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Grant Awarded To Combat Honey Bee Insect Pests - February 2003

February 18, 2003

UNIVERSITY PARK, PA - A Penn State Department of Entomology faculty member recently won a grant from the Northeast Regional Integrated Pest Management Grants Program to study innovative techniques of managing parasitic pests of honey bees.

Co-principle investigators Nancy Ostiguy, associate professor of entomology at Penn State, and Dewey Caron, professor of apiculture and extension entomologist at University of Delaware will be collaborating with Maryland beekeeper and extension specialist Mike Embrey to test integrated pest management (IPM) tactics to develop non-chemical control tactics for varroa mites.

IPM aims to manage pests -- such as insects, diseases, weeds and animals -- by combining physical, biological and chemical tactics that are safe, profitable and environmentally compatible.

Honey bees are essential to the pollination of over 90 fruit and vegetable crops worldwide and are valued at over $14 billion annually in the U.S. Populations of honey bees are in jeopardy due to the 1988 introduction of varroa mites, an external parasite similar to a tick and the major killer of all bee colonies in the U.S. In Pennsylvania, an average of 53 percent of managed honey bee colonies died between 1995 and 1996 from parasites like varroa, and in many regions of the U.S. nearly all feral honeybee nests have died. Increased losses have caused beekeepers to give up keeping bees, increasing the cost for growers who must lease hives to help pollinate their crops.

Current methods for varroa control have not been effective because many varroa mites have developed resistance to traditional pesticides. In addition, pesticide applications can cause adverse effects on exposed honey bees and potentially contaminate honey. Ostiguy believes that the project will help to improve the current management for varroa by providing a non-pesticidal alternative for varroa control. "By reducing pesticide use in colonies, residues in honey and other hive products will diminish, thereby reducing pesticide exposure for children and others," says Ostiguy. In addition, reducing pesticide use will slow the development of mite resistance and reduce pesticide exposure to honey bees.

The researchers hope to fulfill two objectives. "IPM tactics need to be integrated into beekeeper management practices. Our first objective will be to test the effectiveness of delaying queen release to reduce varroa levels in honey bee colonies," says Ostiguy. Since varroa mites require bee brood to lay their eggs, Ostiguy believes varroa reproduction will be interrupted if the honey bee reproduction is also temporarily interrupted. Caging existing queens, replacing existing queens and queen removal to trigger the making of a new queen would all interrupt bee and mite reproduction?

The second objective of the study will be to test the effectiveness of the delaying queen release or of queen caging tactics chosen from Objective 1 with screen bottom boards to reduce levels of varroa mites in honeybee colonies. "Previous research has indicated that screens provide a barrier between bees and live mites that have fallen off," explains Ostiguy. The researchers believe that in addition to providing a physical barrier, screens may also reduce the ability of mites to survive due to increased water loss from increased air movement.

Research for the project will be conducted at Penn State, the University of Delaware and the eastern shore of Maryland. Ostiguy says that testing the ability of the IPM tactics in multiple environments will increase the validity of the data collected.

The researchers hope to demonstrate that a combination of IPM tactics - temporary restriction of bee reproduction and screen bottom boards - will reduce mite reproduction and that these combined tactics can be used to keep mite levels below the damage threshold. "These tactics will be applicable to all regions of the country because beekeeping practices and varroa characteristics are similar throughout the country," Ostiguy explains. Once the results from two years of study are completed, the group plans to transfer the results to the beekeeping community by means of regional honey bee extension publications.

 

The Pennsylvania IPM Program is a collaboration between Penn State's College of Agricultural Sciences and the Pennsylvania Department of Agriculture aimed at promoting IPM in both agricultural and nonagricultural situations. For more information, call (814) 865-2839, or visit the program's Web site http://paipm.cas.psu.edu.