Small Hive Beetles
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.
Hive beetle larvae eat honey, pollen and brood - then in a mass exodus, leave the hive near the second week. If the soil is moist and welcoming, the larvae will pupate in the top 4 inches, typically within about 3 feet of the hive. If the soil is too dry, the larvae may roam over 500 feet in several week's time until they find a favorable location. Weak hives with dwindling populations and honey frames that are undefended are most susceptible to a SHB takeover.
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. Fortunately, beekeepers are always inventing new creative methods to reduce the number of beetles in a hive. Some of the most common deterrents include a variety of physical traps. Screened bottom boards with trays allow the beekeeper to use either vegetable oil or diatomaceous earth (DE) to kill beetles that fall into the bottom of the hive.
There are also disposable and reusable traps that can be filled with oil or DE and placed between the frames. All of these types of traps have small openings that allow the beetles to run inside while keeping the bees out. A different style of trap, and probably the easiest of all methods described in this article, is a type of disposable cloth sheet that is cut into strips and placed in the hive where SHB roam. The cloths can come in a variety of similar materials and are called by several names such as dryer sheets, sweeping sheets, and beetle sheets – all of these products used in the hive should be free of scents and cleaning agents. The sheets become fuzzy as they are “scuffed up” by the bees and the beetles become stuck when they try to hide in them. Sometimes a few bees can also become stuck and die with the beetles in these traps.
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. A permethrin drench is an insecticide purchased as a concentrate, then is mixed with water (as directed on the label’s instructions) and poured on the ground around the hive. Beekeepers should be careful to keep this insecticide from getting on the hive or contaminating any water supply as it is deadly for bees and other pollinators. Beneficial nematodes are also applied with water to the ground around hives and can be used as an organic method of pest control. Nematodes are actually live 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!
By: Nantte Davis
Texas Master Beekeeper