Beetles in a Beehive

How Bees and Beekeepers Control Small Hive Beetles

Small hive beetles (“SHB” ) are pests of honey bee hives. Native to sub-Saharan Africa, they thrive in humid conditions close to colonies. Female beetles lay eggs in the nooks and crannies of hives, hatching into larvae that burrow through the wax frames, consuming bee brood, and hive products. The feeding larvae excretes Kodamaea ohmeri, a yeast that causes the fermentation of the sugars in honey. In severely infested hives, the colony is likely to be destroyed or absconded as a result of being overrun by the beetle larvae and their droppings (“slimeout”).

The most straightforward method of controlling small hive beetles is to keep a strong, healthy colony, as colony strength is what keeps beetles in check. For those hobbyist beekeepers with a few hives, this is an easy task – simply monitor hive activities for a few weeks (a full worker brood cycle of ~21 days) and decide if they require supplemental feeding or a newer, more active queen bee. Additionally, placing beehives on solid ground (concrete) or in full sunlight with little vegetation (dry soils) reduces the risks of severe infestation. If these options are not enough, then several alternatives are listed below.

How do Beekeepers Control Small Hive Beetles?

While small hive beetles are a minor pest in their native Africa, they are a serious threat to weak colonies around the world, a fact I continue to be reminded of firsthand. For beekeepers, this article will describe ways of controlling small hive beetle when keeping a strong colony is not possible. Then, it will explore the ways bees manage these pests within the natural beehive and provide an overview of small hive beetle biology.

Mechanical Traps for Eliminating Small Hive Beetles

If keeping strong bee colonies is not possible, then mechanical methods for small hive beetle control are available. One such instrument is the “Silver Bullet” design of beetle traps, containers filled with a substance that kills beetles, such as vegetable oil (drowns them), diatomaceous earth (cuts through the insect’s cuticle) or lime (dries out their moist membranes, leading to death by desiccation). A silver bullet trap is placed between frames, serving as another dark space for the beetles to hide in. Unlike the brood comb however, once they go in, they do not (usually) come out.

Entrance traps are structures designed to fit at the hive entrance and allow bees to pass through, but not the adult small hive beetles. Generally, their mesh structure has openings that are are too small for the bees, with some designs featuring bottom holes that take advantage of the beetle’s inability to hover, thus making them fall outside hive. Entrance traps can reduce the number of beetles entering, however they do not address those already inside the hive, and so multiple control methods are required to manage small hive beetle infestations.

Making Use of the Screened Bottom Board for Controlling Pests

To control the number of beetle larvae, consider a mesh/screen hive bottom board with a solid tray underneath. Like the silver bullet beetle traps, this tray is filled with soapy water, vegetable oil or lime, drowning any adult beetles and larvae that fall from the hive as bees chase them. The mesh is large enough for the beetles to fall through, and too small for bees to pass.

For those wanting an easier-to-dispose option, a cloth trap using cleaning fabric like flannel will have fibers that trap the beetle’s legs, and can be disposed of every few days to kill the ensnared beetles. This method requires regular replacement even if the hive has a low beetle count; the accumulation of propolis, pollen, and other hive debris onto the board decreases the cloth’s effectiveness.

The bottom board method is very effective in stronger hives as the honey bees allocate workers to actively chase beetles. Remember to regularly clean and refill the tray to maintain its effectiveness!

Chemical Treatments for Small Hive Beetles

Chemical traps are available and can be used in any stage of a small hive beetle infestation. One example is the commercial brand Apithor, which uses a proprietary beetle bait laced with the insecticide fipronil, (this insecticide is also lethal bees, and the trap is designed to make it difficult for bees to come contact it). In general, adult small hive beetles are attracted to the scent emitted by the trap, where they ingest the bait and succumb to fipronil poisoning (blockage of the GABA-gated chloride channels leading to death by nerve overstimulation, for those wondering). Apithor is placed on the bottom board or on the top bars between frames. A device lasts for several months, and one trap per hive is sufficient, however multiple traps may be used in severe infestations.

Other examples include the organophosphate insecticide coumaphos (CheckMite+, chemical strips that go inside the hive) and the pyrethroid permethrin (GardStar, a liquid used around the outside of hives for ant and beetle control). Coumaphos strips are commonly used inside beehives for the control of mites such as Varroa destructor, and there are risks associated with contamination of wax and stored honey, as well as the sublethal effects from the pesticide. For readers familiar with the effects of pesticides on honey bees, they’ll know that applying the liquid permethrin around the hive (or inside the hive, if you don’t read the instructions!) will have environmental affects on non-target insects and aquatic organisms.

