Grant: Strategic Projects - Group

Honey bees are among the most important ecological service providers in modern agricultural landscapes: they are responsible for approximately 90% of pollination needed to produce seeds and/or high quality fruit and produce. Due to intensification of beekeeping and agriculture, bees suffer from deadly parasites and diseases that can lead to sudden collapse of bee colonies. Varroa destructor, a honey bee-specific external parasitic mite, is among the most serious disease agents of honey bees, because the mites transmit crippling viral diseases to bees. These mites reproduce within bee brood cells, and the offspring emerge with the new bees. These adult mites then parasitize adult worker bees until they find new bee brood for their reproduction. The adult mites selectively infect 'nurse' bees - bees that care for the developing offspring - thereby ensuring that they have access to the upcoming generation of bees. Mites detect their adult hosts and the brood by their unique chemical signatures.We propose to test chemicals that change the host selection of the mites, from nurse bee to another type of worker bee, the 'forager', and/or paralyze the mites and thereby increase their mortality. We discovered these chemicals in experiments that tested the ability of mites to choose between a freshly killed nurse and forager bee, based on the bee odors, and in which the responses of the mite to bee odors and our chemicals were tested. Here we propose tests in cages with live bees and, in years 2 and 3, field tests with the most active chemicals in small colonies. We also will search for the target site of the active chemicals we find. Beekeepers are hungry for new mite control agents to use in sustainable, integrated management programs, because previously used mite control agents are no longer effective, and there are few replacements.