It’s Cold (and Wet) Out There


This dead forager was one of the few bees I saw on an almond blossom during the early bloom period. She likely succumbed to hypothermia after spending the night away from the colony (note the damp matted hairs).

I don’t know what the groundhog did or saw this year, but according to the calendar it’s still winter. The first day of spring is still a month away. If you’re a pollinator or grower of almonds, you’re hoping weather conditions up and down the central valley of California become more favorable for flight activity than they have been. I recently returned from 2 weeks of inspecting and sampling colonies where conditions were cold, wet, and windy. These conditions delayed onset and slowed progression of the almond bloom and are forecast to continue. Frequent updates on the progression of bloom and conditions for flight are available from Blue Diamond.


The abundance of water and scarcity of flowers in this orchard near Chowchilla, CA characterized the first half of February in most of the central valley.
Muddy conditions prevailed as the last of the colonies were being set.

In addition to the revenue from pollination fees, beekeepers also count on floral resources provided by the 1,000,000+ acres of almond trees that stretch roughly from Chico in the north to Bakersfield in the south. Many colonies get stimulated with feed prior to bloom to boost brood production and size.  If there is not a smooth transition from supplemental feed to forage, because of inclement weather, colony growth can be hindered. If cool and wet conditions persist, many beekeepers may need to resume supplemental feeding to avoid starvation. The persistent wet conditions can also be problematic for growers and lead to increased application of fungicides which may be perilous to bee health.


Aside from the biotic implications for the bees, there are also practical difficulties for beekeepers. In the last few days there have been an abundance of photos and videos online of colonies submerged in orchards or swept away by flooding rivers. Some beekeepers have had truckloads of colonies get snowed in on mountain passes into the valley where wintery conditions have closed highways. At the very least, getting in and out of orchards to deliver or work colonies has been a muddy mess. With so much of the national herd sitting in one location, the implications of the current and near future conditions in the region may ripple across the country this season as colonies are dispersed post-pollination.


Spring Hygienic Testing and California Hygienic Score Trends

This spring we will start Hygienic testing Queen breeders’ colonies. This is my favorite type of testing for beekeepers because we get to look at the best performing colonies in the entire operation. The beekeeper we  work with often selects the best hives throughout the year for performance and marks them, then in the spring the final selections are made from spring build up and how well the colonies-maintained size over the winter. It is best if the colonies are all in the same yard because it is easier to go through colonies quickly. Sometimes we test in almonds and have to move from pallet to pallet throughout the orchard. We will usually test between 25-100+ hives depending on the size of operation or the number of breeders a queen producer will want to use for their breeding program.

Here is a colony being tested, there is a 3 inch PVC pipe that is pressed into the sealed brood with liquid nitrogen freeze-killing the selected brood area.

Over the past seven years I have seen great improvements on hygienic scores overall. Beekeepers that have been selecting for the hygienic traits have improved little by little each year at selecting more colonies that test well. This fall I worked with Nathalie Steinhauer our BIP statistician to look at how the hygienic scores have been improving in 11 different operations. The graph below shows that beekeepers that have been selecting for the hygienic traits and testing for them have been improving each year. I feel that hygienic scores throughout colonies selected for the test amongst breeders has been more consistent due to our work assisting them select more hygienic breeders and drone mothers. I noticed new beekeepers to the program that haven’t been selecting for the traits don’t have as much uniformity throughout the selected colonies and don’t test as high overall. Although, the new beekeepers to the program that have been selecting for the traits the past few years have improved their hygienic stock and overall consistency. It amazed me to see improvements so fast, within 3 years of selection there were more high performing colonies than at the start.

Hygienic Score Trends for CA beekeepers


Here is a colony that tested very well with 100 percent uncapped and removed brood in freeze-killed cells.

