CAPPings – May/Jun 2021

May 14, 2021



I need to keep this message short and sweet, well, because the nectar flow is underway as is programming for the Clemson Apiculture and Pollinator Program.

First of all, I need to announce that I have moved my base of operations. My office is now located at the Pee Dee Research and Education Center in Florence, SC. This is a good move for many reasons. Baruch (in Georgetown), where I was located, will be hiring new researchers and is feeling growing pains, so I volunteered to move to provide space for the incoming hires. Pee Dee REC is a more agriculturally focused research station which will provide CAPP with more opportunities to collaborate with peers working with cropping systems that rely on insect pollinators and with other entomologists. Juang Chong (JC), the extension horticultural entomologist, Francis Reay-Jones, our Integrated Pest Management Program coordinator, and Matt Smith, the coordinator of the Sustainable Agriculture Research and Education program are all located there, and this move will facilitate more synergy among our programs. Also, there are plans to hire a vegetable entomologist and house that person at Pee Dee. I have already established a demonstration apiary there and have plans to install pollinator habitat research and demonstration plots at the facility. I also think that most of you (the beekeepers and pollinator conservationists) will find Florence to be a bit more accessible than Georgetown.

As for program updates, we have a number of things cooking at the moment. First, I will be conducting an in-service beekeeping training for Extension agents starting this month. This is a program that is long overdue and essential to the development of better beekeeping education programs statewide. Extension agents are phenomenal educators that work with a vast array of clients from homeowners to massive farming and forestry operations, from youth to retirees, and people working in almost every occupation and discipline. Improving the beekeeping knowledge of our agents builds capacity for our programs to reach beekeepers and the general public statewide to hopefully facilitate growing the beekeeping industry in SC and improve the general public’s awareness about the importance of beekeepers, honey bees, and pollinators in general. When I polled my colleagues about their interest in receiving apiculture training I was pleasantly surprised to receive a large response. This training involves 45 agents from across the state working in 4H, horticulture, agriculture, forestry/natural resources, and some administrative staff. This excites me as to the possibilities of growing and improving how we assist beekeepers statewide. For my military friends out there, I look at this program as being the first force multiplier in improving the effectiveness of the Clemson Apiculture and Pollinator Program.

We also just announced the first ever offering of a Basics of Entomology training for Master Gardeners and Master Naturalists. This seven-session training, which begins in June, will teach entomology fundamentals to the two groups of Extension volunteers that have the greatest impacts statewide. Master Gardeners and Master Naturalists serve as surrogates for Extension and log thousands of service hours every year as they conduct plant clinics at farmers markets, talks to garden clubs and civic groups, outdoor educational events, booths at fairs and festivals, and even some citizen science projects. By improving their understanding of insects and how to study and identify them, we hope to improve their ability to engage their communities in efforts such as pollinator conservation, proper pest control through integrated pest management, and appreciation for biodiversity and the ecosystem services insects provide. I knew that the training would be popular. Afterall, nothing is cooler than insects, but we were enthused when the training was filled in just hours after registration opened. Thankfully, we are already making plans to develop an ongoing entomology training program for both our Master Naturalists and Master Gardeners. Stay tuned if you are interested. We hope to expand the training beyond just the Master Gardener and Master Naturalist programs.

Last, we (Brad Cavin and I) are pleased to be able to assist the SC State Beekeepers Association with its return to in-person training at the summer conference in Charleston this July!!! We have been asked to set-up a bee yard at the conference to provide some hands-on field trainings as part of the conference agenda. We are working-out the details right now, but we look forward to providing opportunities for beekeepers at all experience levels to learn while in the bee yard. Some of the stations will feature Varroa mite biology and control, conducting inspections and reading frames, controlling small hive beetles, alternative hive systems, taking disease samples, queen rearing techniques, and more. The bee yard schedule will be posted with the conference agenda, so we hope everyone will come join us in the bee yard this July!

Kindest regards,
Ben Powell
Clemson Apiculture and Pollinator Program Coordinator






Well, as my generation might say, “It’s on like Donkey Kong!”

I can’t speak for everyone, but just about every beekeeper that I have talked to that has been at it for more than a few years has said the same thing. This year’s nectar flow has been one of the best we can remember. A mild, wet winter followed by a cool, dry spring with few interruptions by storms have created ideal conditions for nectar production and for honey bee foraging behavior.  Of course, many factors affect honey hoarding, so not every bee colony will experience the same amount of honey production. Forage availability, strength of colonies, weather, apiary conditions, pest and disease pressure, and other factors will affect the ability of a colony to store surplus honey, but statewide conditions have been favorable for a productive honey crop this spring. Let’s hope it continues.

