Location: Biological Control of Insects Research2012 Annual Report
1. Selecting highly fecund lines of beneficial insects. The concept of biological control of insects is a potentially powerful alternative to classical insecticides. A major challenge is, however, the high cost of mass-producing beneficial insects restricts global use of these agents. ARS scientists at Columbia, Missouri, in collaboration with researchers at the University of Nebraska, Lincoln, Nebraska, are working to reduce mass-production costs by selecting lines of predatory insects with increased egg-laying capacity. These selection programs depend on substantial genetic variability among individuals within the species of predatory insects. The researchers confirmed high genetic variability between populations from different geographic locations, providing the foundation for future work to breed a strain of spined soldier bugs with high reproductive capacity. Ultimately, this research will benefit growers who use biological control agents to reduce insect pest damage to their crops and consumers seeking food having reduced pesticide levels.
2. Improved baculovirus delivery for biocontrol. Lignin is a readily available, inexpensive, and renewable resource that could be used as an alternative to costly UV-protectants for naturally occurring baculoviruses selected for faster kill of crop-damaging caterpillars. ARS researchers at Columbia, Missouri and Peoria, Illinois explored lignin as an encapsulating agent that protects the baculoviruses from exposure to destructive ultraviolet (UV) light. In greenhouse and field experiments with cabbage, the researchers used a spray-dried lignin formulation to encapsulate a highly effective natural baculovirus and compare its persistence, rate of kill and replication to the wild-type strain. While the wild-type baculovirus proved more adept at replicating inside the caterpillars than the natural baculovirus, the caterpillars infected by the natural baculovirus died a day sooner than those infected by the wild-type strain. The lignin-encapsulated natural baculovirus killed the pests as quickly as lignin-free isolates, and lasted longer than lignin-free ones when exposed to UV radiation (27 versus 8 hours). This additional evidence of the formulation’s commercial potential will benefit growers by improving pest insect control and consumers who prefer organic and insecticide-free foods.Grasela, J.J., McIntosh, A.H., Ringbauer Jr, J.A., Goodman, C.L., Carpenter, J.E., Popham, H.J. 2012. Development of cell lines from the cactophagous insect: Cactoblastis cactorum (Lepidoptera: Pyralidae) and their susceptibility to three baculoviruses. In Vitro Cellular and Developmental Biology - Animals. 48:293-300.