22
within the bee cell.
Here another remarkable adaptation comes into
play. The cell in which the fly has spent its
early life was carefully sealed up by the bee
when it had laid its eggs and stored its
honey supply. The Bee fly now needs to escape,
the maggot was too soft to do the job and the
adult fly on emergence from the pupa will not then
be able to escape from its tomb. So the pupa
does the job. The second pupal stage develops
a coronet of spines with which it breaks out of
the cell to the surface of the soil. The skin
then splits and the fly emerges. Ten months or
so have passed and so the cycle continues.
Bombylius major is on the wing in good years from
late March until early May. Other species can
be found in mid-summer. Many other Bombyliids
have similar life cycles and others attack
Beetles or Moth larvae.
I would be pleased to see any flies Bombyliid or
otherwise, please send them with date and site
of capture to: D.A. Smith
32 Edenhall Road
Harold Hill
Romford
Essex
References: Royal Entomological Society
Handbooks for the Identification of British Insects
Vol. IX pt 4, pp 110 - 121.
Flies of the British Isles. Colyer and Hammond
pp 108 - 111.
Parasitic Insects. R.R. Askew. pp 188 -190.
D A SMITH