Location:2011 Annual Report
1a. Objectives (from AD-416)
The Areawide Program will bring together recent improvements in mite-resistant bee stocks, nutrition, and pest and disease management techniques into a comprehensive management strategy to improve honey bee health in the U.S. The objective of this program is to increase colony survival and availability for pollination and thus increase the profitability of beekeeping in the U.S.
1b. Approach (from AD-416)
The program will focus on bringing together ARS research from Beltsville, MD; Tucson, AZ; Baton Rouge, LA and Weslaco, TX. Specific objecives include: HFCS research results (Weslaco); 3) parasitic mite management techniques including new chemical controls 2-heptanone (Tucson), Hivastan (Weslaco) and non-chemical controls plastic drone comb (Beltsville) and screen bottom boards (Beltsville); 4) Nosema controls (Weslaco and Beltsville). A year-round management scheme will be tested in large migratory and smaller non-migratory beekeeping operations with an emphasis on the larger migratory beekeepers that supply bees to almonds (almost half of all managed bees in the U.S.). The country will be divided into geographic regions as follows: East, Mid-West & West. It is imperative to test in many geographic regions as bees, bee pests and diseases grow at different rates in different parts of the country.
3. Progress Report
A field study with 400 colonies was conducted in southern Louisiana. Treatment groups included all combinations of three stressors: nutrition, varroa, and nosema. Colonies were moved to California for February-March almond pollination and then returned for honey production. Colonies starting this experiment with ca. 150 varroa dropping naturally onto a sticky board during a 72-hour period were generally unable to meet a 6-frame minimum strength criterion no matter what palliative treatment or feeding was received. Colonies with initial high mite loads showed significantly depressed honey production, underscoring the fact that Varroa destructor control remains the single most important problem for U.S. beekeepers. After 14 months, colonies not treated with fumagillin showed severe strength reduction (ca. 3 vs. 11 frames of bees). Colony survival was highest for those receiving protein supplements, amitraz (varroa control), and fumagillin (nosema control). Survival was poorest for those that received only one of the possible treatments (food, either palliative, or nothing). Colony death was, in almost all cases, preceded by queenlessness. Surprisingly, these colonies did not attempt normal supersedure or emergency queen cell construction. The length of time a queen survived was inversely correlated with the number of varroa, and to a lesser degree, the nosema level at the start of the experiment. We examined the impact of colony density on almond nut set. This is the second year of this project. During February and March 2011, we conducted an experiment in cooperation with Scientific Ag and Wegis Farms, Bakersfield, CA. Almond growers have reduced the colonies/acre normally used because of elevated colony rental cost. This reduction has alleviated to a degree the colony shortage experienced a few years ago. This project is attempting to understand the economic impact on nut harvest. Paired orchards (by cultivar, age, management, and proximity) were selected on Wegis Farms and a local beekeeper contracted to supply quality colonies (10+ frame average). Nut set in both early cultivars and late hard-shell cultivars were monitored. Data is still being analyzed and a final nut harvest has yet to be made, but it is clear that increasing the colony density resulted in a significant (and substantial) increase in set.