Dish containing drone pupae and Varroa mites in various stages of development.

Although most of us are busy checking for swarm cells and adding supers, now is the time to start thinking very seriously about pest control. I was grafting queens last week. While I had the brood frames on the stand I decided to check the capped drone cells that were in the lower corners of the frame. I like to do this to get a feel for the Varroa mite reproduction rates in my colonies. Drone brood tends to facilitate mite reproduction better than worker brood because the drone takes longer to develop, which allows for more time for the mites to reproduce while protected under the cell capping. Of the 20 drone cells I checked, 8 had active mites reproducing in them with an average of 4 nymphs and two adults per drone cell. I then counted the remainder of the capped drone cells on the frame which was 53. So, from the 73 drone cells on the frame, there were possibly 175 mites about to emerge when the drones chewed out of their cells in the next few days.

Varroa mites, adults and nymphs

That was just from the drone cells. These frames were more than 90% in active brood (capped or uncapped), which means that every 21-30 days, these frames will be producing up to 6,500 new bees. Now the worker brood will not produce as many mites as drone brood, but even if it is 50% of what the drone is producing, that means that there is a potential for this frame to produce more than 3,000 mites in the next month based upon the 40% infestation rate I saw in the drones. The funny thing (or actually not so funny at all) is that these are considered hygienic bees. I tell you this because, now is the time to be thinking seriously about how to interrupt mite production in your colonies, which will peak over the next two months.

There are treatments that can be done to control mites during the nectar flow, but they all can cause adverse effects.  Formic acid is a viable option as long as the ambient air temperature remains below 84º F, but those days will be few and far between very soon. Oxalic acid has been released for use during the nectar flow, but it does not penetrate cappings and is likely to have little effect on mites unless treatments are applied in series over several weeks. The third option is Hopguard II which contains acids derived from hops. It, like oxalic acid, is most effective when there is little capped brood, but one advantage of Hopguard II is that it remains active for about a week after the strips are applied, which allows for more residual control. There is no temperature limit as with formic, and it is considered an organic treatment because it is derived from a plant. Of course, chemical treatments, either natural or synthetic, are only partially effective, so it is critical for beekeepers to consider other non-treatment control methods. In other words, I’m talking about cultural control methods that involve how we as beekeepers manage colonies. These non-treatment control methods include:

  1. discarding or freezing drone brood, something that is aided by installing a frame of drone-sized foundation,
  2. installing screened bottom boards, and
  3. creating a brood break either by removing the queen for a week or making splits.

Now is also the time to be on the look-out for small hive beetles (SHB). While SHB are secondary invaders of declining bee colonies, severe pressure from infestations can actually cause an otherwise strong colony to decline and abscond. Soil temperatures are rising this month, spurring the emergence of SHB that pupated in the soil over the winter. These beetles will be attracted to strong colonies, especially ones with strong pollen stores and brood production, although there sometimes seems to be no rhyme or reason why one colony attracts large numbers of beetles while other colonies in the same apiary appear to have very few. The congregation of beetles is a factor of the volatile aromas given-off of the hive as well as aggregation pheromones produced by the beetles (Stuhl and Teal, pre-print 2020). Considering that pheromones may play a role in aggregating beetles, then the more beetles a hive has, the more likely it is to attract more. While strong colonies usually corral beetles and remove their larvae, there is a chance that a peripheral frame that is not well guarded could harbor developing larvae. The larvae exude a slime as they move and feed. If they are allowed to slime the comb, then the bees will avoid it, which then allows the beetles to further expand their ranks and spread. The trick to beetle control is to prevent larvae from fouling the comb. This can be done by tcontrolling adults with traps or catch pads, but more importantly preventing beetle larvae from sliming comb is about minimizing un-patrolled comb and about placing the hive in a dry sunny location that is less hospitable to the beetles. All too often I see bee hives placed in the shade on the assumption that cooler conditions will help the bees. Quite the contrary, placing hives in shady locations may be the single greatest contributing factor to exacerbating SHB infestations.

