Location: Bee Research Laboratory2013 Annual Report
1a. Objectives (from AD-416):
The objective of this program is to improve overall colony survival and availability for pollination by bringing together recent ARS research findings on mite-resistant bee stocks, improved diets, mite and disease control alternatives and general colony management techniques into a comprehensive bee management system. The overarching goal of this Areawide 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 recent ARS research including: 1) two ARS bee stock improvements, Russian bees and the Varroa Sensitive Hygiene (VSH) trait (Baton Rouge); 2) improvements in nutrition, Mega Bee® (Tucson), 3) parasitic mite management techniques including new chemical controls 2-heptanone (Tucson), and non-chemical controls plastic drone comb (Beltsville) and screen bottom boards (Beltsville); 4) management practices including the use of antibiotics, Tylosin® (Beltsville) and Nosema controls (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 tests in many geographic regions as bees and bee pests and diseases grow at different rates in different parts of the country.
3. Progress Report:
Experiments were conducted to determine the level of pesticide exposure in 8 crops across the U.S. Honey bee colonies collected pollen on crops such as apple, almond, watermelon, blueberries, squash and others that use bees for pollination. On average the incoming pollen contained 9 pesticides with fungicides being the most prevalent. When these pollens were fed to bees in the laboratory there was a significant increase in the gut pathogen Nosema when the fungicide chlorothalonil was present in the pollen. Pesticide pathogen interactions had been demonstrated before but this was the first study to test “real world” mixtures of pollens collected from crops being pollinated by honey bees. These lab and field studies combined demonstrate the need to continue to monitor bee colonies for pesticide exposure. Both the lab study and the field collections represent real-world pesticide exposures on bee-pollinated crops and demonstrate the need to limit pesticide exposure to improve honey bee health. Honey bee colony losses in the U.S. were surveyed for the seventh year in the fall and winter of 2012-13. The overall losses, due to a variety of causes, were 31%. Colony Collapse Disorder (CCD) symptoms were reported to a lesser degree than previous years. Scientists at the Bee Research Laboratory in Beltsville, Maryland, are currently testing means to limit the negative effects of queen loss, transportation and other stress factors to provide solutions for beekeepers who must move bees to meet pollination demands of U.S. agriculture. Most honey bee losses due to CCD occur in the late fall and winter in advance of almond pollination and many of these colonies originate in the mid-west. A study was initiated in 2009 that placed commercial colonies in pollen rich and pollen poor areas to determine if resource availability was driving at least a portion of the colony losses. Two hundred and eighty eight colonies were monitored at a total of 6 sites with half the colonies at each site being fed supplemental protein (MegaBee) in the late summer and fall. Colonies at poor sites produced lighter weight worker bees with lower storage proteins (vitellogenin) levels, and feeding supplemental protein at these sites increased individual bee weights. Honey production and colony strength were positively associated with those sites than a wider diversity of plants. An extension Web site, launched in July 2008 to provide a platform for information exchange on honey bee issues, has been upgraded and improved by incorporating user feedback and the placement of recent research findings on the site for ready access by the public. Publications will be made available on the site along with a more user friendly synopsis of each publication. A new NIFA-CAP extension based grant called the Bee Informed Partnership (BIP) was initiated two years ago and data from the Areawide project will help to populate a large data set on pests and disease levels across the U.S. to be used as a decision making tool by beekeepers.
1. Effect of transportation on honey bees. BRL scientists in collaboration with Michigan State University demonstrated that long-distance transportation adversely affects individual worker bees and thus may impact the colony as a whole. Worker bees in colonies that moved had smaller glands that they use to feed immature brood in the colony. These smaller brood food glands would limit the amount of new young bees that could be raised and thus reduce the adult bee population over time. This is valuable information for beekeepers and a better understanding of migratory stress should allow for the development of techniques to limit this stress such as increased water availability during the move and possible refrigeration during transport, to mention just two ideas. Means to limit migratory stress are needed as the need for pollination, and thus colony transport, continues to increase in U.S. agriculture.
2. Pesticide-gene expression interactions. BRL scientists demonstrated that sub-lethal pesticide exposure can cause changes in metabolic response in worker honey bees that may alter bee health. These changes include changes in detoxification pathways and changes in immune response. Interactions between pesticides and gene expression will help us better understand the negative effects that pesticides have on individual bees and could aide in our development of strategies to limit the recent declines in honey bee colony health.
3. Causes of honey bee winter declines. BRL scientists collaborated with the Apiary Inspectors of America, USDA-APHIS and the University of Maryland on a national survey to document colony losses. This survey, now in its seventh year, provides the only data on colony losses in the U.S. and the survey questions have been harmonized with European colleagues to allow for comparison of data collection in Europe.
Boncristiani, H., Underwood, R., Schwarz, R.S., Evans, J.D., Pettis, J.S., Vanengelsdorp, D. 2011. Direct effect of acaricides on pathogen loads and gene expression levels of honey bee Apis mellifera. Journal of Insect Physiology. 58:613-620.