Introduction of the large earth bumblebee (Bombus terrestris) - key threatening process listing

The Scientific Committee, established by the Threatened Species Conservation Act, has made a Final Determination to list the Introduction of the Large Earth Bumblebee, Bombus terrestris (L.), as a KEY THREATENING PROCESS in Schedule 3 of the Act. Listing of key threatening processes is provided for by Part 2 of the Act.

NSW Scientific Committee - final determination

The Scientific Committee has found that:

1. The Large Earth Bumblebee, Bombus terrestris (L.) (Hymenoptera: Apidae), is a relatively large, primitively eusocial bee native to Europe. Bombus terrestris is generally more heavily built and hairier than the honeybee, Apis mellifera L.. Large Earth Bumblebee queens are 30-35mm long; workers are more variable in size, ranging from 8-22mm long; and males are similar in size and appearance to large workers. Large Earth Bumblebees 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.

2. In cool climates Large Earth Bumblebees form annual colonies and new colonies are initiated each spring by mated solitary queens. Colonies quickly reach sizes of 300 to 500 individuals. In warmer areas colonies may reach large sizes, with colonies of more than 1000 individuals being recorded in Tasmania (Buttermore 1997).

3. Large Earth Bumblebees were first recorded in Tasmania in 1992 and have since spread over a large area of the state in both urban and native bush areas (Hingston et al. 2001). This species of bumblebee forages from a wide range of plant species. In Tasmania it has been recorded foraging from at least 170 plant species (156 exotic, 14 native; Semmens 1996) and in New Zealand it has been recorded visiting 400 species of exotic plants (Low 1999).

4. Colonies of Large Earth Bumblebees have become established throughout Tasmania in a wide range of habitats from sea level to 1250m altitude within all the major native vegetation types (Hingston and McQuillan 1998). This demonstrates the potential of the species to naturalize in NSW climatic conditions.

5. At present this species is not known to occur in NSW, but could establish through accidental introduction from colonies in Tasmania or New Zealand, or deliberate introduction as a pollinating agent.

6. Large Earth Bumblebees are specialist pollinators 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. The presence of the Large Earth Bumblebee may also disrupt pollination of native plant species (Hingston and McQuillan 1998).

7. Scotch Broom, Cytisus scoparius, is currently a weed of concern in NSW, particularly in the Barrington Tops area. In other parts of the world, e.g. USA, New Zealand and its native Europe, this species is pollinated by Large Earth Bumblebees. On mainland Australia, Scotch Broom is pollinated by honeybees, but at a lower efficiency than has been reported for Scotch Broom pollinated by Large Earth Bumblebee (Simpson 2002). It is likely that, should Large Earth Bumblebees be introduced into NSW, there will be an increase in seed-set in Scotch Broom and other exotic species that require Large Earth Bumblebees for pollination which will, in turn, lead to an increase in the populations and weediness of these plant species.

8. Species and populations in NSW that may become threatened by the presence of Large Earth Bumblebees promoting the spread of Scotch Broom include endangered species Epacris hamiltonii, the Bathurst Copper Paralucia spinifera, the Ben Halls Gap National Park Sphagnum Moss Cool Temperate Rainforest Endangered Ecological Community, and the vulnerable terrestrial orchid Chiloglottis platyptera.

9. In view of the above the Scientific Committee is of the opinion that the Introduction of the Large Earth Bumblebee, Bombus terrestris, could cause species or populations that are not threatened to become threatened.

Associate Professor Paul Adam
Scientific Committee

Proposed Gazettal date: 13/2/04
Exhibition period: 13/02/04 - 26/03/04

Buttermore RE (1997) Observations of successful Bombus terrestris (L.) (Hymenoptera: Apidae) colonies in southern Tasmania. Australian Journal of Entomology 36, 251-254.

Hingston AB, Marsden-Smedley J, Driscoll DA, Corbett S, Fenton J, Anderson R, Plowman C, Mowling F, Jenkin M, Matsui K, Bonham KJ, Ilowski M, McQuillan PB, Yaxley B, Reid T, Storey D, Poole L, Mallick SA, Fitzgerald N, Kirkpatrick JB, Febey J, Harwood AG, Michaels KF, Russell MJ, Black PS, Emmerson L, Visoiu M, Morgan J, Breen S, Gates S, Bantich MN, Desmarchelier J M (2001) Extent of invasion of Tasmanian native vegetation by the exotic bumblebee Bombus terrestris (Apoidea: Apidae). Austral Ecology 27, 162-172.

Hingston AB and McQuillan PB (1998) Does the recently introduced bumblebee Bombus terrestris (Apidae) threaten Australian ecosystems? Australian Journal of Ecology 23, 39-549.

Low T (1999) Feral Future. pp 304-306. Viking (Penguin Books): Melbourne.

Semmens TD (1996) Flower visitation by the bumble bee Bombus terrestris (L.) (Hymenoptera: Apidae) in Tasmania. Australian Entomologist. 23, 33-35.

Simpson S (2002) The reproductive ecology of Cytisus scoparius (L.) Link (Fabaceae): an invasive weedy species infesting Barrington Tops NSW. Unpublished B.Sc.(Hons) thesis, Ecosystem Management, University of New England.