The small hive beetle Aethina tumida is a parasite of honey bees originating in (Sub-Saharan) Africa. This parasite has become highly invasive, and has multiplied in various countries since 1996. It has managed to establish itself in the USA and Australia, where it has caused substantial damage in honey-bee colonies. Although its initial incursion into Europe was prevented in 2004, it was discovered in southern Italy in 2014. Measures have been taken to prevent its spread, with the importing of bees from infected regions now being prohibited in the EU and Switzerland. A monitoring programme, Apinella, has been set up in Switzerland to detect the beetle's possible presence as quickly as possible, thereby increasing the changes of its eradication.
The small hive beetle, Aethina tumida, is a parasite and scavenger of social bee colonies, which is native to regions of Africa that are South of the Sahara. It has become an invasive species and has been recorded in a number of countries outside its natural range since 1996. In the USA and Australia, it has managed to establish populations and can cause considerable damage to local honeybee, Apis mellifera, colonies. It is now established since 2014 in South of Italy. In contrast to V. destructor, the small hive beetle is not only dependent honey bee colonies for his survival. He can feed and reproduce on fruits for example. In the hive beetles consume honey, pollen and brood. The females lay their eggs in areas out of reach of honey bee mandibles. It is the larvae emerging from these eggs that damage the colonies. They contaminate the honey with bacteria and fungi they carry, which results in a fermentation process. Before pupation, the larvae leave the hive and burry themselves in the ground. Their further development depends on soil quality and temperature. The adults emerging from their pupation chambers take flight and search for food sources (fruits or honey bee colony) as well as for a mate. More details on the lifecycle of the small hive beetle are to be found in the brochure published by the European Reference Laboratory and on the website of the Honey bee Health Service.
Der Kleine Beutenkäfer (German) (PDF, 852 kB, 15.02.2017)
P. Neumann, W. Ritter (2004)
Biologie, Diagnostik und Kontrolle des Kleinen Beutenkäfers (Aethina tumida, Coleoptera: Nitidulidae) (German and French) (PDF, 1 MB, 15.02.2017)
P. Neumann (2003)
Small hive beetles mate in the hive. During mating, the slightly smaller males rides the female for a long periods (Photo: J. Drescher)
After mating, female beetles typically lay egg clutches hidden in cracks or directly on combs. Beetle eggs are about 2/3 the size of honey bee eggs (Photo: P. Neumann).
Hatching larvae are the most destructive life stage in honey bee colonies. Even relatively strong colonies can be totally destroyed from heavy larval infestations (Photo: M. Schäfer).
After the feeding stage, which can last between 8-29 days, the post feeding wandering larvae leave the colony to pupate in suitable surrounding soil. It leaves a trail of feces and fermented bee products. Wandering larvae have a length of 10-12 mm (Photo: M. Schäfer).
A small hive beetle pupa within a pupation chamber. Depending on soil type, wandering larvae excavate pupation chambers from 5-10 cm beneath the soil surface (Photo: A. Röttger)
Pupation can last between 3 weeks and 3 months depending on environmental conditions (soil humidity and temperature). After pupation, emerging adult beetles leave the soil and disperse over considerable distances to find new host colonies or other food sources and start the life cycle again (Photo: A. Röttger)
Infestation by the small hive beetle constitutes an epizootic disease that must be controlled. Beekeepers suspecting that beetles in a beehive are Aethina tumida must notify the competent cantonal veterinary authority immediately, so that the suspicious case can be examined and the procedure described in the technical guidelines can be applied. Suitable control measures will need to be defined for Switzerland if the beetle manages to establish a viable population in the country.
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Adult small hive beetles in an Elzen et al (1999) cardboard trap. A whole range of trap systems have been developed to catch adult beetles in hives. All trap systems and especially visual hive screenings are comparatively labour intensive when searching for the often well hidden adult beetles. (Photo: P. Neumann)
In order to facilitate diagnosis and to enhance quantitative estimates, we developed diagnostic strips, which are fairly easy to use for apiculturists especially for large-scale operations (e.g. in the US). Application of the diagnostic strips made of corrugated cardboard, which are introduced via the flight entrance. About 30% of adults can be detected after two days in the hive using this approach. (Photo: M. Schäfer)
Conventional control of small hive beetles is achieved via application of chemicals in hives and the surrounding soil. This process introduces risks of beetle resistance, contamination of bee products and undesirable side effects on bees and other non-target organisms. Therefore, analogous to varroa mite control (e.g. using acids), a more sustainable, alternative control is preferred. Initial results using entomopathogenic fungi are promising, but further experiments are required before such methods can be used in conjunction with current apicultural practices.
