CAPPings July 2020

July 9, 2020

July is upon us and little has changed in our progress to get back to normal operations. COVID cases have increased in most counties across the state, halting progress towards reopening extension offices. We remain under restrictions preventing in person programs, and the current situation appears as if it will persist for the foreseeable future.  To that end, the Clemson Apiculture and Pollinator Program is looking to offer more digital learning opportunities this fall. Please stay tuned for those developments, and you can stay up to date by following the Clemson Apiculture Facebook page. Priority number one right now is the revision of our current fact sheets and publications, an arduous task that requires a lot of editing and peer review.  Also, we will be concluding the needs assessment survey by the end of the summer.  If you or your fellow beekeepers have not participated in the survey, you are missing an important opportunity to direct our program development and ensure that your training needs are met.  Please go to the Google Form to complete the survey.  You can also reach it on the right-hand column of our website https://www.clemson.edu/extension/pollinators/index.html.

While National Pollinator Week (June 22-28) did not go as planned because many of the field days we were planning had to be cancelled, we did have some great engagement on the Facebook pages, and our segment on SCETV’s “Making It Grow” received a lot of great positive feedback.  We will continue using those platforms while we are social distancing.  Be on the lookout for another “Making It Grow” segment called “Hollies for Honeybees,” featuring yours truly talking about some of my favorite plants from the genus Ilex.

Many of the local bee associations have resumed meetings and are offering field trainings. For those clubs that are finding it difficult to meet, then perhaps you would like to try a web meeting. I would be happy to help your association, if you need assistance with hosting web meetings. bpowel2@clemson.edu

Kindest regards,
Ben Powell
Clemson Apiculture and Pollinator Specialist

 

For most of the state, July is a stressful month for honeybees. Most areas will enter a dearth of nectar. High heat and humidity can make cooling the hive a significant metabolic cost, and pests are ramping up rapidly.

For the honey producers in the audience, removal of honey stores in June often leaves the bees with limited food resources in July, and beekeepers may choose to feed the bees 50:50 sugar water which provides two services: 1) food for the colony and 2) moisture to aid in cooling the hive. Most beekeepers will notice that building of new comb slows significantly, but maintaining a sugar water source may stimulate the bees to continue drawing new comb. If you are not feeding, you still need to make sure that the bees have a water source nearby. Remember, bees need to maintain the brood chamber temperature at 35° C (95° F) for optimal brood development.  When external temperatures approach 95° F, bees will vigorously seek water to carry back to the hive to cool it.  If your apiary is in a neighborhood or in town, it is critical to provide water in the bee yard this time of year to reduce the tendency of bees to visit neighbors’ pools and birdbaths.  I was tagged in a post this week asking about a “bee swarm” around an air conditioning unit.  The bees were not swarming. Instead, they were gathering water from the condensation drain, and the amount of activity had the homeowner scared to go outside, even though the bees were harmlessly collecting water.  It is also critical to make sure hives have proper ventilation.  Our high humidity forces the bees to move a lot of air through the hives to cool them. Winds from summer thunderstorms can shift covers that are not weighed-down, blocking top vents, so check your hives after storms to make sure the covers are positioned correctly.

Pests are ramping up their attacks on bee hives as we speak. It is time to conduct varroa mite checks and treat if you are so inclined. I have received an increasing number of calls about wax moths.  It might be related to higher rainfall than normal, or the abrupt end to the nectar flow that many areas have experienced.  Maybe it’s just a cyclical or natural phenomenon, but I, too, have experienced increased wax moth activity in the demonstration hives as compared to years past. I figure it is worth a discussion here.

