes in timing, locations, and altitudinal distribution of feeding activity of bats will be documented in relation to movements and availability of crop pest insects.
The goal of this project is to define the relationships between migratory behavior of key crop pest insects and the foraging activity and overall health of Brazilian free-tailed bats that prey on these insects. In FY 2012, corn earworm, fall armyworm, and cabbage looper moths were captured nightly in pheromone traps and blacklight traps at Uvalde and College Station, Texas. Captures of corn earworm moths were one or two orders of magnitude (10 to 100 fold) greater than those of cabbage looper and fall armyworm moths. The average weight of bats at Uvalde increased in synchrony with a substantial increase in the number of trapped moths in late September. Further, late-season increases in the abundance of migrant pest insects in central Texas were associated with the passage of cold fronts. Work under this project, as it progresses, will continue to develop valuable information on the interactions and interrelationships between major crop insect pests and bats that consume these insects by the millions.