Monday, December 10, 2007
D0109

Overwintering survival of the multicolored Asian lady beetle (Coleoptera: Coccinellidae): The influence of autumn feeding on wine grapes

Tederson L Galvan, galva008@umn.edu1, Robert L Koch, Robert.Koch@state.mn.us2, and William D Hutchison, hutch002@umn.edu1. (1) University of Minnesota, Entomology, 219 Hodson Hall, 1980 Folwell avenue, Saint Paul, MN, (2) Minnesota Department of Agriculture, Invasive Species Unit, 625 Robert Street North, Saint Paul, MN

The establishment of the multicolored Asian lady beetle, Harmonia axyridis (Pallas), in North America has resulted in negative impacts on fruit production. In this study, we investigated the overwintering survival of H. axyridis after feeding on four diets: injured wine grape berries, sucrose solution 25%, water, and an untreated check. After being exposed to these diets for 6 days, live individuals were transferred to clean plastic Petri dishes, and held at 5 ± 1°C in growth chambers throughout the winter. Survival was recorded every month. Adult lady beetles collected during the overwintering flight in mid-October had higher survival than beetles collected from soybean fields in mid-August. Therefore, an adaptation period prior diapause increases the chances of lady beetle survival during winter. In addition, injured wine grape berries, sugar and water improved the tolerance of beetles to mortality due to starvation or cold during the overwintering months. Our results also showed that under similar conditions females have higher chances to survive over the winter than males. The importance of sugar and water on winter survival may be a significant factor governing the movement of H. axyridis adults to vineyards and feeding on wine grapes.


Species 1: Coleoptera Coccinellidae Harmonia axyridis (multicolored Asian lady beetle)