Hive Beetles: Bee Pests
The Small Hive Beetle (SHB), Aethina tumida, is a significant bee pest originally from Africa, where it remains a relatively minor issue for local honey bee species thanks to their evolved defenses. However, its introduction to Florida in 1998, likely via container traffic from South Africa, marked the beginning of its rapid spread across North America and into regions like Hawaii and Australia. The honey bee sub-species found in these areas, as well as Europe, lack effective defenses against SHB, leading to considerable challenges for the beekeeping industry.
By 2014, SHB had made its way to Italy, and despite efforts to eradicate it, the beetle has become established there. Although not yet detected in the UK at the time of this note, the prevailing sentiment is that it's a matter of "when" rather than "if" SHB will arrive. The anticipated impact of SHB on beekeeping in the UK is expected to surpass even that of the varroa mite, suggesting significant adjustments will be necessary in beekeeping practices to manage this pest. Vigilance, along with prompt reporting of any suspected sightings to the bee inspectorate, is crucial in monitoring and controlling the potential spread of SHB to ensure the health and sustainability of bee populations.
The lifecycle of the Small Hive Beetle (SHB) remains an area of ongoing research, with many aspects not fully understood. Upon reaching adulthood, SHBs measure about 6 mm in length, starting off light brown in color and darkening to nearly black as they age. Their size can vary significantly, influenced by environmental conditions and their diet. For identification purposes, there are three distinctive features to look for:
Club-shaped antennae: This unique feature distinguishes them from many other beetles.
Wing cases shorter than the abdomen: The beetle's abdomen protrudes beyond its wing cases, a characteristic not commonly seen in other beetle species.
Sharp ‘points’ at the rear of the thorax: These points, when the beetle contracts, form a smooth edge to the abdomen, making it more challenging for bees to grip and remove the beetle from the hive.
These identifying traits are crucial for beekeepers and researchers in monitoring and managing the presence of SHB within hives, aiming to mitigate its impact on bee colonies.
Upon reaching adulthood, Small Hive Beetles (SHBs) are known to actively seek out bee colonies, primarily during dusk, believed to be drawn by the scents emitted by the bees, especially the alarm pheromone released during hive disturbances. This attraction is notably stronger following the manipulation of colonies by beekeepers, leading to a higher likelihood of invasion during such times.
Female SHBs exhibit a specific behavior in their egg-laying process, choosing crevices within the hive for this purpose. They tend to deposit their eggs in clusters, favoring locations such as loose frame spacers or areas near the hive's end wall, which offer suitable hiding spots. Additionally, they are known to lay eggs directly on food sources within the hive, including pollen and brood, ensuring immediate food access for the emerging larvae. The eggs, measuring 1.4 mm in length, appear pearly white.
An intriguing aspect of SHB behavior within the hive is the interaction between the beetles and the honey bees. Bees often corral the beetles into specific areas, effectively creating 'prisons' for them. Yet, in a surprising turn of behavior, bees are thought to feed the beetles when prompted by the beetles stroking the bees' mandibles, triggering the bees to regurgitate food.
Upon hatching, SHB larvae waste no time and begin to feed on available food sources. They show a preference for bee brood but do not shy away from consuming nectar, pollen, and honey with equal gusto. This voracious feeding can have devastating effects on the hive, emphasizing the need for vigilant monitoring and management practices by beekeepers to protect their colonies from SHB infestations.
As Small Hive Beetle (SHB) larvae feed within the hive, they defecate on the combs, causing the honey stored within to ferment. This fermentation process not only spoils the honey, making it unusable, but also creates a distinctly unpleasant smell reminiscent of rotten oranges, further indicating the presence of an infestation. The extent of the damage SHB can inflict on a bee colony is significant, particularly in severe cases where a colony might host up to 30,000 larvae. Such infestations can lead to the rapid decline of hive health and productivity.
Beyond the immediate impact on the hive's brood and honey stores, SHBs also pose a threat to stored honey supers that are yet to be extracted. They can infiltrate these storage areas, destroying the honey and comb, and complicating the beekeeper's efforts to manage hive resources and maintain colony health. This underscores the importance of rigorous hive inspection practices and the implementation of preventive measures to safeguard colonies against the destructive impact of Small Hive Beetle infestations.
Control of SHB
If efforts to eradicate the Small Hive Beetle (SHB) prove unsuccessful and the pest becomes a permanent concern, beekeepers must adopt a series of control strategies to manage and mitigate its impact. Chemical interventions are among the options available; however, their effectiveness is limited, and they must be applied with caution to avoid environmental harm. As a result, the emphasis shifts toward an integrated pest management approach, incorporating several key practices:
Good Management and Hygiene: Maintaining clean and well-managed hives is foundational. This includes regular inspections and prompt removal of any hive components infested with SHB or showing signs of damage.
Vigorous Colonies: Strong, healthy colonies are better equipped to defend against SHB invasions. This involves ensuring adequate nutrition and addressing any other pest or disease issues promptly.
Tolerant Bee Selection: Where possible, selecting or breeding bee strains that exhibit natural resistance or tolerance to SHB can be beneficial.
Physical Hive Modifications: Avoiding the use of frame lug spacers, which provide convenient crevices for SHB to lay eggs, can reduce the chances of infestation.
Apiary Site Management: The location and condition of the apiary play a significant role in SHB management. Sites should be sunny, with well-drained soil to discourage larvae from pupating in the ground. Rotating apiary sites can also help prevent the establishment of pupation sites.
