Small Hive Beetle

Please contact apiary@ontario.ca for the report in PDF format.

Introduction

The small hive beetle (SHB), Aethina tumida, is an invasive pest of the European honey bee. The SHB can impact colony health and damage beekeeping equipment. When SHB is suspected in an apiary, beekeepers must report this to the Ontario Ministry of Agriculture, Food and Rural Affairs' Apiary Program.

Spread of Small Hive Beetle

The SHB is native to sub-Saharan Africa and has spread to many regions of the globe. The SHB was first discovered in North American in 1998 and has become well established in most states across the USA, with particularly large populations in warmer, coastal states.

In Canada, the SHB was first discovered in Manitoba in 2002. Since then, SHB has also been detected in British Columbia, Alberta, Ontario, Quebec and New Brunswick.

Life Cycle and Biology

The SHB is a member of the "sap beetle" family Nitidulidae. Like other beetles, the SHB goes through complete metamorphosis from egg to larvae to pupae to adult. The timing of full development varies from 21 to 94 days depending on environmental conditions such as the local temperature and humidity.

Adult SHB will seek out honey bee colonies for shelter, food and breeding area for their developing young. The eggs of the SHB are small (1.4 x 0.26 mm), pearly white and are laid in clusters in cracks and crevices of the hive. Eggs hatch in three to six days.

Larvae grow to 11 x 1.6 mm before pupation. Larvae resemble grubs and are white to beige in color with a brown hardened head, three sets of legs and rows of brown spines along the length of the body (Figure 1). Larvae are typically found clustered together in cells of the honey comb, often immersed in a film of fermented honey.

The larvae are the most destructive life stage of the SHB in terms of damage to honey bee colonies. Larvae feed on honey bee brood, pollen, honey and tunnel through wax comb consuming protein required for their development. Larvae defecate in the honey comb, causing the honey to ferment and spoil.

After an average of 16 days (may range from 10 to 28 days) the larvae will leave the colony and burrow into the soil to pupate for an average of 25 days (may range from 10 to 60 days). On average, larvae will burrow 10cm deep and approximately 30 cm from the colony entrance. Lighter, sandier soils are most suitable for SHB pupation.

Adult SHB are reddish brown to black and measure 4 to 7 x 2 to 3.5 mm. Adult SHB can be identifed by clubbed antennae, shortened wing coverings that do not extend the full length of the abdomen and a distinct crescent moon shaped structure behind the head (Figure 2).

Adults may live up to six months, can disperse approximately 10 to 14 km by flying and have a tremendous reproductive capacity. The dispersal of adults is aided by the movement of infested honey bee colonies and beekeeping equipment. SHB are not restricted to honey bee colonies as they can survive on rotting fruit and can go without food for up to 10 days in the adult stage. The adult SHB can overwinter in the honey bee cluster.

Small hive beetle larvae

Figure 1. Small hive beetle larvae

Small hive beetle adult

Figure 2. Small hive beetle adult

Impact

Weakened and compromised honey bee colonies are at greatest risk of SHB damage. However this may also include healthy nucleus colonies, mating nucs and queen banks. A honey bee colony without a strong population of worker bees to protect the exposed food stores and bee brood can succumb to a rapid increase in numbers of SHB larvae. This will further stress the colony as the SHB larvae will feed on brood, spoil food stores and foul the environment of the colony.

In severe SHB infestations, colonies may perish or abandon the hive. Although adult SHB may be present in strong, populous colonies; the development of large numbers of SHB larvae is often restricted by the activities of the honey bee workers.

In dead honey bee colonies or exposed beekeeping equipment, SHB infestations can increase dramatically as there is an unprotected food source available to SHV larva. In honey houses and extracting facilities, SHB can spoil honey when honey comb is exposed for long periods of time.

Detection

Adult SHB are often found in dark, tight spaces in the hive environment. However, they may be encountered anywhere in the colony, especially when present at high densities. Adults are typically found on the underside of the inner cover, tops of frames and on the bottom board. Adult SHB will move quickly away from light, so it is important to make a quick visual scan as soon as the colony is opened.

Adults can also be detected using a variety of traps. Two of the most common traps are corrugated cardboard or plastic inserts and traps containing oil. SHB larvae are typically found on the surface of unprotected comb and at higher densities on the bottom board. Observably symptoms indicating the presence of SHB larvae include clusters of larvae feeding in the comb and fermented honey on the surface of the frame (Figure 3). This can be observed in colonies both in the field and in extraction facilities.

Honey comb infested with small hive beetle

Figure 3. Observable symptoms indicating the presence of small hive beetle larvae in the comb.


For more information:
Toll Free: 1-877-424-1300
E-mail: ag.info.omafra@ontario.ca
Author: OMAFRA Staff
Creation Date: 28 September 2010
Last Reviewed: 3 August 2017