Bombus terrestris
(bumble bee)

This species is native to the western Palaearctic region (central and southern Europe, North Africa, Madeira and the Canary Islands, east to Afghanistan). It is found in all the countries around the Mediterranean Sea except Egypt (Rasmont et al., 2008) and extends to the north up to the latitude of Helsinki and east to Altai (Pekkarinen and Kaarnam, 1994). Bumble bees are highly valued pollinators worldwide and substantially add to the value of crop production (Goulson, 2003a). B. terrestris has been introduced into New Zealand (e.g. Gurr, 1957; MacFarlane and Gurr, 1995), Tasmania (Cardale, 1993; Stout and Goulson, 2000), Brazil (Thorp, 2003), Chile (Torretta et al., 2006), Mexico (Stout and Goulson, 2000; Winter et al., 2006), and Japan (Washitani, 1998; Inoue et al., 2008). It appears that it was also introduced into mainland Australia (New South Wales) without persisting (W. Froggatt in Franklin, 1913). Recently it has spread from Chile to Argentina (Torretta et al., 2006).

B. terrestris is not considered invasive in its ‘native’ range. Following recent establishment, B. terrestris is considered by some to be invasive in Japan and Tasmania, Australia (which has no native bumble bees) (Winter et al., 2006; Hingston, 2006; Ings et al., 2006). Australia, USA and Canada are prohibiting the import of B. terrestris. China, South Africa, the Canary Islands and Norway, do not allow B. terrestris to be imported either (Velthuis and van Doorn, 2006; Winter et al., 2006); the Japanese government has included B. terrestris in its Invasive Alien Species Act (Velthuis and van Doorn, 2006). In New South Wales (Australia), the alteration of natural pollination dynamics caused by the presence of B. terrestris in other countries has prompted its listing as a “Key Threatening Process”, and in Victoria, Australia, it is listed as a “Potentially Threatening Process”, and B. terrestris importation is also prohibited in all states.

B. terrestris is widely distributed in the western Palaearctic region. Its distribution is typically Mediterranean, extending from the Canary Islands in the west, to the Altai in the East, and from the Anti-Atlas Mountains of Morocco in the south to southern Finland in the north (Rasmont, 1983; Estoup et al., 1996; Rasmont et al., 2008). B. terrestris is found to the latitude of Helsinki and east to the Altai, from ca. 30° to 60° N (Pekkarinen and Kaarnam, 1994). It is not found in Egypt and is absent from high alpine levels, the deserts and the arid, sub-desertic steppes (Rasmont et al., 2008). Within its wide distribution, there are important subspecific differences in morphological characters (e.g. coat colour and behaviour, learning performance), which underline the genetic differentiation among subspecies (Coppée et al., 2008).

There are other dangers associated with commercial trafficking of bumble bees. B. terrestris is now naturalised in several countries where it was first introduced for pollination of greenhouse crops. There are substantiated concerns regarding possible competitive effects of this species on native bumble bees and other native pollinators, which may in turn reduce the reproductive capacity of native plants (Hingston et al., 2002). Studies have shown that B. terrestris has four times the reproductive output of native species in Japan (Matsumara et al., 2004) and that there are considerable overlaps in forage use and timing of foraging (Inari et al., 2005). Some greenhouses are not secure and a recent study in Canada found that 73% of pollen carried by workers returning to commercial colonies originated from plants outside the greenhouse (Morandin et al., 2001; Whittington and Winston, 2004). B. terrestris was allowed into Mexico in 1995 and 1996 without the knowledge of the USA or Canadian regulatory agencies (Flanders et al., 2003). These bumble bees were infected with the microsporidian Nosema bombi, an internal parasite of bumble bees, prompting the destruction of the colonies intended for Jalisco, Mexico, and a retraction of import permits (Winter et al., 2006). The use of B. terrestris for greenhouse production in Mexico has since been replaced by Bombus impatiens, with up to 55,000 colonies sold per year (Velthuis and van Doorn, 2006), since importation by Koppert de Mexico in 2001 (Martinez Guzman, 2005).

