Sentinel Apiary Program Monthly Memo: October Issue

Original photo of mite: Julia Stoess

Welcome back to yet another Sentinel Apiaries update. We’re coming to you in the spookiest month of the year with some pretty scary stuff: mites, mites and more mites! I spent an embarrassing amount of time in photoshop to drive this point home (see right). As we always do in September, we saw a pretty significant jump in mite loads last month. Over 50% of states were above treatment threshold. You can see a lot less yellow (below threshold states) on our Varroa heat map below.

Mite loads in Sentinel apiaries were much higher this September than last year (see below). If you have yet to check or treat for mites, now is the critical period before winter sets in. You want your mite loads to be as low as possible before overwintering, because those winter bees have to live until spring and may not make it if they’re sharing their space with these unwelcome guests.

Compare monthly average mite loads between this year’s Sentinel apiaries (red), last year’s Sentinel apiaries (blue), and the National Honey Bee Disease Survey average (gray).

As for this month’s Sentinel Superlatives, a big shout out to the following:

Congratulations to Washington for having the lowest average mite load in September with only 0.77 mites/100 bees. Well done keeping those loads in check Washington!

The state with the biggest bees was Illinois yet again. This is their third month winning the award for bulkiest bees with 0.187 grams per bee. Let’s see if anyone can dethrone them this month!

The state with the most drones total was Michigan with a whopping 595 drones. That number should start to taper off soon as their colonies kick the free loading boys out before winter.

The state with the most drones per sample was New York for the second month running with 18 drones per sample.

That’s it for this month’s update. Check back next month for our final memo of the year where we’ll recap Varroa and Nosema loads, other colony health metrics, and do full year superlatives!


Sentinel Apiary Program Monthly Memo: September Issue

Author (Kelly Kulhanek) presenting the Sentinel Apiary Program at Apimondia.

Hello Beekeepers, we’re back with the September Sentinel Apiary update one day late but hopefully not a dollar short! It’s been a very busy month full of monitoring and treating for mites, plus a trip to Montreal for the Apimondia world beekeeping conference. It was such a blast to see so many Sentinel beekeepers and BIP supporters north of the border and to present the program at the citizen science session.

Of course, while the beekeeper is away, the bees (and mites) will play. Here’s what happened with Sentinel Apiaries in August (September update to come shortly).


Last month, 61 beekeepers submitted 330 samples from 25 states. We were very happy to see that mite loads only increased slightly between July and August. In 2018, we saw a bigger jump over this time period, and you can see that the National Average typically has a substantial increase. This means Sentinel beekeepers are remaining vigilant after that big jump we saw in July. Keep up the good work, and we’ll see how things look in September.

Monthly average Varroa loads for this year’s Sentinel (red), compared to last year’s (blue) and the APHIS national average (gray).

More northern states have started to exceed the suggested treatment threshold of 3 mites/100 bees including Maryland, Maine, New York, Oregon, New Jersey and Wisconsin. Check out Varroa heat map to see if your state is above threshold and get out there and monitor.


As for this month’s Sentinel Superlatives, a big shout out to the following:

Congratulations to Minnesota for having the lowest average mite load in August with only 0.63 mites/100 bees.

The state with the biggest bees was Illinois for the second month running with 0.197 grams per bee. They must be eating their Wheaties over there!

The state with the most drones total was Michigan with 207 drones. Note: this will likely always be Michigan as they have the most Sentinel Apiaries in one state: 10.

The state with the most drones per sample was New York with 12 drones per sample. That’s a lot for this late in the season!


We also had a big jump in reported honey harvest last month, with a total of 5,197 lbs of honey harvested from Sentinel Apiaries. New Jersey reported the most honey harvested with a whopping 1,950 lbs. We’ll be back next month to see if anyone topped that in September! That’s all for this month’s update. Thanks for reading and we’ll see you next time.


Sentinel Apiary Monthly Memo: August Issue

We’re back again with another monthly update from the Sentinel Apiary Program! Let’s take a look at what’s been going on with mites, drones, honey, and more over the past month.

Throughout the month of July, Sentinel participants submitted 378 samples from 71 apiaries across 27 states! July finally showed us a big increase in mite loads, with the average Sentinel apiary now at the treatment threshold of 3 mites/100 bees. This July Sentinel apiary mite loads are higher than the historic national average, and much higher than the mite loads from last year’s Sentinel apiaries. This could mean we’re having especially high Varroa pressure this year, so if you have yet to check your colonies for mites, now is the time!

Monthly average mite loads for 2019 Sentinel apiaries compared to the historical national average, and 2018 Sentinel apiaries.

