Lesson 64: Small Hive Beetle

A beetle that turns honey to slime: how to spot it, and how strong colonies and traps keep it in check

The small hive beetle (Aethina tumida), or SHB, comes from southern Africa, where it's a minor pest. Since it arrived in the United States in the late 1990s, it has become a serious pest in many areas, especially in warm regions like the Southeast. Almost every beekeeper in beetle country sees them. The goal isn't zero beetles; it's keeping them from taking over.

Know the beetle

Adults: - About ¼ inch long, roughly a third the size of a bee. - Oval, flattened, dark brown to black (reddish when newly emerged), covered with fine hairs; heavily armored, so they're hard to crush. - Run fast across the comb and hide from light and from the bees in corners, cracks and under the lid. - Adults can fly several miles between apiaries.

Larvae: - Small, whitish-cream grubs, up to about ½ inch long, with rows of small spines on the back and three pairs of legs near the head only. - Easy to confuse with wax moth larvae (lesson 65). Beetle larvae are smaller, tougher, and don't have the fleshy extra legs along the body that wax moth larvae do, and don't spin webbing.

How it looks: Adult small hive beetles: small, dark, oval, and quick to run from the light.

Beetle larvae: cream-colored, spiny grubs with legs only at the front.

The life stages: egg, larva, pupa, adult.

The life cycle

1. Adults fly into a hive, hide from the bees, and lay eggs in cracks and in comb.
2. Larvae hatch and feed on honey, pollen and bee brood, tunneling through the comb.
3. When full-grown, larvae crawl out of the hive (often at night, drawn toward light) and burrow into the soil to pupate.
4. New adults emerge from the soil and fly to hives. Several generations can happen in a warm year.

The damage

• Larvae tunnel through combs, kill brood, and ruin new comb especially.
• Beetles defecate in honey, which ferments. It turns slimy and frothy, runs out of the cells, and smells like rotting oranges. Slimed honey can't be sold, and bees won't eat it or clean it up.
• In bad infestations bees may abandon the hive.
• The worst damage is in weak colonies, in small colonies (nucs, mating nucs, observation hives), and in honey supers waiting to be extracted.

Keeping beetles under control

Strong colonies are the best defense. Bees chase, bite and herd beetles into corners and "jail" them there. Only when a colony is weak or has more space than bees can patrol do beetles get the upper hand.

In the bee yard: - Keep colonies strong, queenright and healthy (lessons 42–43, 54). - Don't give colonies more room than they can guard: don't over-super, and reduce the hive size of small or weak colonies (move them into a nuc box). - Feed pollen patties in small amounts (a third of a patty for small colonies) so the bees finish them before beetles can lay eggs in them. - Keep the yard clean: no burr comb, cappings or debris lying around; clean solid bottom boards. - Choose sunny sites where you can; beekeepers find some locations naturally less prone to beetles (soil conditions matter to pupating larvae). - Be careful when combining, splitting or moving combs; these can spread beetles or give them room away from the bees.

Traps (inside the hive): - Many in-hive traps are sold: oil-filled trays between frames or in the bottom board, under-lid and entrance traps, and cloth or fiber pads that snag beetles' legs. Beetles run into them to hide from the bees and are caught. Some use vegetable oil and a bait like apple cider vinegar. - Traps help but don't solve a problem alone, and results vary. Use them along with strong colonies.

In the soil: - Beneficial nematodes (tiny worms, species Steinernema riobrave or Heterorhabditis indica), sold by organic-garden suppliers, can be watered into the soil in front of hives, where they kill pupating larvae. Research found good control of larvae, likely lowering local beetle numbers. - Chemical soil drenches and in-hive beetle chemicals exist, but must be registered for that use and applied exactly by label (lesson 57). In-hive chemicals are of limited use, and none stops adults flying in from elsewhere.

In the honey house (lesson 72): - Extract honey supers quickly after taking them off, within a day or two if you can. Beetles multiply fast in supers away from the bees. - Don't leave cappings or wet equipment sitting out. - Don't stack infested supers onto strong colonies.

If a hive is slimed

• Remove the slimed frames and boxes right away.
• Wash out as much of the fermented honey as possible with a strong hose; the bees may then finish cleaning it.
• Freeze combs to kill any remaining eggs and larvae before reuse.
• If the colony is still alive, reduce it to the space it can defend.

What to remember

• SHB: small, dark, fast, armored beetles; spiny cream larvae with legs only at the front.
• Larvae ruin comb and ferment honey into slime that smells like rotten oranges.
• Strong colonies + no extra space are the main defense; traps and nematodes help.
• Extract honey promptly; don't leave supers sitting.
• Mix-up alert: beetle larvae don't spin webs; wax moth larvae do.

Quick check

1. Where do small hive beetle larvae go to pupate?
2. How can you tell a beetle larva from a wax moth larva?
3. Why shouldn't you leave full honey supers sitting for a week before extracting?

Adapted from: UGA Bee Program, Honey Bee Disorders: Small Hive Beetle; Delaplane, Honey Bees and Beekeeping (UGA Bulletin 1045, rev. 2017); Penn State Extension, A Quick Reference Guide to Honey Bee Parasites, Pests, Predators, and Diseases; University of Arkansas, Complete Beekeeping Short Course, Part 12 (Zawislak); UF/IFAS Extension, Welcome to the Apiary! (4H446, 2024) and Using Nucs in Beekeeping Operations (IN869); Mississippi State University Extension, Beginning Beekeeping in Mississippi (P3594).

Photos: SHB adults and larvae, James D. Ellis, University of Florida, CC BY 3.0 US · Life stages, Huang et al., CC BY 4.0 (all via Wikimedia Commons).

Adapted from university Extension sources. Experienced Georgia beekeepers are reviewing these lessons. See something that doesn't match your experience? Tell us.