The term “wax moth” actually applies to two distantly related moths, the lesser wax moth (Achroia grisella) and the greater wax moth (Galleria mellonella).  Both species are fairly nondescript brown moths in the family Pyralidae, the main difference between the two being their relative sizes.  Full grown caterpillars of the lesser wax moth reach about 20 millimeters long while the greater wax moth caterpillar reaches 30 mm.  Both species are active in South Carolina from March through October, but South Carolina can experience warm spells in the winter that allow for some limited moth activity.  The adult moths are primarily nocturnal and enter honeybee hives at night while the bees are relatively inactive. It is a safe estimate that every hive in the state will be visited by wax moths every year and probably has eggs or developing larvae in it.

While beekeepers often think of wax moths as pests, they really are better described as commensal organisms in bee hives.  A

commensal organism is one that derives food or resources from another organism without helping it or hurting it.  (Wait! Did he just say wax moths don’t hurt honeybees?!!!)  Yes, wax moths are symbiotic organisms with honeybees and serve as decomposers of abandoned honeycomb.  They actually provide an indirect service to honeybees by removing toxin and disease-laden honeycomb that bees have abandoned.  In fact the arrival of wax moths to New Zealand many years ago resulted in the reduction of American foulbrood prevalence in the country because the wax moths recycled the old disease-ridden comb after colonies died. While wax moths will lay eggs anywhere they can in a honeybee hive, the worker bees will remove any eggs or developing caterpillars from honeycomb that is being used. Wax moths take on average 5 to 7 weeks to develop from egg to pupa, so the only way wax moths can proliferate in a hive is for portions of the honeycomb to go unused by the bees for more than a month at a time.  The solution to minimizing wax moth damage is to ensure that none of the comb goes unused for extended periods of time.

July is a critical month for wax moth management in SC.  As we enter the nectar dearth, bees will consume some of their stores.  This may open up some of the comb to wax moth attack.  Also, queens sometimes reduce their laying rate and brood production in response to limited pollen availability, which further opens-up comb to wax moths. Worker mortality is at its highest in mid summer because of predators, environmental stresses and natural physiology.  Plus, other pests, most importantly Varroa mites, begin to peak in July and August which contributes to a declining workforce in the hive.  These factors may cause portions of the comb to be abandoned for lengthy periods and provide an opportunity for wax moth caterpillars to develop.

Wax moths do not kill honeybee colonies.  They take advantage of the unpatrolled honeycomb in declining colonies. The solution to preventing wax moth damage is to make sure that the workforce can cover all of the comb in the hive.  This can be done through a variety of strategies.

• Replace declining queens. Queen longevity has decreased over recent years, and most beekeepers find they need to replace queens every 1 to 2 years to maintain vibrant colonies.  Vigorously laying queens ensures an expanding workforce which can manage the moths.
• Remove unused supers/frames from declining colonies. You may find that a colony has gone queenless or has swarmed.  Perhaps the colony is declining from Parasitic Mite Syndrome or a brood disease.  If the workforce is declining and there are frames that are not being used for brood or storage, then you need to consider reducing the cavity size to allow the remaining bees to cover the essential comb until you remedy the problem that is causing the decline.  You can constrict a two-box hive to a single deep if necessary.  You can also use a following board to reduce the cavity size in a single brood box. The tendency to swarm usually subsides by this time of year, so increasing congestion in the hive is not as big of a concern as it is in the spring. There is still a chance they will swarm if it is made too congested. Just remember to allow for room to grow once the colony begins to rebound from the decline.
• Manage pests that cause decline. Bees suffering from parasitic mite syndrome do not perform their nursing and hygiene tasks as well as healthy bees.  Varroa mites and their associated diseases account for the majority of the summer declines beekeepers experience.  In fact, last year summer losses increased to some of the highest rates ever while winter losses decreased according to the Bee Informed Partnership annual survey of colony losses.  Varroa mites continue to be a big problem, but small hive beetles also are a concern this time of year.  In-hive traps can help reduce small hive beetle prevalence. While small hive beetles are secondary pests that infest declining colonies, they can foul a declining hive and force the bees to abscond, leaving the moths to ravage the unprotected comb.
• Feed the bees during the dearth. Comb that is being filled with nectar will have bees patrolling it to transfer and dry the nectar.
• Replace aging comb every three years. The primary job of wax moths is to consume old honeycomb, so they are attracted to aged, dark brood comb more so than to new honeycomb. Removing old comb reduces the attractiveness of the hive to wax moths.

