About the Hive Beetle

DAI-288, Revised June 2005
MJ Fletcher Principal Research Scientist
LG Cook Veterinary Officer, Chemical Control


The Small hive beetle, Aethina tumida (Murray) (Coleoptera: Nitidulidae) is native to South Africa but is not regarded as a serious pest there. It reached prominence as a pest when it was found in Florida in 1998 and it has now spread to fifteen states in the eastern half of the United States where it sometimes does serious damage to beehives. The pest was confirmed in beehives in the Sydney region in October 2002. It is thought that the Small hive beetle (SHB) will thrive in tropical, semi-tropical and temperate climates although there is little confirmatory information on this available.
The larvae contribute to hive death and damage stored hive materials, though damage seen locally has been minimal. They feed on live brood and honey and their excrement contaminates the honey, causing fermentation.

IDENTIFICATION


The adult beetle, which is the stage most commonly seen, is black or dark brown, ovoid in outline and about 5-7 mm long (Figure 1). They have clearly clubbed antennae and wing cases (elytra) shortened so that the apical few segments of the abdomen are visible (Figure 2).
In general, the adult beetles are about one third the size of a worker honeybee. The adult beetles lay small elongate whitish eggs in clumps in beehives. The eggs are smaller than honeybee eggs but similar in shape and colour.

The larvae grow to 10-13 mm long, cigarshaped and pale whitish cream (Figure 3). Their most distinctive feature is the presence of two rows of short spines along the centre of the back, with the last two projecting beyond the rear end of the larva (Figure 4). When fully grown, the larvae enter the soil in front of and beneath the hive to pupate. The SHB larva should not be confused with the Wax moth larva, which has a number of prologs (see Figure 5) in addition to its thoracic legs and also spins web or cocoons.

Other beetles in the family Nitidulidae include Carpophilus species (the dried fruit beetles) and Aethina concolor (the hibiscus flower beetle), a very common species in hibiscus and magnolia flowers. These species differ from A. tumida in size and shape and, in Carpophilus species at least, in coloration.

HOW TO CHECK YOUR BEEHIVES


The steps below outline the method by which a beekeeper should inspect hives for the presence of SHB. Note that beetles will move quickly away from the light when the hive lid is opened.
  1. Initially, remove the lid and place it on the ground upside down. Place the super on top of the lid and leave it for about a minute. Lift the super off the lid and quickly look for beetles, which will have moved onto the lid away from the light.
  2. If no beetles are seen, remove brood combs one at a time, examine all surfaces and place each frame outside the hive. Continue until all frames have been examined and the brood chamber is empty.
  3. Examine the floor of the brood chamber, particularly looking in the rear corners of the bottom board where the beetles will hide from the light.
  4. If the bottom is not attached, remove the brood chamber and examine the bottom board. Again, the beetles will tend to run away from the light, so be quick.
  5. Pick up the beetles either using fine-tipped tweezers or in your fingers. Place the beetles in a sealed container and put them in a freezer overnight to kill them.
  6. Supers/frames held for extraction could be infested with larvae - check them too

SPREAD OF SHB


While the beetle is spread mainly by the movement by beekeepers of beehives and bees, direct spread by flying beetles up to seven kilometers has now been seen in Australia.

The beetle pupates in the soil, so the movement of soil from apiary sites could possibly spread infestation.

Wherever possible, contaminated hives should not be placed within 5-10 kilometres of other hives, to protect the uncontaminated hives from infestation by flying beetles. Weak hives and larger apiaries are more attractive to beetles. The life cycle and multiplication of the beetle can be disrupted by appropriate treatments.

LIFE CYCLE OF SHB


Adult beetles live primarily in the hives, where they feed on bee eggs, pollen and rubbish within the hive. They lay their eggs, usually out of the way of bees, within hives. These eggs, which are 1.2 mm long and white, can be found anywhere in a hive - including on wax - and are difficult to find. The eggs usually hatch into larvae after 2-4 days, but up to 6 days is reported.

Larvae grow in the hives and mature by 21 days at most. They feed on pollen and brood in particular, but burrow through wax and can feed on, and contaminate, honey as well. The mature larvae are attracted to light and leave the entrance of the hive to find soil in which to pupate. They burrow up to 200 mm deep into the soil, depending on the soil type. They prefer soft, sandy soil. In the USA, 100% of pupating larvae have been found within 900 mm of the hive. Not all larvae leave the hive - pupae can be found lodged in hives or stored material as well as soil.

Most pupae hatch and beetles emerge within 60 days unless conditions are very cold (up to 100 days at less than 10°C). Emergent beetles are pale yellowish brown at first but darken quickly. They fly readily and are attracted to light.

Beetles are strongly attracted to bees (even more so than hives/honey/pollen) and enter nearby hives where they feed. Beetles can fly well but technical detail on this is scarce. They are reported overseas as travelling with swarming bees. Adults can survive only about 5 days without food or water, but when removed from hives can complete a life cycle on various tropical and other fruits, including rockmelon, but this is not considered important in their spread.



Agdex 481/20 ©State of New South Wales (2005) Industry & Investment NSW | Primary Industries The information contained in this publication is based on knowledge and understanding at the time of writing (December, 2004). However, because of advances in knowledge, users are reminded of the need to ensure that information upon which they rely is up to date and to check currency of the information with the appropriate officer of New South Wales Department of Agriculture or the user´s independent adviser.

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