The state that had the lowest mite load in July was Colorado with an average of 0.22 mites/100 bees. Way to go Colorado! Over 50% (n=14) of states exceeded the 3 mites/100 bees threshold in July. The trend of higher mite loads in southern states is holding strong, with most southern states well past the threshold of 3 mites/100 bees. Northern states are also starting to creep up and will likely exceed that threshold in August. Check out our interactive Varroa map to see how your state is faring.


As for our July superlatives, congratulations to the following!

The state with the biggest bees: Illinois with 0.189 grams/bee.

The state with the most drones total: Michigan with 259 drones.

The state with the most drones per sample: New Jersey with 131 drones total, over 16 drones per sample!


University of Maryland apiary manager Andrew Garavito loads full honey supers onto our truck.

We also started to get Sentinel participants reporting honey harvested in July. A total of 12 beekeepers reported they harvested a total of 1,070 lbs of honey from Sentinel colonies. The state that reported the most honey harvested in July was Arizona. Let’s see if anyone can beat them in August!


That’s all for this month’s update. If you’re a Sentinel participant and have ideas about what you’d like to see in future updates, please let us know. We’ll be back next month to see how everyone looks as we approach fall!


Sentinel Apiary Monthly Memo: July Issue

We’re here to help you beat the heat with your second monthly Sentinel Monthly Memo of the year. It has been hotter than Hades out there, so hopefully you and your bees are keeping cool. We’re another month into the 2019 Sentinel Apiary Program, and here’s what we’re seeing.

In the month of June, we received a record 417 samples from 70 Sentinel Apiaries in 28 states. To put that into perspective, that’s over 125,000 bees, enough to comprise 2-3 full colonies. Our undergraduate lab technicians are certainly being put to good use!

Congratulations to the state with the lowest June mite load: New Hampshire with 0 mites! Mite loads continue to be higher in the South, with North Carolina, Georgia, Louisiana, Alabama, and Arizona above treatment threshold. Be sure to check out our interactive Varroa map to see mite loads at the county level. For the first two months of the program, Sentinel Apiaries have had lower average mite loads than the National Average (via APHIS NHBDS). We hope to continue this trend for the rest of the season!

Sentinel Apiary average mite loads (red) compared to the National Average (gray).

A couple of other fun superlatives we will begin awarding each month: the state with biggest bees was also New Hampshire with an average of 0.196 grams per bee. For context, the average bee weight was 0.173 grams.

The state that submitted the most samples was Michigan with a whopping 68 samples.

The state that submitted the most drones total was also Michigan with 369 drones. The state with the most drones per sample was New York with an average of 24 drones per sample. Sorry boys!

It’s also peak honey flow season, and we can’t wait to see how much sweet stuff our Sentinel participants pull in. Be sure to check out our hive scale map to see how your state is stacking up in honey production! And remember, as soon as you get those supers off you should monitor and apply a Varroa treatment if needed. Be careful to choose a treatment with a generous temperature threshold as it’s too hot for a few of the most popular chemicals. The Honey Bee Health Coalition has great resources to help you choose a safe product.

Check out our interactive hive scale map at

That’s all for this month, we’ll be back in August with another update. Stay cool out there and Happy Beekeeping!


Sentinel Apiary Monthly Memo: June Issue


I don’t know about you, but my back hurts, which must mean the peak beekeeping season is officially well underway. The honey is flowing and supers are filling up. Do you know what your mite loads are? If not, Sentinel Apiaries are here to help. Sentinel Apiary participants sample 4 or 8 colonies for Varroa every month during the peak beekeeping season. This year marks the largest year of the Sentinel Apiary Program to date with 102 registered Sentinel Apiaries! If there’s a Sentinel Apiary near you, check their mite loads at This can help show you what mites are doing in your neighborhood.  Now that the first month of the program is complete, we’d like to begin a series of monthly Sentinel updates to share results with the BIP community.

Throughout the month of May, over 330 Sentinel Varroa and Nosema samples were processed by our diagnostics lab! Apiaries were sampled in 26 states across the country. Typically, the trend is that mite loads increase faster in the south than they do in the north. This makes sense because the warm southern climate allows colonies to brood up earlier, and mites depend on capped brood to reproduce. This year’s Sentinel Apiaries have shown just this, with May mite loads higher in the south than the north. So far, of the participating states, Arizona, Texas, Alabama, Georgia, Florida and North Carolina have exceeded an average of 2 mites/100 bees in Sentinel Apiaries.. So if you’re in the south, be sure to monitor next time your colonies are super free and get a treatment in if you need one.

Figure 1. Map of Sentinel mite loads available at Varroa loads are also displayed at the county level.