I have made many observations about the hygienic trait and saw first-hand why this should be an important tool for queen breeders and producers. Colonies with EFB observed were barely detectable because the bees were removing the sick larvae so fast. I also noted that colonies that were hygienic remove a lot of chalkbrood, but chalkbrood is harder to remove so colonies were not as cleaned out as seen with hygienic colonies that had EFB. One-way beekeepers spot hygienic colonies are by observing ones that chew newspaper from a split fast or a glycerin oxalic acid shop towel removed quickly. I don’t see as much Sacbrood Virus (SBV) here in California as I saw inspecting hives in Pennsylvania and in North Dakota, I often wonder if it is because the hygienic bees remove SBV larvae quickly? In all I feel the hygienic traits are necessary to help colonies combat diseases and other brood maladies, I look forward to the future of tests to see how these scores may change and perhaps correlate with other factors such as varroa loads.

A colony that scored ok on the hygienic test, you can see some of what is left from the bees uncapping and removing brood. You can notice there are some pupa without heads, this patch of brood had some brood that was too young to test. We try to find patches of brood with a developed head.

Not much, but not nothing

What are your bees doing right now? If you’re in a northern location like me in Michigan the answer for most of the period between November and February may be not much. . .  but they aren’t doing nothing. They are dormant but they aren’t hibernating. During the period of winter dormancy the bees will cluster together to conserve the heat generated by individual bees vibrating their flight muscles. The bees aren’t attempting to heat the entire volume of the hive like we would heat a house, instead their shivering behavior just maintains the necessary temperature of the cluster itself. This behavior allows the colony to survive very cold external temperatures and generate enough heat to begin brood rearing which typically starts shortly after the winter solstice.

When I mention ‘my bees’ I’m referring to the Sentinel Apiary I manage in Leelanau County. I was out in mid-December on a 40ish degree day to take advantage of their broodless period and apply an Oxalic acid dribble as part of my Varroa mite management strategy. This brief cracking of the hives provided a chance to assess cluster size and position as well as evaluate stores. It’s not optimal to be opening hives this time of year and you certainly shouldn’t be pulling frames but I deliberately picked a fairly mild day with minimal wind for the time of year. Overall the colony was open for about 20 seconds and I was able to assess the condition and apply the Oxalic Acid with minimum disturbance.

I was relatively pleased with the size of cluster shown below, a little bigger would be ideal but they appear to be of adequate size to have a strong chance of surviving winter. They happened to be vertically centered near the top bars of the bottom box (purple) so the view is of the roughly spherical cluster split at the equator. The middle box (yellow tipped on end) had very good weight to it and the top box (blue with inner cover and moisture board remaining in place) was a box full of capped honey. This should be plenty of honey to get them through to April when the first dribble of nectar appears and it is starting to get warm enough for them to take liquid feed.

Bees clustered during winter dormancy

If I had found them primarily in the middle box or up into the top at this early stage of winter I would be more concerned about their stores and be making plans to get some fondant on as an emergency feed to get them through the later stages of winter but they still have plenty of food to eat their way up into. If you find your bees are high in the hive early in winter or getting light while spring nectar or syrup is still a ways off providing the colony with fondant is your best chance to avert starvation. Fondant is relatively easy to make, a couple recipes are available here and here.  It’s certainly isn’t a sure thing that this colony survives the winter but I’m fairly optimistic given the aggressive Varroa control through the season to keep mites and viruses in check and adequate food stores above these bees.


2018 Sentinel Apiary Program Results

The fourth year of the Sentinel Apiary Program was another great success! The program included 64 beekeepers sampling 418 colonies, for a total of 1,901 samples!

You can view the whole 2018 Summary Report here.



We are very excited to share that 2018 Sentinel Participants had significantly lower Varroa loads than the historical national average!






Our Hive Scale Map also underwent extensive remodeling this year, and now includes Varroa data as well as showing a net weight gain or loss per state over the past week to provide even more real time context.





With three years of extensive colony health data now collected, we are finally ready to begin asking some exciting questions. A couple of innovative ways we are using Sentinel data are:

Preliminary results of experiments on inter-apiary mite transmission. Red arrows indicate distance and direction traveled by bees from crashing colonies, potentially bringing mites to new apiaries.


