Winning the Battle over Small Hive Beetles
By: Nanette Davis
Beekeepers anywhere in Texas or neighboring states are likely to have opened a hive at some point and caught sight of a small dark beetle scurrying about like a minuscule rat across the inner cover.
For the lucky beekeeper, a glimpse is all that has been seen of the Small Hive Beetle (SHB). For others however, a hive overrun by a hoard of beetles that resulted in the bees absconding and a disgusting slime out have been a reality.
Fortunately, most beekeepers have been somewhere between these two scenarios and continue to search for methods to limit the potential harm from these pests. Gaining an understanding of SHB and some techniques to reduce their numbers can help beekeepers safeguard their colonies and decrease anxiety when dealing with these small insects.
SHB are an invasive species in North America that thrive in warm climates. However, they are also adaptable to colder regions because they can overwinter inside a hive and live up to six months.
The beetles locate hives by smell and prefer locations in shade. An adult female can lay more than a thousand eggs in her lifetime. Clusters of eggs are laid in crevices or directly in comb and hatch within 2-4 days.
Remember the hatch period of 2-4 days? A few beetles can turn into hundreds of larvae within one week; and unlike the tidy bees that go outside the hive to eliminate waste, the beetles and larvae eliminate inside the hive.
It is this contamination that contains a specific yeast that can quickly result in the notorious slime out where fermented honey drools out of the hive - resulting in the bees absconding in search of a healthier home, and the beekeeper is left with a nasty mess to clean up.
So, what can be done to address these unwanted guests? Being proactive is the best policy to avoid SHB problems.
- Maintain strong colonies
- Keep hives on dry ground in sunnier locations
- Be fast – the minute you open a hive be ready to kill as many SHB as you can with your hive tool!
- Use in-hive traps and screen bottom boards
- Leave propolis in place for the bees to keep cracks sealed
- Keep bees crowded – bees can’t defend “too much space”
Common Traps and How to Use Them
The least expensive - Beetle Blaster (for example) is inserted between frames 3 or 4 and can be doubled up on each side of the brood box as well as in top brood box if needed. As beetles seek shelter in the traps from the bees chasing them, they become trapped and die in the oil or DE. Fill ½ way with vegetable oil or DE (diatomaceous earth). If using DE, replace often because it will harden on the surface rendering it useless. Traps left in the hive for long periods of time tend to get brittle, causing it to crack, which allows bees access and potential drowning in oil. Discard after a couple of months and replace.
Screen bottom board with tray
Although a bit costly, these trays work well to trap and drown/kill beetles that fall off the frames to the bottom of the hive. This trap uses oil or DE like the in-hive traps but under the hive in a tray. The oil in this trap will go bad within a few weeks so keep a schedule to change it often. Likewise, DE (diatomaceous earth) will crust over negating the kill property of the product. Simply use your hive tool to break up the upper crust, exposing fresh DE underneath – in turn reactivates the trapping benefit.
Disposable cloth sheets
Probably the easiest of all methods, a type of disposable cloth sheet purchased at a bee supply. It is either laid across the top bars as one whole sheet or cut into strips and placed in the corners of the hive where SHB roam. Inventive beekeepers also use “spent/used” dryer sheets or sweeping sheets – any product used (not packaged for in hive use) should be free of scents and cleaning agents. How it works - the sheets become fuzzy as they are “scuffed up” by the bees and the beetles become stuck when they try to hide or crawl across them. Sometimes a few bees can also become stuck and die with the beetles in these traps. Remove and discard after a few weeks. Beyond physical barriers and traps, there are also chemical and biological methods of control. These are treatments designed exclusively for use outside the hive and rely on the interruption of the SHB life cycle by targeting the larvae as they enter the ground to pupate.
An insecticide purchased as a concentrate, which is mixed with water (as directed in the label’s instructions) and poured on the ground around the hive. Beekeepers should be very careful to keep this insecticide from getting on the hive or contaminating any water supply as it is deadly for bees and other pollinators.
Used as an organic method of pest control, and also applied with water to the ground around hives. Nematodes are living creatures that thrive in specific conditions and should be introduced to the soil as soon as possible after purchase. The ground should be moist and watered again after application to help the nematodes move in the desired area. Once they are in the soil, they will enter any beetle larva they find, causing death within about 48 hours. Keep in mind there are many types of beneficial nematodes. Look specifically for Heterorhabditis indica (H. indica) and the conditions they need to be used effectively.
Ultimately, nothing surpasses the strength of the colony as a deterrent against a hostile takeover by any pest – and small hive beetles are no exception! They are opportunistic invaders that can travel with swarms and live within a hive for months. They have even developed a method to trick the bees into feeding them!
Despite our best efforts, beekeepers cannot control all the factors that affect the health and strength of a hive; but knowing how to control and reduce the impact of these beetles will increase your confidence to make a difference at a critical time resulting in success instead of a yucky mess!