Worcestershire Record No. 24 April 2008 p. 21

A MASON WASP NEW TO WORCESTERSHIRE SYMMORPHUS CONNEXUS (CURTIS, 1826) (VESPIDAE: EUMENINAE)

Kevin McGee

Symmorphus cannexus (male) © Kevin McGe
I netted this small ‘Mason Wasp’ while it was in-flight amongst low trackside vegetation in the middle of Tiddesley Wood on 4th July.2007. I keyed it out as Symmorphus connexus (male) but upon discovering the scarcity of this species I sought a second opinion from Geoff Trevis. He agreed with my determination but decided to send the specimen to Mike Edwards who has now confirmed that it is S. connexus.

The national status of this species is listed as very rare by M.E.Archer. There are recent records from Kent, Hampshire and Oxfordshire. Symmorphus species nest in existing cavities in a variety of situations ranging from dead plant stems to old walls. Prey items are placed in the modified cavity alongside which an egg is laid and the resulting larva then feeds on the prey and pupates in the nest chamber. The prey collected by S.connexus are the larvae of the micro moth Gracillaria stigmatella (Fabr.) and the chrysomelid beetle Zeugophora subspinosa (Fabr.). Both of the latter feed on Aspen foliage. Z.subspinosa is actually rather a localised leaf-beetle, I have just one record of an adult collected from Tiddesley on 12th June 2006 which was determined by P.F.Whitehead. Woods in the county with records of the hosts may contain as yet unknown populations of this rare wasp.

References:
EDWARDS, R. 2000. Provisional Atlas of the aculeate Hymenoptera of Britain and Ireland. Part 1. BWARS

Acknowledgements:
With thanks to Geoff Trevis and Paul Whitehead for their expertise.

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