Title: A system for harvesting eggs from the pink-spotted lady beetle Authors
Submitted to: Psyche
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 15, 2012
Publication Date: March 26, 2012
Citation: Allen, M.L., Riddick, E.W. 2012. A system for harvesting eggs from the pink-spotted lady beetle. Psyche. Vol.2012,Article ID 923653,6 pages,2012. Doi:10.1155/2012/923653. Interpretive Summary: Pink spotted lady beetles are native to North America. They eat soft-bodied pest insects and spider mites and are therefore beneficial predators. They could be released into gardens and greenhouses for biocontrol of crop pests. They could also be used in genetics research in the laboratory, if they produce eggs in sufficient quantities. We found that this beetle laid a suitable quantity of eggs on a textured (rather than a smooth) artificial substrate in clear plastic (communal) cages, if crowding of male and female cohorts was not excessive. We also found that methyl salicylate (oil of wintergreen) was attractive to beetles but did not stimulate egg laying. We report the utility of a prototype cage and egg substrate system fashioned from simple materials readily available in most laboratories. Research is ongoing to improve the design of the cage to reduce cannibalism (under crowded conditioins) and maximize egg production.
Technical Abstract: We describe a system for harvesting eggs from a predatory insect, the pink spotted lady beetle. Coleomegilla maculata De Geer (Coleoptera: Coccinellidae). Adult beetles placed in square transparent containers that included oviposition substrates hanging from the top of the cage deposited eggs on the materials provided. We harvested eggs from these substrates in quantities sufficient for either destructive sampling or synchronous development of larvae. We evaluated effects of crowding inside cages; effects of a chemical attractant on oviposition behavior; and egg cannibalism. Females preferred textures surface rather than the smooth one for laying eggs. Crowding inhibited oviposition of beetles. Presence of a chemical attractant (methyl salicylate) did not significantly improved oviposition. This study describes an inexpensive system for harvesting eggs from C. maculata. Refinement of this system should improve oviposition and reduce cannibalism.