by LUIS RODRIGUEZ, UF/IFAS Polk Extension
Beekeepers play an essential role in modern agriculture as their managed honey bee colonies are responsible for pollinating approximately 85% of the crops consumed today. However, the health and productivity of these colonies are increasingly threatened by a variety of pests. If not properly managed, these pests can spread diseases, deplete hive resources, and compromise hive health and structure. Therefore, beekeepers must be equipped to accurately identify these threats and implement effective control measures to protect their colonies. This article examines three common pests that every beekeeper should be aware of to help prevent issues within their hives
Varroa Mites (Varroa destructor)
Varroa destructor (Anderson and Trueman) is widely regarded as the most detrimental pest affecting Western honeybee populations both in the United States and worldwide. This parasitic mite is prevalent across the U.S. and can be identified by its reddish-brown color and small, pinhead-sized body, which is visible to the naked eye. Despite being visible, Varroa mites often hide between the abdominal segments of bees, making detection by beekeepers challenging.
Varroa mites feed on the fat bodies of bees and are transmitted through direct contact from one bee to another. Their entire life cycle occurs within the hive. Nurse bees, when feeding larvae, can transmit mites to the brood. Before brood cells are capped, mites enter. Once capped, they lay eggs and reproduce within the cells. One of the most serious consequences of a Varroa infestation is the transmission of Deformed Wing Virus (DWV), which often manifests in newly emerged worker bees.
Monitoring and Control of Varroa Mites
Effective monitoring and control are essential for managing Varroa mite populations. Common detection methods include:
- Sticky boards with screened bottom boards: These allow for the collection and counting of mites that naturally fall off bees, providing a baseline for infestation levels.
- Drone brood inspection: Removing and examining drone brood, which mites preferentially infest, is a good alternative method of lowering mite populations.
- Alcohol wash: This is one of the most accurate methods for monitoring mite levels and involves agitating a sample of bees in alcohol to wash the mites out of the abdomen segments of bees to be able to count them. Unfortunately, the sample bees are killed in the process.
- Sugar shakes: Like the alcohol wash, this method involves the shaking of bees in a container with powdered sugar to force the mites out of the abdomen segments of bees. It does not kill the sample bees, but it is not as accurate as the alcohol wash.
Several miticides, such as amitraz, are available for use in managing Varroa populations within colonies. When applying chemical treatments, it is critical to follow all label directions and safety guidelines to ensure effective and responsible use.
Small Hive Beetles
The Small Hive Beetle (Aethina tumida) is an invasive pest originally prevalent in the southern United States, but it has since spread to numerous other regions, particularly in areas where bees are imported for pollination. This small, black beetle is often observed moving quickly within the hive when exposed to light. Its larvae are sometimes mistaken for those of the wax moth (although they are smaller); however, unlike wax moth larvae, Small Hive Beetle larvae do not spin cocoons and leave behind a distinctive slime trail within the hive.
While strong colonies with robust bee populations are generally able to manage small hive beetles on their own, infestations can cause considerable damage in weaker hives. These beetles consume essential hive resources, compromise comb structures, and may ultimately result in the loss of stored honey. Colonies that are compromised or queenless are particularly susceptible, as small hive beetles tend to be most destructive under these conditions.
Common Management Strategies:
- Better Beetle Blaster Trap: Suspended between frames, this trap uses apple cider vinegar as an attractant and oil to eliminate the beetles once they enter.
- Tray Trap (West Beetle Trap): Positioned on the hive’s bottom board and filled with oil, this trap captures beetles that fall through the hive.
- Unscented Swiffer Sheets or Shop Towels: Cut into smaller pieces and placed on top of the frames, these materials trap beetles as they become entangled in the fibers.
- Maintaining Hive Health: Small Hive Beetles are opportunistic pests. Healthy, populous colonies are better equipped to defend themselves, reducing the likelihood of infestation. Conversely, weak or underpopulated hives are more susceptible.
Regular monitoring and prompt intervention are critical to minimizing the impact of Small Hive Beetles on honey bee colonies.
Wax Moths
In the United States, two primary species of wax moths are found: Galleria mellonella (Greater Wax Moth) and Achroia grisella (Lesser Wax Moth). These opportunistic, secondary pests primarily target weak or stressed bee colonies. Once established, their larvae tunnel through wax combs, spin webs, deposit frass (feces), and consume wax, pollen, and honey. They also chew holes in brood cappings and may even damage wooden components such as hive boxes and frames. Wax moth infestations can lead to colony absconding and are particularly problematic in stored comb, especially dark comb that has previously housed brood.
Control of wax moths
As previously noted, wax moths are opportunistic pests that primarily target weakened hives. Therefore, the most effective method of controlling wax moth infestations is to maintain strong, healthy colonies. Proper swarm management is crucial, as swarming can reduce the number of bees defending a hive by half or more, increasing vulnerability to infestation.
If a frame is found to be infested with wax moths, it should be frozen for a minimum of 24 to 48 hours to eliminate any larvae, pupae, or adult moths. Additionally, in storage areas where frames are kept without bees, regular fumigation is recommended as an effective preventative measure against wax moth damage.
Vigilance and Action
Honey bee colonies face significant threats from pests such as Varroa mites, Small Hive Beetles, and Wax Moths, each of which can severely impact hive health and productivity if not properly managed. Effective monitoring, timely intervention, and maintaining strong, healthy colonies are critical strategies for beekeepers to protect their hives from these stressors. By understanding the biology and behavior of these pests, beekeepers can implement targeted control measures that reduce infestation risks and support the vital role honey bees play in agriculture and the environment.
For more information about Varroa Mites, Small Hive Beetles, or Wax Moths, please read the following “Ask IFAS” Publications:
Varroa, Varroa destructor Anderson and Trueman (Arachnida: Acari: Varroidae)
Small Hive Beetle, Aethina tumida Murray (Insecta: Coleoptera: Nitidulidae)
Luis Rodriguez is the Polk County Small Farms and Pesticide Education Extension Agent. You can reach him at lrodriguezrosado@ufl.edu or 863-519-1049.