The large earth bumblebee (Bombus terrestris) is a European bee, found in Tasmania but not on the mainland, that competes with native bees and birds for nectar, and benefits weeds by pollinating their flowers.
Photo: Alvesgaspar | CC BY 3.0
Identification
Bumblebees at flowers stand out as much plumper and furrier than honeybees, and they are usually larger. There are no native insects that resemble this species. Notable features are the extreme furriness, and the bands in three colours: black, yellow (or ochre) and white. The queen bees differ in having a rear end that is buff rather than white.
Large earth bumblebees are an invasive species in Tasmania, that should be kept out of the mainland. They could arrive on ships or planes coming from Tasmania, or from New Zealand, which also has them.
Large earth bumblebee. Photo: Arnstein Staverløkk, Norsk Institutt for Naturforskning
Size
Bumblebee workers are 8-22 millimetres long, and queens can be 25 millimetres long. (Honeybees 11.5-13 millimetres long.)
Behaviour and location
Bumblebees attend flowers of garden plants, weeds and native plants. If one is seen briefly, others may be seen on the same flowers. They use those of eucalypts, banksias, tomatoes, foxgloves and agapanthus, among others.
They nest in burrows in the ground and in crevices and may be seen entering or leaving these. Nests can be in compost heaps, grass clippings, woodpiles, drains, cavities under concrete slabs and in old stuffed sofas.
These are a temperate bee that is unlikely to survive north of Brisbane.
Similar species
Female carpenter bees (Xylocopa aruana and X. lieftincki) are so big and furry they are sometimes confused with bumblebees, but they lack bands, and their abdomens lack long hairs. A female is shown here. Males are yellow-brown or olive. Both species look much the same. They occur in northern and eastern Australia, south almost to Sydney.
The teddy bear bee (Amegilla bombiformis) is plump and furry, but also has different colours from the large earth bumblebee. One is shown here only to make the point that the large earth bumblebee is easy to recognise.
Carpenter bee (X. lieftincki) Ken Walker, Museum Victoria
Teddy bear bee. Photo: Louise Docker | CC BY-SA 2.0
Safe collecting
Because bumblebees return to clumps of flowers, it is often possible to obtain photos by waiting beside these once a bee has been spotted. One can be collected with a net, or by lowering a jar or plastic bag over it while it is busy at a flower.
Be careful because bumblebees can sting multiple times. A bee that has been caught can be killed by placing it in the freezer and then photographing when it has thawed.
Who to tell
Think you’ve found large earth bumblebees?
Large earth bumblebees are common in Tasmania, so sightings made there are not significant.
If you see one on the mainland, that is very concerning. Do not contact the Invasive Species Council, phone the Exotic Plant Pest Hotline: 1800 084 881. You will be put in touch with the Department of Primary Industries or Agriculture in your state or territory.
If you do not receive a satisfactory response email us via our contact form.
The problem
Bumblebees compete with native pollinators. In Tasmania they feed readily on the flowers of blue gums (Eucalyptus globulus) and black gums (E. ovata), which are the main breeding-season foods of the critically endangered swift parrot. The national recovery plan for the swift parrot mentions bumblebee competition, and the risk of bumblebees spreading to the mainland – where swift parrots feed in winter – as a threatening process. Research on swift parrot habitat around Hobart shows that bumblebees reduce nectar yields on these trees. On one black gum studied, they made up more than 90% of visitors to the flowers.
Another risk of bumblebees is their potential to worsen weed problems by serving as superior pollinators for northern hemisphere plants adapted for bumblebee pollination. Scientists have noted ‘clear evidence for a positive link between the spread of weeds and the presence of introduced bees’. Bumblebees are desired crop pollinators for tomatoes and capsicums because they are better than honeybees at moving pollen between the flowers of these plants, and that holds true for some weeds as well. Australia has many plants with the potential to become serious weeds that are currently minor weeds or not weeds at all because they lack the bumblebee pollinators with which they evolved. Also, major weeds such as blackberry (Rubus fruticosus), foxglove (Digitalis purpurea), gorse (Ulex europaeus), Paterson’s curse (Echium plantagineum) and broom (Cytisus scoparius) could benefit from pollination by bumblebees.
As well as Tasmania, this bumblebee has established in Japan, Chile and Argentina, escaping from greenhouses where it is used for crop pollination. In Japan it outnumbers native bumblebees in some settings, and is blamed for a decline in one native species (B. hypocrita sapporoensis).
Beekeepers are concerned about the prospect of bumblebees reducing yields in honeybee hives by competing for nectar.
Further information
- Invasive Species Compendium: Bombus terrestris datasheet.
- Aussie Bee: What harm could exotic bumblebees do in Australia?
- Invasive Species Council: Tasmanian bumblebee decision defies evidence.
- Aussie Bee: Proposal to import Bombus terrestris onto mainland Australia for crop pollination purposes.