Honey Bee Lab News
Do you need antibiotics for Foulbrood control? The Food and Drug Administration’s new Veterinary Feed Directive (VFD) came in to effect on January 1, 2017, which means that beekeepers must obtain a prescription or VFD from a licensed veterinarian to purchase the antibiotic medications i.e. Tylosin (Tylan), Oxytetracycline (Terramycin) and Lincomycin (Lincomix) for controlling American foulbrood (AFB) and European foulbrood (EFB) diseases in their colonies. Beekeepers can no longer purchase these medication over-the-counter. If you need antibiotics for foulbrood control, please contact your local veterinarian for a prescription/VFD. If your local veterinarian needs assistance in diagnosing these bacterial diseases for providing a prescription, please ask them to contact us:
Dr. Ramesh Sagili
Dr. Andony Melathopoulos
Your veterinarian may also access our website (honeybeelab.oregonstate.edu) for more information on how to diagnose foulbrood diseases. For more details on Veterinary Feed Directive please access the following links:
Protecting bees from pesticides just got easier with the release by Oregon State University of a smartphone app that farmers and beekeepers can use to consult a publication when they’re out in the field.
Hope all of you had a relatively successful bee year with strong hives and significant honey production, and have prepared your hives for successful overwintering. I just wanted to take this opportunity to alert / caution you about possibility of high mite populations in the colonies this year due to an unusually long bee season. As you all are aware we had a long bee season this year (at least in the Willamette Valley) as a result of warm weather that prevailed for almost more than 7 months. Longer brood cycle (abundance of larvae) usually results in higher mite populations, as the mites get a greater opportunity to breed and increase their populations relative to bees. Most of you might agree that this year was a year with longest brood cycle seen in the recent past (I have been in Oregon only for the past 6.5 years, so can’t go beyond that number). It has been reported that mite populations could increase exponentially (up to about 50 fold increase) in years when the brood is present in colonies almost round the year (Martin 1998).
The economic threshold to treat Varroa mites in general for temperate areas is considered to be about 3% or higher in fall, but as economic threshold depends on several factors it is not ideal to always rely on this magic number. In Oregon during the past six years we have documented mite intensities ranging between 3% and 5% in Fall (August sampling). We observed significantly higher mite intensities this year (2015). The average mite intensity observed in backyard beekeeper colonies was 7%, whereas average mite intensity documented in commercial beekeeper colonies was about 3%. In few backyard beekeeper colonies we observed mite intensities as high as 32%, which is alarming.
If you treated your colonies for Varroa on time during July or August then probably you may have your mite populations under control, but still I urge you to monitor mites one more time before overwintering to make sure that the treatments that you used were effective and your current mite populations are not at damaging levels. If your mite levels are still high then please consider using an oxalic acid treatment if feasible when there is no brood (possibly during November).
If you did not use any Varroa mite treatments yet, then please assess the mite populations using alcohol wash or powdered sugar method as soon as possible and consider treating your hives with oxalic acid when there is no brood in the colonies. Oxalic acid was recently approved by EPA and is available from the bee supplier Brushy Mountain Bee Farm (http://www.brushymountainbeefarm.com/?gclid=CLzrqIrB98cCFUiEfgods-gJ6w).
Following are some consequences of inadequate or no Varroa mite control this fall:
- Bee population may decline significantly or the colonies might totally collapse.
- Colonies that survive the winter will start upcoming year / season with higher mite loads and hence could reach damaging levels soon by late spring or summer.
- High mite infested colonies may contribute to higher mite drifting via robbing bees to other beekeeper colonies and your existing healthy colonies, as your mite infested dead colonies may be robbed by other strong colonies and aid in greater mite dispersal.
Also, please continue feeding protein to your colonies if pollen stores are not adequate in the colonies. Protein feeding not only helps with brood rearing, but also helps boost the immune system of bees. We have observed colonies to consume protein until October 25 in the Willamette Valley and few other locations in Oregon when the weather is still OK (temperatures around 55 to 60° F).
Following is a question relevant to Varroa mite biology that an Oregon beekeeper asked me few months ago.
Question: How many days is the female Varroa mite outside of the capped brood before it re-enters another cell for reproduction? Do the young female mites that emerge along with the new bees also take the same amount of time to re-enter another larval cell for reproduction?
Answer: The time a female Varroa takes to re-enter (re-infest) a new cell depends on the availability of older larva (ready to be capped) to enter, and also on the number of bees in the hive at that point of time. One study showed that on average female mites take about 4 to 6 days to re-infest new larval cells. In a lab study, female mites that were artificially reintroduced into new cells with appropriate aged larvae (ready to be capped) immediately after emergence from a cell were able to reproduce successfully without any problems. Young female mites that emerge along with the foundress mite (parent mite) need time to achieve full maturity and hence may take a little more time to enter a cell for reproduction than the parent mite. Research pertaining to these new young mites is scarce, hence providing an average time for infestation is difficult.
