Unusual abundance of the long-winged form of Roesel's Bush
Cricket Metrioptera roeselii (Hagenbach) form diluta in 2004
Jerry Bowdrey Colchester Museums, 14 Ryegate Road Colchester COl 1YG
I was interested to read Tim Gardiner's Orthoptera report (Gardiner 2004) detailing the
discovery of a macrapterous or long-winged Metrioptera roeseli (Hagenbach) form diluta
in his house at Galleywood (TL7102) on 9* July 2003.
On 15* July 2004 a male, fully-winged bush cricket was brought in as an enquiry to
Colchester Natural History Museum from Braintree (TL72) and proved to be another
diluta. Whilst walking to work on the morning of the 20* July 2004 I noticed a large
bush cricket at rest on a shop wall at the junction of Brook Street and East Hill in East
Colchester (TM0025), another male M.roeseli f. diluta. To my surprise, on reaching the
top of East Hill, I saw another long-winged male, also at rest on a wall. Later in the
month, on 27"' July, whilst carrying out an invertebrate survey on a piece of land adjacent
to Rowhedge Marshes (TM0322), form diluta was abundant amongst a population of
Roesel's in long grass, both males and females being seen. On the same day, in south
west Essex, one flew indoors into the kitchen of Debbie Broom, near Gidea Park Station
(TQ5290) (see Plate 2). The form diluta, were also present at Ferry Marsh, Wivenhoe
(TM0321) on 6"' August and the next day I noticed one in long grass in my garden at
Thorpe-le-Soken (TM1722).
Roesel's Bush Cricket is normally brachypterus (short-winged), Marshall and Haes (1988)
state that the form diluta sometimes occurs in relatively high numbers in very hot
summers, whereas Wake (1997) suggests that it is occasionally encountered (in Essex).
I can certainly not recall seeing more than one or two long-winged individuals in any
one season, but would suggest that the reason for high numbers in 2004 may be a response
to the hot summer of 2003 when roeselii was also observed to have matured earlier than
normal (Gardiner, loc. cit.).
My thanks to Debbie Broom for permission to use her photograph
References
Gardiner, T. (2004) Orthoptera and allied insects of Essex 2003. Essex Naturalist (New
series) 21: 69-74.
Marshall, J.A. & Haes, E.C.M. (1988) Grasshoppers and allied insects of Great Britain
and Ireland. Harley Books.
Wake, A.J. (1997) Grasshoppers and Crickets of Essex. Colchester Natural History
Society
Essex Field Club Newsletter No. 46, January 2005
19