Chemical Varroa Treatments also Reduce Beetle Populations

Chemical treatments used for Varroa mite control have the second order effect of killing small hive beetles, however these insecticides still impact honey bees. For example, if formic acid is given in too high doses at too high temperatures, the resulting vapor concentrations are intolerable to the bees, leading to either absconding (also common in thymol overuse), brood death, impacted queen health, or complete colony loss (reviewed in Bartlett, 2022). On the other hand, oxalic acid is less threatening to honey bees, but cannot penetrate the wax cappings and subsequently the brood comb where mites and some small hive beetle eggs are found, so the majority of pests within the colony are not exposed to the treatment.

In general, large-scale chemical control options are rarely used; it is difficulty to identify which insecticides are effective against small hive beetles (from the Order Coleoptera) but safe for honey bees (Order: Hymenoptera), who both belong to the Class Insecta (discussed in on the scientific name of bees, and more broadly in an introduction to Hexapoda).

Are there “Organic” Treatments for Hive Beetles?

The basis of organic treatments for small hive beetles are through non-chemical or “natural” methods that aim to manage beetle populations with minimal harm to the bee colony. The entrance, bottom board and inter-frame traps described above are such examples. The remaining methods aim at controlling external factors such as:

• Placing hives on concrete or areas with limited soil cover to reduce the number of suitable environments for pupation of beetle larvae. Yes, this is easier to perform for the hobbyist or urban beekeeper.
  • If the location consistently experiences high beetle infestations, consider placing hives elsewhere, or to a new bee yard.
• Providing proper ventilation, for example, a screened hive base and moving the hives into a sunny spot to reduce the buildup of the humidity that beetles require for survival.
• Adjusting the hive size to the bee population by limiting empty comb. Beetles will lay eggs in the unprotected comb, so removing honey supers to fit the current bee population (less supers in winter, more in spring/summer) reduces the number of suitable spots.
  • For the removed frames, freeze them for at least three days to stop the beetle eggs hatching (to my knowledge, there is no exact duration in the scientific literature, so a few days in the freezer is enough to kill the eggs).
• Preventing beetle larvae from reaching the soil to pupate by applying a layer of diatomaceous earth around the hive perimeter. The crawling larvae will come into contact with the powder, whereby the fossilised diatoms absorb the thin wax layers on insect exoskeletons, increasing permeability and water loss to cause death by dehydration (Agrafioti et al., 2023). Be sure to replenish it often!

Nematodes in Small Hive Beetle Control

Nematodes have been mentioned as a class of organic pesticides harmless to bees. Referred to as “entomopathogenic nematodes” in the scientific literature, these roundworms from the genera Steinernema and Heterorhabditis show promise in controlling soil-dwelling pests like small hive beetle larvae (Sanchez et al., 2021). Juvenile nematodes invade the body cavity of their target and release bacteria that kill it within 24 hours, producing a cadaver that will be used as a food source for 2-3 generations of nematodes and spreading that same bacteria to the juveniles, thus restarting the life cycle (Kiontke & Fitch, 2013).

This is a method of controlling beetles in a local, vegetative area, and will not be effective if colonies are frequently moved, as in those hives used for commercial pollination. Further, if the area already has a large number of adult beetles, then there are less larvae for the nematodes to consume, and if those beetles manage to lay eggs that hatch, you can bet the hive will slimeout before the larvae goes to pupate.

From a beekeeper’s perspective, they have to ensure that their nematodes are in good health when delivered from the supplier, even using a microscope to visualize the status of the population if required. Should the beekeeper want to invest in their own nematode farm, then the capital requirements are beyond the scope of this article, and are instead redirected to the review by Koppenhöfer et al., 2020 for further reading on entomopathogenic nematodes in agriculture.

How Strong Honey Bee Colonies Control Small Hive Beetles

Colonies with large populations control small hive beetles by herding them into the unused nooks and crannies of the hive box (formally called corralling). Any beetle eggs laid are removed by bees, and studies have shown that when small hive beetles are corralled, they do not lay eggs in their makeshift prisons.

Further, when more worker bees are available, more resources are allocated to defensive bee-haviors such as biting, stinging, and wrestling (this last point was observed by your humble author one spring morning). Indirectly, strong colonies maintain optimal hive conditions for raising bee brood, and these are unfavorable for small hive beetle development.

