|Jones, Gregory - UNIV OF FL, GAINESVILLE|
|Sieving, Kathryn - UNIV OF FL, GAINESVILLE|
|Avery, Michael - USDA NWRC, GAINESVILLE|
Submitted to: Crop Protection Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 29, 2004
Publication Date: January 1, 2005
Citation: Jones, G.A., Sieving, K.E., Avery, M.L., Meagher Jr, R.L. 2005. Parasitized and non-parasitized prey selectivity of insectivorous bird. Crop Protection Journal. 24(2):185-189. Interpretive Summary: Natural enemies of pest insects in agroecosystems include arthropod species plus non-arthropods such as reptiles and birds. Since the development of inorganic insecticides in the 1950s and 1960s, few studies have looked at bird insect predators in modern cropping systems. Birds may help stabilize and improve pest control by consuming prey that escapes mortality from insect predators and parasites. This report focuses on research conducted by the Center for Medical, Agricultural and Veterinary Entomology, Gainesville, Florida in collaboration with colleagues from the University of Florida. The research asked that birds prefer to attack non-parasitized caterpillar prey. Results showed that birds did not exhibit a preference between parasitized and non-parasitized caterpillars of the same size; however, birds did exhibit a significant preference for larger non-parasitized caterpillars versus the smaller parasitized prey of the same age. This study suggests that birds may indeed improve biological control when arthropod pests that escape control become distinctly different in body size.
Technical Abstract: Conservation of biological control measures involves efforts to enhance the presence of naturally occurring enemies of pest arthropods in agroecosystems. However, little work has been done looking at avian insect predators in modern cropping systems to fill this role of integrating other control measures. Birds might stabilize and improve pest control by consuming prey that escapes mortality from other agents. We tested the hypothesis that birds prefer to forage upon non-parasitized fall armyworm [Spodoptera frugiperda (J. E. Smith) prey via captive feeding trials where birds were also offered prey parasitized by Euplectrus plathypenae (Howard) (Hymenoptera: Eulophidae). Birds did not exhibit an initial preference or an overall preference between simultaneously presented parasitized and non-parasitized prey of the same size. However, birds did exhibit a significant initial preference for larger non-parasitized armyworms versus the smaller parasitized prey of the same age. Birds also showed a significant overall preference for the larger non-parasitized prey even while this prey item became increasingly less numerous during each trial. While birds were equally willing to eat both parasitized and non-parasitized fall armyworm prey of the same body size, they exhibited a strong preference for the larger non-parasitized prey. Results of this study suggest that birds may improve biological control programs when arthropod pests that escape control become different in body size and become a favored prey item.