Varroa Mites Feed On The Fat Bodies Of Honey Bees, Not The Hemolymph. This Is Important!

Catch The Buzz By Dennis O’Brien January 30, 2019

cross section of honey bee abdomen.jpg

An image showing a cross section of a varroa mite feeding on a honey bee’s abdominal cavity is one of several ARS microscopy images changing what we know about how mites damage honey bees.

Research by scientists at the Agricultural Research Service (ARS) and the University of Maryland released today sheds new light — and reverses decades of scientific dogma — regarding a honey bee pest (Varroa destructor) that is considered the greatest single driver of the global honey bee colony losses. Managed honey bee colonies add at least $15 billion to the value of U.S. agriculture each year through increased yields and superior quality harvests.

The microscopy images are part of a major study showing that the Varroa mite (Varroa destructor) feeds on the honey bee’s fat body tissue (an organ similar to the human liver) rather than on its “blood,” (or hemolymph). This discovery holds broad implications for controlling the pest in honey bee colonies.

The study was published on-line Jan. 15 and in today’s print edition of the Proceedings of the National Academy of Sciences. An image produced by the ARS Electron and Confocal Microscopy Unit in Beltsville, Maryland is on the cover of today’s journal.

Varroa mites have been widely thought to feed on the hemolymph, of honey bees (Apis mellifera) because of studies conducted in the 1970’s which used outdated technology. But today’s collaborative study, by University of Maryland and ARS researchers at the ARS Electron and Confocal Microscopy Unit, offers proof of the mite’s true feeding behavior. Through the use of electron microscopy, the researchers were able to locate feeding wounds on the bee caused by the mites, which were located directly above the bee’s fat body tissue. The images represent the first direct evidence that Varroa mites feed on adult bees, not just the larvae and pupae.

In addition, University of Maryland researchers conducted feeding studies and found that Varroa mites that were fed a diet of fat body tissue survived significantly longer and produced more eggs than mites fed hemolymph. The results show, mites fed a hemolymph-only diet were comparable to those that were starved. Thus, proving conclusively that the Varroa mite feeds primarily on the fat body consumed from bees.

The results are expected to help scientists develop more effective pesticides and other treatments to help bees cope with a mite known to spread at least five viruses. They also help explain why Varroa mites have such detrimental effects on honey bees, weakening their immune systems, and making it harder for them to store protein from pollen and survive through the winter.

The study was part of the Ph.D. thesis of Samuel D. Ramsey from the University of Maryland and was conducted in collaboration with ARS researchers and study co-authors Gary Bauchan, Connor Gulbronson, Joseph Mowery, and Ronald Ochoa.

The study can be found here.

The Agricultural Research Service is the U.S. Department of Agriculture’s chief scientific in-house research agency. Daily, ARS focuses on solutions to agricultural problems affecting America. Each dollar invested in agricultural research results in $20 of economic impact.

Catch The Buzz: Varroa mites feed on the fat bodies of honey bees

Also see: https://www.losangelescountybeekeepers.com/blog/2019/1/15/honey-bee-parasites-feed-on-fatty-organs-not-blood

Winter Losses Still Too High

CATCH THE BUZZ    By Kim Flottum   May 15, 2014

WASHINGTON, May 15, 2014—A yearly survey of beekeepers, released today, shows fewer colony losses occurred in the United States over the winter of 2013-2014 than in recent years, but beekeepers say losses remain higher than the level that they consider to be sustainable. According to survey results, total losses of managed honey bee colonies from all causes were 23.2 percent nationwide. That number is above the 18.9 percent level of loss that beekeepers say is acceptable for their economic sustainability, but is a marked improvement over the 30.5 percent loss reported for the winter of 2012-2013, and over the eight-year average loss of 29.6 percent.

“Pollinators, such as bees, birds and other insects are essential partners for farmers and ranchers and help produce much of our food supply. Healthy pollinator populations are critical to the continued economic well-being of agricultural producers,” said Agriculture Secretary Tom Vilsack. “While we’re glad to see improvement this year, losses are still too high and there is still much more work to be done to stabilize bee populations.”

