Eggs are laid in irregular shaped masses on the combs. Larvae can be confused with wax moth larvae but beetle larvae have only six legs. Wax moth larvae have more than six legs and they are found along the length of the larvae. Beetle larvae have spines on the upper or dorsal part of their body.

Beetle larvae change to pupae and do not spin webs or cocoons. They change to a whitish brown pupae generally in the soil near the hives.

The adult is a small brown-black beetle 5 to 7 mm long and 2.5 to 3.5 mm wide. Freshly emerged adults may be red but soon become dark brown to black.

Adult beetles can live as long as six months with a generation being completed in 5 to 12 weeks.

Damage

Beetle larvae burrow and tunnel through combs consuming brood, pollen and honey. As they do this they produce a repellent slime so bees do not remove the beetle larvae. Combs are damaged and drip honey which then ferments.

Combs full of honey waiting for extraction can be rendered useless as the beetle larvae tunnel, defecate and produce slime over them.

Detection

Beetles are fast moving when the lid is opened. They prefer the dark parts of the hive so the best place to look for them is in the back corners of the bottom of the brood box.

Remove brood combs and the beetles should be in the back corners. If the honey super is left on the upturned lid for a few minutes, beetles usually migrate to the lid where they can be observed on removing the honey super.

Life Cycle

Adult females lay their large egg masses along crevices and cavities on or near beeswax combs, and the eggs hatch in a few days producing a great number of small larvae. The larvae consume pollen and wax but also will eat honey, bee eggs and larvae.

They complete their larval stage in 10 to 16 days and then drop to the ground where they pupate in the soil. The larvae make smooth-walled earthen cells in which to pupate. The cells are sometimes connected by tunnels. The time spent in the soil can vary from 15 to 60 days but the majority of the beetles will emerge as adults after approximately 3-4 weeks. Dr. Lundie reported that in his laboratory study most of the larvae that entered the soil to pupate, emerge as adults and the ones that did not emerge appeared to have been killed by a fungus.

It would appear that the beetle larvae do not travel very far from the hive to pupate, as the majority are found within 90 cm from the hive entrance (mostly within 30 cm) and only 20cm deep (10 cm in sandy soil).

The males are the first to leave the soil and are suspected to be responsible for attracting females using aggregation pheromones.

The females are capable of laying eggs approximately one week after emerging from the soil.

Stanghellini et. al. (2000) estimated that a single female could lay between 200 and 400 eggs.

Spread

It is possible that this beetle follows honey bee swarms.

Small hive beetles can fly up to 5 kilometres, but there is unconfirmed information that they may fly further. Eggs of small hive beetle have been observed attached to worker bees in Florida, USA (Elzen et al, 1999). Spread by queen bees and escorts in mailing cages is not high risk.

All beehives, bee equipment, combs and supers (full or empty), wax cappings and bee collected pollen can house and therefore spread the beetle.

Soil on pallets can spread the pupae and hence the beetle.

Fruit

Eischen et al, (1999) demonstrated that small hive beetle could feed, apparently develop normally and complete all life-cycle stages on fruit such as avocado, rockmelon and grapefruit. They speculated that adult small hive beetles prefer and seek out honey bee colonies, but when this food source is scarce they will feed and complete their life-cycle development on certain fruit. Small hive beetles also fed on bananas, pineapple, grapes and mango.

Control

To date, there is no adequate solution to remove this pest from hives.

Freezing the equipment for 24 hours after reaching -12°C, kills all stages of the small hive beetle (Hood 1999).

Several forms of trap (filled with attractants) are being trialed, however these must be monitored, cleared and refilled on a regular basis.

Reduction of the hive entrance may assist the bees limit the beetle from entering the hive.

The beetles respond to hive odours released during hive manipulation - eg the scent of honey and wax, so reducing the time the hive is open may assist.

As the beetle must pupate in the ground (and usually with 30 cm of the hive entrance) spraying the ground with a pesticide may limit the spread. The climate and nature of the soil are also important - sandy coastal soils provide a good habitat, while dry western areas seem to be beetle free.

The Qld DPI trialled a trap, and needed to reduce access to the trap. They used a domestic kitchen "place mat" with a furry (Velcro style) lower surface. As the beetles tried to traverse the mat, their segmented legs were tangled in the nylon loops, and 80% of the beetle caught, remained trapped on the mat.

Research is continuing on many fronts. One by Dr Garry Levot of NSW DPI using the insecticide fipronil on a treated cardboard insert. In the 2006 trial, it proved 99% successful after 6 weeks, with post-treatment samples less than 1 ppb.

Resources :

Canadian Honey Council

Australian Honey Bee Industry Council

Beedata - Apis UK