All other participating states are still well below threshold at an average of 0-2 mites. A big congratulations to Wisconsin for having this month’s lowest mite load at 0.09 mites/100 bees! This is great news for northern beekeepers, who have seen colder and wetter weather than typical, but be sure to still monitor if you’re planning on adding supers soon. It’s important to make sure your mite levels are as low as possible if it’s going to be a while before you get back down to the brood nest to sample. It’s only a matter of time until mite loads rise throughout the country.

Figure 2. University of Arkansas Apiculture Instructor Jon Zawislak prepares for flooding by propping colonies up on cinderblocks. Photo from University of Arkansas, Jon Zawislak.

Another observation from early Sentinel samples is that weather has been anything but normal. Sentinel participants report on whether their climate has been atypical, and many participants cite heavy rains and abnormal temperatures as negatively impacting their colonies. There has been substantial rain and flooding throughout much of the Midwest and plains regions. Beekeepers are having trouble getting queens well mated, as well as producing honey since there have been so few days with flyable weather. It’s been a rough start to the year for many, but everyone is hoping things will calm down soon in time for the last couple months of summer.

We’re just getting started and we would love to hear from you. As the season progresses, we’ll be sharing some interesting data in these monthly blogs and hope to have some Sentinel participants share how their monthly monitoring is changing how they manage their colonies. Get ready, hold on and take care of your back!



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!


2016 Sentinel Apiary Program Results

With the help of beekeepers all over the country, we have successfully completed our second year of the Sentinel Apiary Program! In 2016, 28 beekeepers from 16 states worked with us. Together we:

  • Sampled and monitored the health of 289 colonies
  • Processed 1,229 samples for Varroa and Nosema
  • Shared data from 32 hive scales
  • Collaborated with our beekeeping neighbors to improve colony health in our regions
A map of our 2016 Sentinel Apiary Program participants.

After compiling over six months of Varroa, Nosema, and colony inspection data, we are excited to share our results (see the complete 2016 Summary Report Here). Below you can compare our Sentinel Apiary Participant’s average monthly Varroa levels to the APHIS National Honey Bee Survey’s national monthly average. We were thrilled to see that Sentinel Participants had significantly lower mites/100 bees in the key winter prep months of September and October; however, more work needs to be done as those samples were still over threshold.

Monthly average Varroa levels for 2016 Sentinel Participants compared to the APHIS national average.


Our live Varroa heat map can be viewed HERE.

Last year we also developed a new public Sentinel Apiary Varroa heat map. This is the first consolidation of Varroa numbers at the county level! Thanks to Sentinel Apiary Participants, we are now able to keep careful watch over our region, state, and some counties to be prepared for any spikes in Varroa infestations. The more counties we have participate, the more useful this map will be for beekeepers across the nation!

Sentinel Apiaries also include hive scale data collection, and last year we grew to have more scales on the BIP scale map than ever before. Hive scale data can help alert beekeepers when to add or remove supers, when to feed, or if a colony has potentially swarmed. Data collected by Sentinel Apiaries and shared on our public map can thus help not only Sentinel Participants, but all beekeepers in the surrounding region.

Our live Hive Scale Map can be viewed HERE.







Overview of the Sentinel Apiary Program

Sentinel Apiaries monitor honey bee health in real-time using hive scales to track colony weight gain or loss, and monthly disease assessments of Varroa and Nosema loads. The scale data is automatically transmitted to our servers and the patterns of nectar flow mapped.

The goal is to collect enough information so that Sentinel Apiaries become an early warning system to alert beekeepers of potential problems due to increases in Varroa/Nosema or changes in colony weight. One Sentinel Apiary in a county can thus empower all beekeepers in that area to take early action to protect their colonies.

This is a great opportunity for individual beekeepers and beekeeping organizations alike! As an individual you will gather in-depth knowledge about the health or your colonies and apiary. As an organization, sampling Sentinel Hives offers a unique opportunity to train new beekeepers and to have interactive field days. You will be able to make more informed management decisions, as well as share information with beekeepers in your region to encourage collaborative colony monitoring and management.

This year, we are pleased to offer two new cooperating hive scale vendors, making the Program more affordable than ever! Plus, on a limited first-come first-serve basis, we are able to offer $300 subsidy towards the purchase of a scale for the Program.

Participate in the Sentinel Apiary Project

We are now accepting applications for the 2017 Sentinel Apiary Program. With data collected from Disease Load Monitoring and a Hive Scale, you will gain information you need to take your beekeeping to the next level.

If you are a beekeeping association or an individual beekeeper who is interested in joining our Sentinel Apiary Program, please click the “Sign Up” button below and we will contact you to provide more details about the Sentinel Hives.

Sign up for Sentinel Apiaries



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