“Yearly fluctuations in the rate of losses like these only demonstrate how complicated the whole issue of honey bee heath has become, with factors such as viruses and other pathogens, parasites like varroa mites, problems of nutrition from lack of diversity in pollen sources, and even sublethal effects of pesticides combining to weaken and kill bee colonies,” said Jeff Pettis, co-author of the survey and research leader of the Agricultural Research Service (ARS) Bee Research Laboratory in Beltsville, Maryland. ARS is USDA’s chief intramural scientific research agency.

There is no way to tell why the bees did better this year, according to both Pettis and Dennis vanEngelsdorp, a University of Maryland assistant professor who is the leader of the survey and director of the Bee Informed Partnership. Although the survey, conducted by the U.S. Department of Agriculture and the University of Maryland Bee Informed Partnership shows improvement, losses remain above the level that beekeepers consider to be economically sustainable. This year, almost two-thirds of the beekeepers responding reported losses greater than the 18.9 percent threshold.

More than three-fourths of the world’s flowering plants rely on pollinators, such as bees, to reproduce, meaning pollinators help produce one out of every three bites of food Americans eat. The winter losses survey covers the period from October 2013 through April 2014. About 7,200 beekeepers responded to the voluntary survey.

The U.S. Department of Agriculture (USDA) also announced today that it will hold a summit this Fall aimed at addressing the nutrition and forage needs of pollinators. The summit will take place in Washington D.C. on October 20-21 and will be attended by a consortium of public, private, and non-governmental organizations. Attendees will discuss the most recent research related to pollinator loss and work to identify solutions.

Also today, USDA launched the People’s Garden Apiary bee cam at the USDA headquarters in Washington, D.C. as an additional effort to increase public awareness about the reduction of bee populations and to inform Americans about actions they can take to support the recovery of pollinator populations. The USDA “Bee Watch” website (www.USDA.gov/Beewatch) will broadcast honey bee hive activity live over the Internet 24 hours per day, 7 days per week. Created in 2010, the People’s Garden Apiary is home to two beehives. The bees are Italian queens, the most common bee stock and the same used in many honey bee colonies throughout the United States.

In March of 2014, Secretary Vilsack created a Pollinator Working Group, under the leadership of Deputy Secretary Krysta Harden, to better coordinate efforts, leverage resources, and increase focus on pollinator issues across USDA agencies. USDA personnel from ten Department agencies (ARS), National Institute of Food and Agriculture (NIFA), Farm Services Agency (FSA), Natural Resources Conservation Service (NRCS), Animal and Plant Health Inspection Service (APHIS), Economic Research Service (ERS), Forest Service (FS), Agricultural Marketing Service (AMS), Risk Management Agency (RMA) and Rural Development (RD) meet regularly to coordinate and evaluate efforts as USDA strives toward improving pollinator health and ensuring our pollinators continuing contributions to our nation’s environment and food security.

Earlier this year, USDA made $3 million available to help agriculture producers in five states (North Dakota, South Dakota, Minnesota, Wisconsin, and Michigan) provide floral forage habitats to benefit pollinating species on working lands. The Honey Bee Pollinator Effort is intended to encourage farmers and ranchers to grow alfalfa, clover and other flowering habitat for bees and other pollinators.

Recognizing the importance of pollinators on the health of the rural economy and the Nation’s food supply, the President’s FY2015 Budget proposes the creation of 3 new Innovation Institutes including one on Pollination and Pollinator Health (PPH). The budget requests up to $5 million a year over five years to be allocated for research to combat pollinator decline and colony collapse disorder. If established, the PPH will support the activities already identified in the joint USDA-Environmental Protection Agency action plan and build on current pollinator research and extension projects.

A complete analysis of the bee survey data will be published later this year. The summary of the analysis is at http://beeinformed.org/results-categories/winter-loss-2013-2014/.

Read at:  http://home.ezezine.com/1636/1636-2014.05.15.12.52.archive.html

This message brought to us by CATCH THE BUZZ: Kim Flottom,  Bee Culture, The Magazine Of American Beekeeping, published by the A.I. Root Company. Twitter.FacebookBee Culture’s Blog.