The tell-tale sign of wax moth activity is a trail of silk over the honey comb cells. Usually the young caterpillars go unseen because they burrow through the cell walls near the bottoms of the cells.  They construct silk nets over the tops of the cells to avoid patrolling bees, and this silk gives them away. If you see a silken trail, then it is safe to assume that there are other eggs and larvae waiting to develop on that frame. If you find that you have wax moths on unused frames, the simplest way of dealing with them is to remove the frames and freeze them for 24 hours to kill the moth eggs and caterpillars.  The frames can be stored under covered sheds with open sides to allow airflow, which will prevent re-infestation of the comb. The frames can be replaced into the hive once the colony rebounds from decline.

 

Have you met Nancy Lee Adamson? Well, you should, especially if you are interested in pollinator conservation in the southeast.

Nancy is a pollinator conservation specialist for the USDA’s Natural Resource Conservation Service.  She works at the Eastern National Technical Support Center in Greensboro, NC, where she serves the entire eastern US on the technology transfer and assistance team.  She focusses mostly on promoting pollinator habitat conservation through Farm Bill programs. Through the Farm Bill, the federal government encourages pollinator conservation on private lands through a series of incentives programs designed to offset the costs of installing and maintaining pollinator habitat.  The programs are for land that is cultivated for production of a forest or agronomic crop to maintain conservation practices on working farms and forests.  There are a variety of programs, and Nancy can help farm owners and managers determine which programs are suitable for their purposes.  If you own or keep bees on a working farm, you should look into the various conservation programs that can improve pollinator habitat and honeybee forages on the farm, and your local NRCS office can clarify your options.

Nancy also is the southeastern region representative for the Xerces Society for Invertebrate Conservation .  The Xerces Society is the world’s premier invertebrate conservation organization, and they focus heavily on pollinators. “The Xerces Society for Invertebrate Conservation is an international nonprofit organization that protects the natural world through the conservation of invertebrates and their habitats. As a science-based organization, we both conduct our own research and rely upon the most up-to-date information to guide our conservation work. Our key program areas are: pollinator conservation, endangered species conservation, and reducing pesticide use and impacts.”  Xerces is mostly focused on education and provides a wealth of resources helpful to beekeepers and conservationists.  They have region specific habitat planting guides, pollinator identification tools, facts sheets on reducing pesticide exposures, and an array of other resources that you and your local beekeeper association may find useful.  For clubs that engage schools and youth groups, the Xerces Society has developed activities and resources designed for youth audiences. They provide information for conserving pollinators on working farms, in home landscapes, along roadsides and rights-of-way, across urban landscapes and throughout natural areas, and they have developed certification programs for pollinator conscious products (Bee Better Certified) and cities/campuses (Bee City USA/Bee Campus USA). Xerces is the primary sponsor of several citizen science projects such as annual monarch counts and pollinator surveys. Also, they offer webinars and other training programs.

Nancy has participated in Clemson Extension programs such as the SC Master gardener conference, and is excited to support South Carolina’s beekeepers and our mission of public education.  Perhaps when we can safely resume our annual beekeepers meetings we will invite Nancy to teach us more about the Xerces Society and the federal conservation programs that support pollinators

 

Well, it’s not a native, but it is worth discussing.  I saw for the first time a giant resin bee (Megachile sculptularis) in my yard this spring.  Most sightings of this exotic bee come from the upstate, but I can confirm that they are present all the way to Horry county at the coast.

The giant resin bee comes from southeast Asia (sound familiar?). It was first sighted in North Carolina in 1994.  It has since spread across most of the eastern states and extended its range as far west as Kansas.  It is considered to be an adventive species rather than an invasive species.  Adventive means that it has successfully established populations in North America but that it does not appear to cause significant problems for native species, although there is some evidence that there is direct competition between giant resin bees and our native carpenter bees.

