previous U.K. range, and now seems to be
extinct in Essex. Another, Bombus ruderatus.
has been recorded only very rarely and may
well also be extinct in the county. However,
several species, most notably 'cuckoo' bees of
the genus Psithyrus, seem now to be more
widely distributed. It may, of course, be that
this is a misleading consequence of possible
under-recording of this group in the earlier
surveys. It has proved remarkably difficult to
obtain detailed information about the original
data used to compile the ITE maps.
Field-observation and Recording
There is an understandable reluctance on the
part of many recorders to kill Bumblebees in
order to be sure of correct identification.
Unfortunately, although colour patterns and
other field characters can be good guides to
identification, they are not infallible. Some
species are quite variable in their colour
patterns, and colours also fade with age in
ways that can be quite confusing. Having said
this, however, I have found that a couple of
season's study makes it possible to identify
almost all species in the field with reasonable
confidence. Where colour-pattern alone is not
decisive, a bee can be caught (either with a
net, or, often more easily, by placing a tube
over a busily foraging bee while it is on a
flower). Once placed in a glass tube, the bee
can be quietened down by pressing into the
tube a wad of cotton wool or tissue. This can
be used to press (the bee gently against the
glass, so preventing its movement and
allowing inspection with a x10 lens. This is
usually enough to check relevant diagnostic
features, and the bee can be released
unharmed. The process is surprisingly so
inconseqential to the bees that they will often
continue foraging immediately if returned to
the flower from which they were taken!
In addition to recording the distribution of the
Essex species, the current survey has included
detailed recording of the forage sources used
by each caste of all the species at different
times of the year. Note has also been made of
the flight-periods of each caste of all the
species, and this gives some clues as to the
time taken to complete the life-cycle, and to
the occurrence of double-broods in some
species. More detailed studies are now being
made of the ecology and life-histories of
species which arc declining most rapidly in the
U.K. generally, or specifically ill Essex. There
is insufficient space to present much of this
new information here, but it will be presented
more fully in a forthcoming book on the
Bumblebees of Essex.
The Essex Species
There are six species of the genus Bombus which remain common and widespread in Essex.
They are:
Bombus lucorum (Linnaeus).
The queens are black, with one lemon-yellow band across the front of the thorax, and another
across the front of the abdomen. The last segments of the abdomen have white hairs. Workers
are similar, but smaller. Over-wintered queens can be found foraging as early as February, and
there is some evidence of year-round activity for this species in climatically favourable parts of
the county. However, my earliest record for workers of this species is the second week in April.
Fresh males and females appear from the last week in May onwards, and workers continue to be
seen foraging into September in some years. The males are quite distinctive in appearance,
having more extensive areas of yellow hairs. There are usually two bands of yellow on the
thorax, and the yellow band on the abdomen is wider than in the females - sometimes extending
almost to the white 'tail'. There is also a tuft of yellow hairs on the front of the head. This
species is common and widespread throughout Essex. It is able to exploit a wide variety of wild
and cultivated flowers as forage-sources, and is commonly found in urban parks and gardens.
Essex Naturalist (New Series) 16 (1999)