Last, I have received a number of calls this month from non-beekeepers or neighbors of beekeepers. I have had my ear chewed several times because honey bees are making it difficult for residents with livestock watering systems, swimming pools, bird baths, and even planters on porches because honey bees are visiting these water sources to collect water. To be good neighbors, we as beekeepers must acknowledge that we are keeping livestock and that those managed animals require water just like any other managed animal. This has been a very dry spring, and bees are searching for water. Many of the ditches and tree holes where they normally collect water have gone dry, so they may be concentrated on other available water sources. They typically will use the closest source available which will be in your neighbor’s yard if you do not provide a source in yours. Understand that most counties and cities have nuisance ordinances that allow the municipality to provide enforcement when the activities of one resident affect the quality of life of neighbors. Do due diligence and provide water for your bees on-site. A plant saucer or small plastic swimming pool with rocks or bricks in it is a great way to water your bees. If you have an air conditioning unit, consider putting the dish or pool under the condensation drip line to keep it supplied with water. There also are automatic water dispensers that you can hook to a hose which are triggered by a float. These should be available at most feed and livestock suppliers. Supplying water should not be difficult, but it is important for reducing conflicts with your neighbors.




The Honey Bee Health Coalition

In the past I have referenced the Honey Bee Health Coalition for information about Varroa mite management and treatments, and it remains one of the best repositories for information about integrated management of Varroa. Did you know that the Coalition has so much more to offer than just Varroa control information?

Formed in 2014 in response to unprecedented honey bee colony losses, the Coalition is “a cross-sector effort to promote collaborative solutions to honey bee health challenges. The diverse Coalition brings together beekeepers, growers, researchers, government agencies, agribusinesses, conservation groups, manufacturers and brands, and other key partners dedicated to improve the health of honey bees and other pollinators. The Coalition’s mission is to collaboratively implement solutions that will help to achieve a healthy population of honey bees while also supporting healthy populations of native and managed pollinators in the context of productive agricultural systems and thriving ecosystems.”

While Varroa deservingly receives preeminent attention, the Coalition acknowledges that the health of honey bees and other pollinators is affected by many factors. The Coalition focusses its educational strategy on four fronts: 1) honey bee pests and diseases, 2) forages and nutrition, 3) pesticide exposure, and 4) hive management. Of course, the Coalition serves beekeepers by providing educational resources for factors beekeepers can influence such as Varroa control, colony management, and nutrition, but Coalition members also understand that growers and land managers are stakeholders in protecting pollinator health as well. The strategies used in several crop systems such as corn, soybeans, and canola affect pollinator health, especially the pest management activities in these crop systems, so the Coalition has developed best management practices to help beekeepers and growers collaborate. Because honey bees and other critical pollinators traverse the landscapes that are managed by people of varying interests and backgrounds, any effort to protect their health must engage audiences of every kind.

I hope you will visit the Honey Bee Health Coalition website, especially as you begin preparations for monitoring and controlling Varroa mites this summer. While you are there, take some time to peruse the other resources they provide. There are guides, articles and videos that are very useful for any beekeeper. For the bee clubs that are looking to provide training to members, the Coalition provides a presentation and pre-recorded video on Varroa biology and control. Perhaps this training will help your club begin an open and honest discussion about Varroa mite management.




Long live long leaf

Image of longleaf savannah with open understory and meadowland plants

I’m not sure how many of you have ever visited the Francis Marion National Forest, but, for those that have, you probably will recognize the longleaf pine savannahs that are the property’s claim to fame. Managed intensively with prescribed fire, these open forest systems are known to harbor some of the most diverse plant communities you can find anywhere in the world. More than 900 plant species are associated with this ecosystem, and some studies have found as many as 20 plant species in a single square meter of forest floor.

The longleaf pine system also harbors many of the most threatened and endangered species in South Carolina. Gopher tortoises, red-cockaded woodpeckers, and indigo snakes are a few of the critical animals that call the system home, and about 30 endangered plants are unique to the longleaf pine savannahs.

Why is this system so diverse? Well, it has to do with the frequency of disturbance. While there is some debate about the true origins of the longleaf ecosystem, whether it was an entirely natural system or it was heavily altered by thousands of years of human influence, it is well known that fire and large grazing animals are important factors in controlling the density of trees and allowing the understory to diversify. Naturally, lightning derived fire would burn unimpeded over tens of thousands of acres, and Native Americans would intentionally set fires for purposes of hunting and managing bison herds. These herds would devour and trample vegetation which further disturbed the soil, and, later, wild grazing of cattle by European settlers replaced the effects the bison once had.

Flower of a blue aster, Symphiotrichum sp.