Investigation of inter-apiary Varroa transmission. Sentinel data revealed rapid increases in Varroa populations that cannot be explained by normal mite reproduction, indicating a possible outside source of mites. This has led us to begin investigating the extent to which Varroa from highly infested/crashing colonies spread to nearby apiaries across the landscape.





Correlation of internal physical symptoms to mortality using historical Sentinel samples. We save~10% of all Sentinel samples as a historical record, and recently a PhD student in our lab, Anthony Nearman, has made exciting headway in correlating internal abnormalities (such a sting gland swelling, see image) in these bees to colony mortality. This could pave the way for a new method of colony sampling to better predict mortality.

Comparison of a swollen sting gland (right) to a healthy sting gland (left). Internal symptoms like these seem to be good predictors of colony mortality.


Example of what the NASA-Developed tool will look like: allowing us to determine a radius around Sentinel Apiaries to look at surrounding landscape factors.

Collaboration with NASA-DEVELOP to investigate landscape effects on Sentinel colony health using NASA-Earth satellite imagery. This summer we had the amazing opportunity to work with NASA to develop a tool which can intake information about your Sentinel Apiary and show us a variety of landscape factors around it such as precipitation, soil moisture, and land cover. This will allow us to make correlations between the landscape, colony health, and how the effectiveness of management practices varies across space. A video about this work can be found here.

We are already recruiting for the 2019 season! If you would like to provide invaluable data while taking the best care of your colonies, learn more and sign up here!


Eyes in the Sky: Mapping Bee Health

The original BIP drone, nicknamed “Eve”, in Texas. Sampling colonies and pairing aerial imagery with the diagnostic data may provide insights into how health shifts through an apiary.

Among the most exciting aspects of BIP’s work is the wealth of data collected for years on honey bee health. This impressive, growing database is keeping a pulse on the health of American bees. With an abundance of information, and growing team to analyze it, we’ve begun to explore new methods to monitor and detect trends and to optimize sampling. It is exciting to be part of team that is open and enthusiast to embrace innovative technology and new interdisciplinary approaches to examine questions around honey bee health.

My personal background, for example, is as a geographer. The BIP team has encouraged my interest in applying spatial analysis to the incredible honey bee health data base. We’ve been working with drones (no, not male bees!) to collect aerial imagery of apiaries to examine the potential effects of colony positionality on disease susceptibility. This is just the beginning of using these data in machine learning algorithms. We’ve also begun looking at the relationships between land cover, agricultural forage value, environmental factors, and colony survivorship.

With all of this, the core of our mission remains to give beekeepers actionable information about apiary management and colony health. We strive to communicate in a way that neither water-downs import nuances nor overwhelms with inaccessible language. We look forward to continue conducting cutting-edge research projects like these to help beekeepers better manage their apiaries. By donating to our 2018 fundraiser, you can sustain our work for years to come! Please DONATE NOW.


BIP Mobile Bee Diagnostic Lab

Our Bee Informed work trucks serve as virtual mobile bee labs, and are stocked with everything we need to take a variety of samples. On this particular day, the Pacific Northwest Tech Transfer Team was preparing to take virus samples in addition to the standard varroa/Nosema testing, as part of a longitudinal USDA study on bee viruses. Each individual bee will be tested (rather than the typical composite sample) to determine the type, variation and scope of viruses present. Numbered tags are stapled on each colony so they can be found again and longitudinally monitored over many months. The cardboard box contains a cooler full of dry ice that will be shipped overnight to the lab for virus processing. The 100-bee samples need to be frozen right away to prevent degradation of the virus replicates. Please help us continue to provide these specialized services and donate now to keep our mobile lab well stocked!



Was it enough?

