Chelostoma campanularum Kirby, Hymenoptera

CHELOSTOMA

CAMPANULARUM HYMENOPTERA E.

KIRBY.

MILNE-REDHEAD

Our house in Nayland, until 30 years ago a farmhouse, still has several old out-buildings and sheds of brick construction with much exposed oak woodwork, which in places is considerably riddled with the exit holes of the woodworm Anobium striatum. Last year I noticed what looked like small black flies Aying near woodworm holes on two different buildings. On closer examination I realised that they were bees. They were trom time to time alighting on the wood and entering the holes. A specimen sent to the British Museum (Natural History) for naming was determined as a qChelostoma campanularum Kirby by M. C. Day, who said it is locally common.

To discover more about its distribution I wrote to M. E. Archer of York, who says that in Britain it inhabits southern England and East Anglia. It is found in Gloucestershire, Warwickshire and Oxfordshire, but not in Staffordshire, Derbyshire or Leicestershire, nor in the South-west. He referred me to Morley (1899), who gives Suffolk records as follows: v.c. 25, Barham; v.c. 26, Brandon district, Rushbrooke and Tostock, varying from not very common to locally plentiful. Only one additional record occurs in Morley (1936), namely Copdock in v.c. 25, but the species had become 'quite rare".

My friend and keen Student of Hymenoptera—Aculeata, V. H. Chambers, teils me he has often found Chelostoma campanularum in Bedfordshire, in nine different localities from 1935 onwards. In 1936 he saw both sexes at burrows in a rotten elm trunk, but he has most frequently seen this bee in flowers of both wild and garden Campanula spp., namely C. rotundifolia, C. glomerata, C. latifolia, C. carpatica and C. portenschlagiana as well as the related genus Jasione. He teils me he once saw a male Aying around flowers of Ballota nigra, whilst it has been observed to visit Taraxacum. Here in Nayland my son-in-law, B. H. Harley, and I observed these bees collecting pollen from nearby flowers of Verbascum phlomoides and Hieraceum amplexicaule and taking it into the woodworm holes. A pair was noticed copulating on a Hieraceum liower-head. It seems that the epithet 'campanu-

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Suffolk

Natural History,

Vol. 17, Part 4

larum was well chosen, but that this species of Chelostoma will also make use of other unrelated flowers.

T h e bees normally entered the holes head first, and came out backwards. W e also noticed one bee go into its hole backwards, presumably a female entering to lay an egg. The holes when completed appear to be lined with clay or fine sand, and a plug of similar material closes the entrance.

T h e bees, which are distinctly gregarious, appear in dancing liight in front of their chosen colony of woodworm holes. They seem to enjoy sunlight, for the aspect of both sites is due s o u t h , so at times the wood gets quite hot. I noticed them on sunny days at the end of June and during the first half of Julv.

S a u n d e r s (1896), with reference to the genus Chelostoma, states that 'the females burrow in old posts or rails', but he adds that Smith says they often employ ready-formed burrows. I cannot accept Saunders' Statement, for clearly this little bee has no adaptations to enable it to burrow in old hardwoods. T h e only other British species, Chelostoma florisomne, is said to breed in straws or reeds. It is illustrated in C h e n e r y (1973).

1 w o n d e r if any m e m b e r s of the Society have come across this interesting little bee, and whether its known distribution in Suffolk can be extended. I am most grateful to the three entomologists who have given me information so enabling nie to write this note.

References C h e n e r y , M. (1973). A Fielet Guide to the Insects of Britain and Northern Europe. 280, 43/8.

Morley, C. (1899). The Hymenoptera of Suffolk, Part 1, Aculeata, 17.

Morley, C. (1936). The Hymenoptera of Suffolk in Trans.

Suf. Nat. Soc., 3, 136.

S a u n d e r s , G . (1896). The Hymenoptera - Aculeata of the British Isles, 300.

E. Milne-Redhead, M.A., F.L S. 43 Bear Street, Nayland. 3! 12/77.