2011 Annual Report
1a.Objectives (from AD-416)
1. To increase colony strength for pollination of almonds and subsequent crops; 2. To demonstrate that resistant stocks reduce costs and increase survivorship; 3. To demonstrate improved parasitic mite control with proper timing of management applications; 4. To improve the content and delivery methods for carbohydrate and protein diets to improve nutrition; 5. To improve the integrated use of controls for pests and pathogens, including non-chemical beekeeping techniques; 6. To decrease the level of pesticide contamination within bee hives; 7. To determine the economics of areawide IPM techniques utilized in the Program; 8. To communicate findings of the program to stakeholders in a timely fashion; 9. To protect the purity of honey; and 10. To increase beekeeping profitability.
1b.Approach (from AD-416)
An Areawide Oversight (CORE) Team comprised of representatives from the National Program Staff, the Center/Location management staff, ARS key scientists, Federal and State agencies, and when appropriate, commodity group, beekeepers and university representatives. The program is comprised of four key components within a framework of the temperal-spatial scale and three phased implementation. The four key components are operations, assessment, research and education.
Beekeepers often feed colonies dietary substitutes for nectar and pollen when flowering plants are unavailable. However, supplemental feeding can have deleterious effects on colonies if used for prolonged periods. We investigated the causes of two large losses of commercial colonies in California. The colonies were fed supplemental protein, but had low protein levels in workers. Low protein levels reduced brood rearing and shortened worker lifespans causing the colony populations to decline and the hives to perish. Beekeepers also fed sugar syrup to colonies as a carbohydrate source. Our studies demonstrated that during the winter when colonies are fed sugar syrup made with sucrose, they have higher rates of brood production in the spring compared with colonies fed high fructose corn syrup (HFCS).
We examined the effects of feeding pollen contaminated with fungicides on the diversity of microbes in the honey stomach and bee bread throughout the year in commercial colonies. Data on colony growth and survival also were collected. Complementary studies were conducted in our controlled flight area where bees were fed exclusively on pollen collected in the orchards where colonies were placed for pollination. Physiological measurements associated with food digestion and metabolism (e.g., hypopharyngeal gland development, protein concentration in bees) are being made along with measurement of colony growth and survival. Hypopharyngeal gland development did not differ between colonies fed pollen with and without fungicides, but protein concentrations in bees were significantly lower in the fungicide treatment. Colonies that were fed fungicide treated pollen had significantly lower rates of queen replacement success than those fed pollen without fungicides.
A new product that uses beta plant acids to control Varroa. Varroa is the most important pest of honey bee colonies and causes major colony losses due to parasitism and transmitting viruses many of which are assocated with Colony Collapse Disorder. The product, Hopguard, was tested in commercial colonies and packaged bees used to start new colonies. The product controlled Varroa when applications were made during the broodless period in January and then again in the early and late summer. The product did not substantially reduce mite populations in heavily infested colonies when only a single summer treatment was applied. A Varroa treatment schedule based on our field data and simulations with our Varroa population dynamics model is being developed and field tested in commercial colonies in California. Reducing mite populations in package bees followed by well timed applications of Hopguard throughout the year can keep mite population below levels that cause injury to colonies.