Facility Care: Vigilance is crucial not only in the apiary but also in areas where honey is extracted, stored, and bottled. Ensuring these areas are clean and free from SHB can prevent the pest from spreading or contaminating honey products.
By integrating these practices, beekeepers can develop a comprehensive strategy to control SHB, even in scenarios where the pest has become established. This multifaceted approach is vital for protecting hives and maintaining the health and productivity of bee colonies in the face of SHB challenges.
To combat the Small Hive Beetle (SHB) effectively during its active season, beekeepers must become adept at removing beetles at all stages of their lifecycle from within the colony. One effective strategy involves the use of traps specifically designed to capture SHB, allowing for their removal without significant disruption to the bees. Once trapped, the beetles can be exterminated by submerging them in a bucket filled with soapy water. This method is efficient in suffocating the beetles, but it’s crucial to securely cover the bucket to prevent accidental harm to the bees, which might also be attracted to the container.
In cases where colonies are heavily infested and the structural integrity of the combs is compromised due to the activities of SHB larvae, a more drastic measure may be warranted. Affected combs should be removed entirely from the hive and submerged in soapy water. This action not only eliminates the larvae and potential eggs present on the combs but also helps prevent the further spread of the infestation within the hive.
These methods, while simple, require careful execution to minimize harm to the bee colony while effectively managing the SHB population. Such practices, combined with the comprehensive management strategies previously outlined, form an integrated approach to controlling SHB in beekeeping operations.
Trapping
Trapping is a key strategy in managing Small Hive Beetle (SHB) populations within bee colonies. By providing specific traps that mimic the crevices SHB seeks for hiding and egg-laying, beekeepers can effectively lure and remove these pests from the hive. There are primarily two types of traps employed for this purpose:
Correx Card Strips: These strips are made from a plastic card material with slots that are sized to allow beetles entry while excluding bees. Beekeepers place these strips on the hive floor and inspect them during each hive check. The strips can be submerged in soapy water to kill any beetles or larvae captured. Additionally, a visual check is possible by tapping the strip on a hard surface to dislodge and identify trapped beetles. This method is particularly useful for monitoring SHB presence and is readily available from beekeeping supply vendors.
Fly Swat Traps: Resembling the common household fly swatter, this device is modified for SHB trapping by attaching two squares of plywood, creating a narrow gap between them. This gap is inviting for beetles seeking a hiding spot or a place to lay eggs. The swat is placed on the hive floor, allowing beetles to enter the crevice. Upon inspection, the beekeeper removes the trap, containing the beetles, larvae, and eggs, and proceeds to suffocate them in soapy water.
It's important to note that SHB tends to target weaker colonies first. Therefore, while monitoring for SHB, beekeepers might not need to check every single colony but should focus on those appearing more vulnerable. If an infestation is suspected, documenting with photographs or collecting samples to notifying a local bee inspector is crucial for confirmation and to receive further guidance on managing the infestation. This proactive approach to trapping and monitoring helps protect colonies from the significant threats posed by SHB.
Traps designed to suffocate Small Hive Beetles (SHB) and their larvae offer another effective line of defense for beekeepers. These traps typically take the form of trays or troughs equipped with slotted covers. The slots are precisely sized: large enough to allow beetles and larvae to enter but small enough to keep honey bees out, safeguarding them from becoming unintended victims of the trap.
To function, these traps are partially filled with vegetable oil. The oil acts as both an attractant and an agent of suffocation for the beetles and larvae that enter. Once inside, the pests are unable to escape and eventually succumb within the oil. This method of control is particularly appealing due to its simplicity and effectiveness. The vegetable oil not only ensures the pests are efficiently trapped and killed but also facilitates easy cleaning and maintenance of the traps. As long as the oil remains in the trap and doesn't dry out, it continues to be an effective tool in managing SHB populations within the hive.
For beekeepers battling SHB infestations, incorporating oil traps within the hive can significantly reduce the number of pests, thereby protecting the colony and its resources from the destructive behaviors of beetles and larvae. This method, alongside diligent hive inspections and management practices, forms a comprehensive approach to safeguarding bee colonies against the threats posed by SHB.
Checkmite+ is a chemical treatment originally formulated for controlling varroa mites, which has found an alternative use against Small Hive Beetles (SHB) despite not being officially licensed for this purpose in the UK. To utilize Checkmite+ for SHB control, beekeepers adapt the treatment by cutting a varroa strip in half and attaching it to a piece of corrugated cardboard or plastic. This assembly is then placed on the hive floor, corrugation facing down, creating an environment that lures beetles into contact with the chemical.
This adapted method relies on the beetles' natural behavior to seek hiding places, thereby ensuring they come into direct contact with the Checkmite+ treatment. The setup is left within the hive for a duration of six weeks to maximize its effectiveness against the beetle population.
While Checkmite+ strips have shown to be effective in this modified application for SHB control, their traditional use, hanging between brood frames for varroa mite management, does not yield significant results against SHB. This highlights the importance of application method in the effectiveness of chemical treatments.
Additionally, some beekeepers have experimented with using cat and dog flea treatments as a method to combat SHB. These treatments are placed in specially designed applicators on the hive floor, which are effective against the beetles while being designed to exclude bees, minimising the risk of toxicity to the colony. However, it's crucial to note that these treatments are highly toxic to bees and should be used with extreme caution, ensuring bees cannot come into contact with the substance.