An Optimal Hive Temperature is Detrimental for Beetle Egg Survival

Meikle and Patt (2011) found that beetle eggs hatch at lower rates with increasing hive temperature, and that the egg development lasts longer. Strong colonies can maintain the optimal brood rearing temperature of 35°C, which greatly impacts beetle egg survival. This impacts extends to the beetle larvae, who showed reduced survival at higher temperatures, irrespective of the diet they’ve been fed. At higher temperatures, the survival of adult beetles was also reduced, 20 days at 35°C compared to ~105 days at 32°C degrees and well over 150 days at 25°C degrees.

At higher temperatures, the female small hive beetles laid less eggs (also suggesting some infertility as a consequence of high temperatures), and those eggs hatched sooner (another consequence in that the larvae had less time to develop inside the egg). The authors found a ~25% egg survivorship at 35°C, which suggests that beetles will not do well in the brood box of health colonies and would favour the honey supers for egglaying.

Bonus: African Honey Bees and Small Hive Beetle Control

European bees are more susceptible to beetle damage than their African counterparts, with the latter showing stronger defensive behaviours. The 2003 study by Ellis & colleagues showed the Cape honey bee, Apis mellifera capensis, exhibiting hygienic behaviour in response to the presence of small hive beetle eggs. As both species are native to the region, they have developed a sort of evolutionary arms race against one another:

• Beetles confined to empty honey combs have learnt to pierce the adjacent cell and lay eggs.
• The pierced cell triggers a cleaning response in the infested brood combs, resulting in removal of said eggs.

Additionally, the Cape bee is capable of constructing “prisons” using propolis to control small hive beetles (Neumann et al., 2001). The guard bees hold a constant numbers of beetles inside the cells, increasing the number of propolis prisons when beetle density increases, rather than the numbers of beetles per existing cell.

The authors suggest that this defensive behaviour evolved as a way to manage beetle infestation and limit their proliferation within the honey bee colony. However this imposes a selection pressure in which the beetles most resistant to starvation survive. Some 20-years later, research from from Papach and colleagues (2020) showed that beetle populations within their native African geographies had a higher tolerance to starvation (females survived up to two months without food) than beetles in their invasive North American range.

Small Hive Beetle Infestations in Non-European Honey Bees: Apis dorsata

As part of a routine survey in the mangrove forests in West Bengal, a colony of A. dorsata was spotted with unusual damage: half-sized comb (Garain et al., 2026). The giant honey bee builds exposed comb on thick tree branches, and to see one with a truncated “u-shape” suggested an abnormality. The author found the lower portion of the comb on the ground, right below the nesting site with “dark brown adult beetles”‘ hiding underneath and “creamy white larvae” crawling throughout the structure. The recovered honey was covered with a slimy substance that smelled just like a slimed-out hive.

Now you may be thinking “hang on, adult beetles try to avoid the light, how are they managing on the exposed comb of A. dorsata?”. You are correct, and the authors speculate that it is a behavioural adaptation of A. tumida that drove it to seek these exposed comb¹ (Garain et al., 2026). It does impose a risk to the nests of A. dorsata (who are migratory and tend to jump between combs). Human bee hunters of wild colonies also know to take the honey and leave the brood intact, thus ensuring the colony survives, alas small hive beetles do not know such moderation.

Small Hive Beetle Detection

It’s up to the beekeeper to detect small hive beetles early, and then decide what course of action is required. Routine hive inspections are the most effective way to do so, by looking at:

• The frames, to see adult beetles crawling in and out of empty cells,
• The bottom board, to see if any beetle larvae² or adult beetles have drowned in it,
• The underside of the hive lid for beetles crawling around its surface.

Once detected, determine if any actions are required. For strong colonies, regular monitoring will suffice. For weak colonies, the management options provided above are a good start to helping the colony survive.

Small Hive Beetles as Disease Carriers?

Research has shown that small hive beetles are capable of carrying and transmitting honey bee diseases. For example Cilia et al., (2018) reported that spores of Nosema ceranae were carried inside the digestive organs of adult beetles. These findings however, do not suggest that the adult small hive beetle is a vector or transmitter of N. cerana, as the spores could have been ingested from contaminated products in stored comb, or when fed by worker bees in situations like imprisonment.