Prior to European settlement, longleaf pine forests covered more than 90 million acres across the southeast, and there were longleaf pine trees large enough to rival the great redwoods out west. Excessive harvesting has since removed the longleaf giants, and the longleaf forest system was reduced to fewer than 2 million acres. Thanks to conservation efforts both in the public sector and among private landowners, this ecosystem is expanding and now covers about 3.5 million acres.

Field of gallberry, Ilex glabra. Photo credit: Chris Evans, University of Illinois,


For beekeepers, this is an important system as well. Of course, the tremendous diversity of plants found in longleaf pine savannahs supports a diverse insect pollinator community, and many of the plant species that support native pollinators also support honey bees. An array of composites (sunflower family) such as Coreopsis and Solidago, legumes such as partridge pea, wild indigo and lespedeza, and numerous showy flowering plants like Liatris, orchids, and Eupatoriums can be found blooming throughout the year in these meadowland habitats. One plant in this system, which is rather inconspicuous but is of major importance to beekeepers is the gallberry or inkberry holly, Ilex glabra. This spindly little holly,

Black berries of the gallberry or inkberry holly, Ilex glabra. Photo credit: Rebekah D. Wallace, University of Georgia,

which is known mostly for its black berries, exists in vast fields where fire is common and soils are moist and sandy. Known as a prolific nectar producer, the gallberry produces large volumes of highly valuable honey towards the end of the spring nectar flow. If you venture to the longleaf pine stands of the coastal plain, you will find gallberries blooming this month.

While most of the managed longleaf savannahs occur on state or national land where access by beekeepers is limited, there are a number of private landowners that have invested heavily in re-establishing this ecosystem. Aided by the Longleaf Alliance, the Nature Conservancy and USDA cost-share programs, forest landowners are replacing loblolly pine forests with longleaf and are returning the disturbances that support plant diversity.This reversion is a benefit to honey bees and to pollinators and insect biodiversity in general.




Terminating old comb after 3 to 4 years has been recommended for a variety of reasons, especially for managing pests and diseases. As it turns out, keeping bees on old comb too long may also reduce the colony’s intrinsic ability to grow and survive. This study introduced bees to various ages of comb and tracked factors such as brood production, worker weight, worker survival, and performance and found that younger comb (less than 3 years old) supported more productive hives.

Mohammad Abd Al-Wahab Abd Al-Fattah, Yasser Yehia Ibrahim & Marwa Ibrahim Haggag (2021) Some biological aspects of honey bee colonies in relation to the age of beeswax combs, Journal of Apicultural Research, 60:3, 405-413, DOI: 10.1080/00218839.2021.1899657


Is the current maximum application rate (1g/brood chamber) for vaporizing hives with oxalic acid sufficient to achieve desired control? This study suggests it may not be statistically different from negative controls. Of course, 1g/brood chamber is the maximum label rate, so it is not advised for beekeepers to treat hives at rates above the legally allowed rate. Perhaps this study will get the EPA to review the label.

Cameron J. Jack, Edzard van Santen & James D. Ellis (2021) Determining the dose of oxalic acid applied via vaporization needed for the control of the honey bee (Apis mellifera) pest Varroa destructor, Journal of Apicultural Research, 60:3, 414-420, DOI: 10.1080/00218839.2021.1877447


A study of Amitraz (Apivar) and its metabolites in honey and beeswax suggest that it does not remain detectible beyond 42 days, which is quite different from other acaricides such as coumaphos and tau-fluvalinate whose residues may remain detectible for months or even years after treatment. Also, even dosing that is 5 or 10 times the current maximum allowable rate did not produce residues that exceed the established maximum residue limits. Again, it is not recommended for beekeepers to exceed the maximum label application rates.

Veeranan Chaimanee, Josephine Johnson & Jeffery S. Pettis (2021) Determination of amitraz and its metabolites residue in honey and beeswax after Apivar® treatment in honey bee (Apis mellifera) colonies, Journal of Apicultural Research, DOI: 10.1080/00218839.2021.1918943




Basics of Entomology – Master Gardener/Master Naturalist training – course is full. Were are developing an online course that should be available later this summer.


South Carolina Beekeepers Association Summer Meeting  – 22-24 July. 2021


Eastern Apiculture Society Annual Conference 11-13 Aug. 2021


Honey bees on a Clemson hive




Clemson University Cooperative Extension Service offers its programs to people of all ages, regardless of race, color, gender, religion, national origin, disability, political beliefs, sexual orientation, gender identity, marital or family status and is an equal opportunity employer.

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