Large Garden Bumblebee

Bombus ruderatus

Summary 6

Bombus ruderatus, "large garden bumblebee".
Body lengths (from different sources):
Queen 22mm, worker 16mm, male 15 mm
Queen 21-23mm, worker 11-18mm, male 15-16mm

Distribution: Sub-alpine regions of both islands.

Has a long face and tongue; these are adaptations for feeding on long-tubed flowers (eg red clover, foxgloves).

They are black, with two yellow bands on the thorax (front half of body), a single thin yellow band on the abdomen (rear half of body) and a white tail.
Has a long face/head when viewed from the front.
It usually nests underground.

Classed with B. hortorum as sub-genus Megabombus, it is difficult to visually distinguish some individuals of the two species, see http://www.nhm.ac.uk/research-curation/research/projects/bombus/Williams&Hernandez00_ruderatus.pdf .

A suggested visual difference from B hortorum, is that the yellow band on the scutellum (the band to the rear of the wings) is very broad, about the same width as the yellow band at the front (head end) of the thorax. In B. hortorum, the yellow band is much thinner.

http://www.nhm.ac.uk/research-curation/research/projects/bombus/_key_colour_british/ck_local_s.html#ruderatus :
The white hairs of the tail extend further foward at the sides of the abdomen tahn in the middle.

Another suggested difference is that B. ruderatus thorax hairs are of equal length, giving the impression of a much 'neater', 'velvet' short-haired appearance.

In the NZGEO article of Oct-Dec 1994 the differences were described as "The yellow waist of ruderatus is more clearly defined than that of hortorum, which blends more gradually with the surrounding black, and ruderatus stripe colour can vary from yellow through to black, but hortorum is always lemon-yellow".

Sources and Credits

  1. (c) Tony Wills, some rights reserved (CC BY-SA), uploaded by Tony Wills
  2. (c) Hectonichus, some rights reserved (CC BY-SA), http://commons.wikimedia.org/wiki/File:Apidae_-_Bombus_ruderatus.JPG
  3. (c) sea-kangaroo, some rights reserved (CC BY-NC-ND), uploaded by sea-kangaroo
  4. (c) Maurice, some rights reserved (CC BY-NC), uploaded by Maurice
  5. (c) Tony Wills, some rights reserved (CC BY-NC-SA), uploaded by Tony Wills
  6. Adapted by Tony Wills from a work by (c) Wikipedia, some rights reserved (CC BY-SA), http://en.wikipedia.org/wiki/Bombus_ruderatus

More Info

iNaturalist NZ Map

Subgenus Megabombus