An examination of debris on the bottom board shows a handful of dead Varroa mites after treatment. Photo credit – Dan Wyns, BIP Michigan Tech Team


One of the most critical aspects of maintaining healthy colonies is the control of Varroa mite levels. If you are a regular reader of these blogs, this will not be surprising to you. Visual inspection after applying a treatment may indicate a high mite drop but this may not be sufficient to determine if Varroa levels have been reduced to a satisfactory degree. One of the ways that BIP Tech Transfer Teams work with beekeepers is to quantify Varroa levels in order to determine the efficacy of a treatment and decide if further intervention is necessary. This level of vigilance can and should be part of every beekeepers’ management plan. The Tech Teams perform timely sampling and provide real-time, data-driven, decision power to improve colony health and these data help inform the data we share with the beekeeping community at our research site. PLEASE take a minute and donate now to our efforts. We want to help make you the best beekeeper you can be.


Emergency response team for crashing colonies

Tech-Transfer Teams provide third-party documentation of emergency events, such as acute pesticide poisoning, for beekeepers who request this service. The Northwest team responds to at least two emergency calls every year. BIP Tech Teams provide a complete colony health assessment during these calls to help find the underlying issue or at least rule out other possible contributing causes of colony loss. This includes sampling for Varroa mites, Nosema, tracheal mites, and viruses as well as pesticide analysis of dead bees, bee bread, fresh pollen, wax and honey. Sampling dead or dying colonies is difficult for everyone involved but knowing that there is a resource that beekeepers can call for a quick response is a comfort. Please donate to BIP to help keep this valuable service operational.

Northwest Tech Team member, Ellen Topitzhofer, samples freshly collected bee bread for pesticide testing. Photo credit: Carolyn Breece, Oregon State University.

Making a Difference

Over the past seven years working with BIP, I have witnessed, first hand, improvements on the quality of the hygienic behavior in honey bee stock coming out of the Northern California Queen Breeders. Of all the variety of samples we perform as BIP Tech Teams, hygienic testing is my favorite because it means I get to look at the best performing colonies in each of the operations we work with. Over the years, I have noticed a decrease in the severity of European foulbrood, Chalkbrood and Sacbrood virus due to our collaborative efforts with the beekeepers in the program who select for hygienic behavior traits. I noticed new participating beekeepers, who have not yet been selecting for the traits, do not have as much uniformity throughout their selected colonies and those do not test as high overall. But after a few years, these beekeepers are able to increase the amount of high performing colonies and have more uniform test results across the board. This leads me to believe that our sampling and testing efforts are paying off, resulting in stronger US stock and convinced that more beekeepers would benefits from this valued service. Please donate to the Bee Informed Partnership and help us continue to make a difference!

Elevated score (100%) on the hygienic test. Notice the bees have removed all of the frozen pupae in the course of a 24 hour period
Here is a low performing colony score to compare with, where the bees have not removed as many pupae during the same given time period.

Data-Driven Applications for Beekeepers

With the withdrawal of Fumagillin from the market, there has been renewed interest among queen producers and honey producers alike in finding ways to control Nosema infection in their bees. The Texas BIP team recently helped a beekeeper look at whether essential oil patties or a sprayed-on probiotic would help reduce the Nosema load of spring splits. 30 colonies (8-12 colonies per group) were sampled for Nosema at time of check-back (mid-April 2018) and randomly selected to be part of one of three groups: untreated control, essential oil, or probiotic. When Nosema loads were sampled again (mid-May 2018), the levels had gone down in all groups in accordance with the usual seasonal pattern. However, there was no significant difference seen between the treatments.

Results of a small case study evaluating the effects of essential oil patties and sprayed-on probiotic on spring Nosema levels in a TX operation

It is important to communicate non-conclusive results like these – as an antidote to the hype that often accompanies new products – and because it steers us toward testing the products in a different setting where they may actually work. Our ongoing sampling work with many operations puts us in a great position to collaborate with beekeepers on experiments, and to pursue questions that have immediate application among beekeepers. By donating today, you are enabling us to build on these strengths.


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