Giant resin bees are solitary bees that nest in wood galleries. They behave much like our native mason and leaf-cutter bees which are distant relatives in the family Megachilidae. Giant resin bees are not able to excavate their own galleries, so they must use existing cavities. They often choose to use the galleries constructed by carpenter bees.  There is some evidence that giant resin bees will force carpenter bees out of their galleries, but this behavior does not appear to affect carpenter bee populations negatively.

Giant resin bees pollinate more than 40 plant species in the US, but they appear to show a preference for plants that hail from their home range in Asia.  This means that they preferentially pollinate exotic ornamental plants in home landscapes as well as some invasive plant species such as privet (Ligustrum spp.) and golden rain trees (Koelreuteria paniculata).

The giant resin bee is distinct and easy to recognize by its relatively large head and its sculptured, elongated abdomen.  They are roughly the same size and color as carpenter bees, but the elongated abdomen has very few setae (hairs) on it and is matte rather than shiny like most carpenter bees.

Giant resin bees pose little threat of stinging.  As with most solitary bees, they are not defensive of their nests, and are only inclined to sting if they are trapped.  Some people have reported “swarms” of giant resin bees, but this appears to be congregations using old, well established carpenter bee nests.  These bees are not social and do not display swarming behavior.

Management of giant resin bees is basically the same as for carpenter bees.  Because they do not actually excavate tunnels in wood, they do not usually warrant control.

 

 

Conversations at bee clubs often mention “hive strength” and its effect on controlling pests, generating honey, and supporting pollination services, but what constitutes a “strong” hive and how do you quantify it?  A German researcher proposed a simple method that can be applied to large numbers of hives.  The “Leibefeld Method” has now been translated into English and made available online.
Dainat, B., Dietemann, V., Imdorf, A. et al. A scientific note on the ‘Liebefeld Method’ to estimate honey bee colony strength: its history, use, and translation. Apidologie 51, 422–427 (2020). https://doi.org/10.1007/s13592-019-00728-2

 

This study investigated a variety of potential baits that could be used to deliver small doses of boric acid to kill small hive beetles in bee hives.  Several mixtures worked well, but all required some form of trap to prevent bees from also accessing the bait.
Stuhl, C.J. The development of an attract-and-kill bait for controlling the small hive beetle (Coleoptera: Nitidulidae). Apidologie 51, 428–435 (2020). https://doi.org/10.1007/s13592-019-00729-1

 

Most of us have heard about honey adulteration and the difficulty in identifying it and preventing it to maintain the integrity of honey crops, but are you aware that bees wax also can be adulterated.  This research project investigated a method for identifying adulterated beeswax.
Alexandra Špaldoňová, Martina Havelcová, Ladislav Lapčák, Vladimír Machovič & Dalibor Titěra (2020)Analysis of beeswax adulteration with paraffin using GC/MS, FTIR-ATR and Raman spectroscopy, Journal of Apicultural Research, DOI: 10.1080/00218839.2020.1774152

 

Honey has long been used as a treatment for wounds and sores because it has antimicrobial properties. While its use has waned in the era of pharmaceutical antibiotics, there is renewed interest in honey as a wound treatment as antibiotic-resistant bacteria become more common.  The use of honey in this manner is not without risks, so quality control standards must be established for medical-grade honeys.
Renée Hermanns, Cristina Mateescu, Andreas Thrasyvoulou, Chrysoula Tananaki, Frank A.D.T.G. Wagener & Niels A.J. Cremers (2020) Defining the standards for medical grade honey, Journal of Apicultural Research, 59:2, 125-135, DOI: 10.1080/00218839.2019.1693713

 

 

 

Most of the events scheduled for July and August have been cancelled or postponed due to COVID-19.

If your local association needs assistance holding a virtual meeting while many locations are closed to public gatherings, please contact me.

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