Bumblebees in Shetland
Bumblebees
are well known and popular insects. They are larger, more rotund, and more
colourful than honeybees. They are also more friendly than honeybees, and
will only sting when severely molested. As well as their colour, they are
conspicuous by their deep buzzing sound; the scientific name of the `true'
bumblebees, Bombus, means `booming'.
Right
- Shetland Bumblebee Bombus muscorum
In
Shetland, four species of bumblebees are known to occur today. Another
species has been recorded only once, in Bressay in 1926, and is thought to
be extinct; although we cannot be sure. Two of the species which occur in
Shetland are distinct sub-species. The Small Heath Bumblebee (Bombus jonellus vogti) only occurs in Shetland, whilst the distinctive
`Shetland' Bumblebee (Bombus muscorum
agricolae) is a form that occurs in both
Shetland and the Western Isles.
Bumblebees
are not just a colourful part of our insect fauna, they are important
pollinators of certain plant species and, in Shetland, may be a useful
indicator of general environmental quality. For example, the Small Heath
Bumblebee favours better quality moorland, where the heather flowers more
freely. The Shetland Bumblebee also requires high densities of flowers to
maintain a healthy population, so it is seriously affected by overgrazing
and reseeding. The best way to attract bumblebees to your garden is
therefore to plant lots of flowers!
Anecdotal
evidence suggests that bumblebees have declined in Shetland over recent
decades, presumably as a result of changing agricultural practices. SBRC
would like to know much more about the distribution and abundance of
Shetland's bumblebees today, so that we have better baseline data against
which to monitor future changes. We would like to receive all records of
bumblebees in Shetland, to improve our understanding of this fascinating
group.
How to
Identify Bumblebees in Shetland
First of
all, is it a bumblebee? The Honey Bee is not
known to occur naturally in Shetland, although there are several hives
kept on Mainland. A more likely source of potential confusion are certain
hoverflies, which can look extremely similar to bumblebees. If in
doubt, capture the insect in a transparent pot (such as a jam jar) and
look closely at the wings. Hoverflies, being true flies, have only one
pair of wings attached to the thorax, whereas bumblebees have two pairs,
although the hind wings are often `zipped' to the fore-wings in a row of
hooks.
NORTHERN WHITE‑TAILED BUMBLEBEE (Bombus magnus)
This is a
common visitor to gardens and crofting land throughout Shetland, except
Fair Isle. It is the earliest species to appear in Shetland in spring, and
can be seen anytime between April and September. The Northern White-tail
is a very neat, clean-looking species. It has a black thorax with a single
yellow band at the front. The abdomen has another yellow band, and a white
tail; hence this is Shetland's only `double-banded white-tail'.
SMALL HEATH BUMBLEBEE (Bombus jonellus)
The
subspecies vogti is endemic to Shetland. It is a scarce species, closely
associated with heather moorland, and is most frequently seen in July and
August (when heather is flowering). It has a black thorax, with yellow
bands at the front and back. There is a third yellow band on the abdomen,
adjacent to the thorax, and a whitish or buff tail. This is one of two
species of `triple-banded white-tail' in Shetland. However, Small Heath
Bumblebee has a short face, roughly only as long as it is wide (see
diagram below).
Bombus
hortorum
Bombus jonellus
GARDEN
BUMBLEBEE (Bombus hortorum)
Another
scarce bumblebee in Shetland, almost always found around gardens or crops
between June and August, but more widespread than the previous species.
Garden Bumblebee is another `triple-banded white-tail', superficially
similar to the previous species. Apart from where it is found (in gardens
rather than on the hills) it is best told by its longer face,
obviously longer than it is wide (see diagram).
`SHETLAND' BUMBLEBEE (Bombus muscorum)
A common
species, found in a variety of habitats throughout Shetland, between May
and October. The Shetland subspecies
agricolae is also found in the Outer
Hebrides. The Shetland Bumblebee is very distinctive, having a thorax that
is completely orange, which can be seen easily in flight as well as at
rest.
GREAT
YELLOW BUMBLEBEE (Bombus distinguendus)
This is a
species which is presumed extinct in Shetland, with no sightings in the
past 75 years. It is a rare and declining species throughout the UK, most
frequently recorded in north and west Scotland. Bombus distinguendus has
an abdomen which is brownish-yellow all over (i.e. without a distinct
yellow band at the front), while the thorax is similarly brownish-yellow
(rather than yellow), with a black or grey band between the wings. Any
sighting in Shetland would be extremely significant, and would need good
supporting evidence (a photo or a specimen). It should be quickly reported
to SBRC, so that it may be followed up, or confirmed where appropriate.
-
Pictures
- left to right, top to bottom
-
Northern White-tailed
Bumblebee (Bombus magnus)
-
Small Heath Bumblebee (Bombus
jonellus)
-
Garden Bumblebee (Bombus
hortorum)
-
'Shetland' Bumblebee (Bombus
muscorum)
-
Great Yellow Bumblebee (Bombus
distinguendus)
-
-
Colour
illustrations © Tony Hopkins, from `Bumblebees' by
O. E.
Prys Jones & S. A. Corbet. Richmond Publishing Co. Ltd.
Shetland
Biological Records Centre is keen to find out more about Shetland's
bumblebees. Please help us by sending us ALL your sightings of these
insects in Shetland.
Include the species, location (with a grid reference if you can), date and
the habitat the bumblebee was seen in (e.g. moorland, garden, etc.).
Please send
your records to :
SBRC, Shetland Amenity Trust, Garthspool,
Lerwick, Shetland. Tel. (01595) 694688.
Email: sbrc@zetnet.co.uk.
Nature in Shetland