Oregon State University
The solution to a huge problem may be hiding in the minutia of labs like this one at Oregon State University, where researchers examine the period-size brains of honey bees, test their blood and grind their guts for inspection under a microscope.
They’re looking for signs of parasites, viruses or nutritional lapses that may help explain colony collapse disorder.
Ramesh Sagili, who leads the OSU research effort, believes there is no single “smoking gun” cause of CCD. Instead, he and most other researchers say a combination of factors is most likely to blame.
More than one in five commercial honeybee hives in Oregon did not survive last winter, continuing a financially challenging trend for professional beekeepers.
Between Oct. 1 and March 31, Oregon beekeepers reported a 21.1 percent loss in colonies of the crucial crop pollinators, according to a survey by Oregon State University. The latest figures are a slight improvement over the state's average annual loss of 22 percent over the past six years.
Several highly publicized bee die-offs have increased concern for the health of Oregon's bee populations, prompting investigations and the establishment of a legislative task force to examine pesticide use and improve pollinator habitat in the state.
A collapse in bee population could destabilize food supplies, as about a third of all the food we eat is dependent on bee pollination. In Oregon, commercial and wild bees provide an estimated $600 million in annual agricultural value.
Fewer honeybee colonies died last winter, but mortality rates remain a cause for concern, according to a national survey released earlier this month.
Beekeepers across America reported 23.2 percent of their colonies died between Oct. 1 and March 31 in a survey conducted jointly by the Bee Informed Partnership, the Apiary Inspectors of America and the U.S. Department of Agriculture. Since the winter of 2007-08, the die-off rate has been below 29 percent only one other year, in 2011-12, when it was 21.9 percent.
Ideally, only 10 percent of colonies would die off during a given winter, said Ramesh Sagili, an apiculturist, or bee expert, with Oregon State University. But the large die-offs of recent years have caused beekeepers to adjust their expectations upwards in terms of mortality, he said. Compared to 30 percent, a die-off rate of 22 percent, which is where Oregon’s colony mortality rate has hovered in recent years, seems reasonable, he said.
OSU master beekeeper program promotes innovation, collaboration on honeybee education.
We have never asked bees to do more work than we are asking them to do now for society, according to Joe Taylor, an undergraduate researcher in the Oregon State University Honey Bee Lab.
This is why bees are a crucial part of our world.
Taylor, a senior in natural resources in the Department of Forestry, has a passion for bees. This passion has inspired Taylor’s research on the nutrition of bees.
A Portland-based renewable products company plans to back honey bee research through an agreement with Oregon State University.
Bambu will work with the school’s Honey Bee Lab, which analyzes honey bee health and nutrition, examines pollination efficiency of honey bee colonies and works with the Oregon Master Beekeeper Program.
Oregon State University is hot on the trail of improving the lot of honeybees, an interest triggered by declining populations of the insect vital to agriculture.
OSU has a new tool for the industry in the Pacific Northwest to reduce the impact of pesticides on bees.
A revised publication is available in the wake of an estimated loss of 50,000 bees in a Wilsonville parking lot in mid-2013. The Oregon Department of Agriculture confirmed that the deaths were related to an application of a pesticide to city trees to prevent aphids, a problem not linked to agriculture.
However, the episode has resulted in ODA slapping a six-month restriction on use of 18 insecticides containing dinotefuran.
An Oregon State University bee expert said that it is wrong to blame colony collapse disorder on neonicotinoid insecticides.
Ramesh Sagili, an assistant professor in the Department of Horticulture at OSU, said that exposure to neonicotinoids and other pesticides is just one of many factors contributing to the recent decline in bee populations.
As the worldwide population of honey bees continues to decline, the Oregon State University Extension Service and partners have updated a tool for Pacific Northwest growers and beekeepers to reduce the impacts of pesticides on bees.
The revision of OSU Extension's publication appears after an estimated 50,000 bumble bees died in a Wilsonville parking lot in June. The Oregon Department of Agriculture confirmed in a June 21 statement that the bee deaths were directly related to a pesticide application on linden trees conducted to control aphids. The episode prompted the ODA to issue a six-month restriction on 18 insecticides containing the active ingredient dinotefuran.
OSU researchers are investigating the effects of broad-spectrum neonicotinoids, such as dinotefuran, on native bees. The work is in progress, according to Ramesh Sagili, an OSU honeybee specialist.