Moreover, Huang et al., (2019) catalogued the microorganisms present in both small hive beetle forms and found two pathogenic viruses: Deformed Wing virus and Kakugo virus (the latter a subtype of Deformed Wing Virus, and is thought to cause aggressive bee-haviors). The authors suggest that the beetles acquired these viruses from their diet of hive materials, and found the deformed wing virus capable of replicating inside the adult beetles, which could spread infections.

Small Hive Beetle Biology

If you’ve read this far, may as well learn something about the biology of these insects. Aethina tumida originates from sub-Saharan Africa and has been introduced to the rest of world with populations thriving in regions with similar climates like North America and Australia.

Appearance

Adult beetles appear (very) dark brown or black and 3- 4 millimeters long with a clubbed antenna (No, the illustrations used here are not a very good depiction of the species). Their larvae are a cream to light-brown colour, up to 12 mm long when fully grown. Beetle larvae have a slender, segmented body and six “prolegs” at the head segment. The head itself is small and difficult to distinguish from the rest of the body.

Behavior & Diet, an Overview

This could be an article of its own

Larval Behaviors

In weaker hives, larvae are found in clusters, feeding on honey bee eggs, stored honey and pollen. As they feed, they excrete the yeast Kodamaea ohmeri which consumes the sugars in honey, leading to fermented honey. During mass larval feeding, the colony could collapse as the queen stops laying eggs and the bees abscond, causing the larva to feed freely (Amos et al., 2018). It appears that the odours emitted from the fermenting hive products are a form of positive feedback loop, as Torto & collleagues (2007) found more adult beetles congregating at the bee-less hive in response to the larval feeding.

Adult Behaviors

If you’ve ever spotted an adult beetle, you’ll know that they are skittish, fleeing rapidly from the light in search of a a dark spot for hiding. As mentioned above, beekeepers in Africa using Cape honey bee colonies may see the propolis prisons constructed by bees to control beetles, and this has also been observed in European honey bees (Ellis et al., 2003). When disturbed and with nowhere to run, the adult beetles “play dead”, tucking in their legs as a protective mechanism from both the bees and beekeepers. While this makes it harder for the bees to move them, it is of no problem to crushing might of the beekeeper’s fingers.

Like larvae, they also consume bee brood, hive pollen and honey stores, favouring fermented colony products over those gathered by bees, supporting the relationship between larval feeding and adult beetle numbers. Adult small hive beetle can fly long distances, and are attracted to the scent of bee colonies (including some bumble bee colonies from Bombus impatiens [Hoffmann et al., 2008]), favouring those weaker, stressed hives with scents of fermented hive products (Torto et al., 2007).

Lifecycle

Females mate inside the hive and lay eggs in crevices (for strong colonies) or within the brood area and pollen stores (in weak colonies). These eggs hatch after 1-3 days, whereby the young larvae begins to feed. After around 13 days, the larvae are fully grown and leave the hive in search of soil to pupate.

Beetle larvae burrow into moist, soft soils, forming a small chamber for pupation. This phase lasts up to 3-4 weeks, and is governed by factors like humidity and temperature of the soil (as described above in the work of Meikle and Patt (2011)). The newly-emerged small hive beetle adults are more likely to be female, which are characteristically bigger than males (Papach et al., 2019) and do not reach sexual maturity until seven days post-emergence, at which stage they proceed to locate another hive to feed, mate, and lay eggs, continuing the cycle.

Strong Colonies Control Hive Beetles

It’s as simple as keeping strong colonies. Can’t keep strong colonies? there are a variety of tools available, from an entrance trap to a bottom board oil pool, or homemade apple cider vinegar traps. Chemical treatments are not recommended for small hive beetles, however if they’re being used for controlling Varroa mites, then small hive beetles are not the most important problem in that colony!

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Footnotes

1. Perhaps it could be due to “desperation”, as in there are no suitable cavity colonies nearby or they are fiercely defending (possible for A. mellifera, unlikely for the skittish A. cerana). As a result of chance, the one beetle that landed on open comb found itself still alive and unmolested, where it proceeded to lay eggs and reproduce, with the larvae being none the wiser, digging and eating and defecating. ↩︎
2. Late to address this point: beetle larvae looks very similar to the wax moth larvae. Small hive beetle larvae have six legs underneath the head capsule, whereas wax moths have it all over their bodies. Wax moth larvae grow larger than the beetle’s, and behave differently inside the hive; a topic for a future article. ↩︎