Bumble bees are among the most important pollinators of temperate zone plants because of their diverse body and proboscis sizes, ability to sonicate, dense pile, long activity periods, and adaptability to a wide variety of temperatures and climate types (Winter et al., 2006). Bumble bees are adapted to a diversity of climates and habitats, and are active even when light intensity is low. Due to their relatively large body sizes and dense pile, they are able to continue foraging even at temperatures as low as 10°C and as high as 32°C, with observations of Bombus terrestris dalmatinus at temperatures as low as 2°C (Winter et al., 2006). Their increased motility allows them to continue flower visits for most of the year, unlike honeybees, which are mostly inactive at temperatures below 16°C (Heinrich, 1979). Bumble bees can forage during adverse climatic conditions, even flying during light rain, visiting from 20-50 flowers per minute with high pollination efficiency.

Bumble bees are second only to honeybees as commercial pollinator insects. B. terrestris is a specialist pollinator of a number of European plant species, either because they require a bee of a certain size (e.g. foxglove, Digitalis spp.), weight (e.g. Scotch broom, Cytisus scoparius), or require buzz pollination to release pollen from poricidal anthers (e.g. many Solanaceae). This may facilitate an increase in the abundance and distribution of weed species in countries where European plants have been introduced. The presence of B. terrestris may also disrupt pollination of native plant species (Hingston and McQuillan, 1998).

Genetics

Environmental

• Commercial pollinator

B. terrestris is a relatively large, primitively eusocial bee native to Europe. B. terrestris is generally more heavily built and hairier than the honeybee, Apis mellifera. B. terrestris queens are 30-35 mm long; workers are more variable in size, ranging from 8-22 mm long; and males are similar in size and appearance to large workers. B. terrestris are black with one yellow or ochre band across the front of the thorax and a second yellow or ochre band across the abdomen. The tip of the abdomen is either buff or white.

The world bumble bee (Bombus) fauna consists of approximately 250 known species; most of them are found in temperate parts of the northern hemisphere. Several distinct populations occur in the natural range of B. terrestris that show distinct colour and size variations (Chittka et al., 2004; Rasmont et al., 2008). Genetic studies have shown that several distinct subspecies exist, some of which can be considered as distinct species altogether. Examples include populations from Sardinia hosting Bombus terrestris sassaricus, the Canary Islands with Bombus terrestris canariensis, and the British Isles with Bombus terrestris audax (Estoup et al., 1996; Widmer et al., 1998). Rasmont et al. (2008) recognise nine morphological subspecies in B. terrestris: ssp. terrestris; ssp. africanus (North Africa), ssp. audax (British Isles), ssp. calabricus (Italy and Sicily), ssp. canariensis (Canary Islands), ssp. dalmatinus (Balkans, Urals and Asia), ssp. lusitanicus, ssp. sassaricus (Sardinia) and ssp. xanthopus (Corsica). For taxonomic differences and distribution within subspecies see the papers from Widmer et al. (1998); Rasmont et al. (2008); Coppée et al. (2008); the website of the Natural History Museum, London devoted to bumble bees (http://www.nhm.ac.uk/research-curation/research/projects/bombus/bo.html) and Professor David Goulson’s (Stirling University) webpage (http://www.sbes.stir.ac.uk/people/goulson/index.html).

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Invasive Species Management

There is no known control of B. terrestris once it has been introduced and/or has escaped in the natural environment. The only management strategy is through exclusion and restriction of importation into new areas or countries where it is not endemic and can impact on the local environment. Currently the best option is to promote the commercial use of native bumble bees within their countries of origin, rather than import the exotic species (B. terrestris) with the potential for damaging consequences. 

27/07/10 Original text by:

CRCNPB Australia, CRC for National Plant Biosecurity, Canberra, Australia