Quantification and Enhancement of Bat Predation on Noctuid Crop PestsEPA Grant Number: U916164
Title: Quantification and Enhancement of Bat Predation on Noctuid Crop Pests
Investigators: Gillam, Erin H.
Institution: University of Tennessee - Knoxville
EPA Project Officer: Cobbs-Green, Gladys M.
Project Period: January 1, 2003 through January 1, 2006
Project Amount: $145,172
RFA: STAR Graduate Fellowships (2003) Recipients Lists
Research Category: Fellowship - Terrestrial Ecology and Ecosystems , Academic Fellowships , Ecological Indicators/Assessment/Restoration
The objective of this research project is to study the coevolved, predator-prey relationship between Mexican free-tailed bats (Tadarida brasiliensis mexicana) and noctuid crop pests to assess the agronomic benefits bats provide to agriculture in south central Texas. Noctuid moths are among the world's most destructive agricultural pests, attacking a wide range of food and fiber crops. These moths also are among the favored foods of bats, which are voracious predators of night-flying insects. Although bats have been cited as being valuable to agriculture in the past, no controlled quantitative studies have examined the effects of predation by bats on reducing the crop damage caused by pest insects. The specific objectives of this research project are to: (1) quantify the benefits of bats to agriculture; (2) manipulate the impact of bats on infestations of crops by noctuid insects; (3) determine the effects of simulated echolocation on the reproductive success and growth of insect populations; and (4) establish the use of simulated ultrasound for integrated pest management as a practical approach for enhancing the natural biological control services provided by bats. Effects will be quantified from video observations of moth and bat activity, measures of bat foraging and feeding success obtained using ultrasonic bat detectors, and field surveys of adult moth mating and oviposition activity.
Noctuid moths detect and avoid the ultrasonic echolocation calls of bats, and the risk of predation by bats, as indicated by the detection of their calls, which inhibits mating and oviposition by moths. Bats also are attracted to areas where the calls of other bats indicate successful feeding. Complex, randomly varying arrays of combinations of ultrasonic pulses that closely mimic the echolocation calls of Mexican free-tailed bats will be broadcast over experimental field plots of corn and cotton in south central Texas. Corn earworm moths (Helicoverpa zea) are a major crop pest and will be used as a model species for this study.