Worcestershire Record No. 19 November 2005 pp. 22-23
In the November 1999 edition of this Newsletter I mentioned the probability of two species of Orthoptera spreading into Worcestershire – Roesel’s Bushcricket Metrioptera roeselii and Long-winged Conehead Conocephalus discolor. Both of these species have spread dramatically during the last few years and I was sure that it was a case of ‘when’ rather than ‘if’ they were likely to turn up in this county. I also noted two other species, the Bog Bushcricket Metrioptera brachyptera and Stripe-winged Grasshopper Stenobothrus lineatu), both found in adjacent counties but not known from Worcestershire. These latter two species are habitat specific, so I was hoping that populations may have remained over-looked at suitable sites. There follows an update of these four species in relation to Worcestershire.
Bog Bushcricket Metrioptera brachyptera – Nationally restricted to ‘lowland heaths and clearings in moist, heathy woodland’ (Marshall and Haes 1990). The National Atlas (Haes and Harding 1997) shows the closest records for this species as east of Birmingham (I guess Bickenhill Plantation), south-west Staffordshire (most likely to be Highgate Common) and in the Cleobury Mortimer area. It appears to be absent from Worcestershire but further searches of our heathland might just turn up an isolated population.
This is a typical Bushcricket with very long antennae and long hind legs. Usually brown (sometimes green) with a bright green underside. Also only the back edge of the side of the pronotum is pale. Wings are obvious but shorter than the abdomen. Compare with the ‘common’ Dark Bushcricket Pholidoptera griseoaptera which has tiny wings and no obvious pale edge to the pronotum.
Stripe-winged Grasshopper Stenobothrus lineatus – A species of calcareous grassland. Worcestershire Biological Record Centre now has a single record from the Malvern Hills. Further checks in this area and on Bredon Hill may well be rewarded with more colonies.
This is an easily overlooked species with perhaps the quietist song of all the British grasshoppers. This species is most likely to be confused with the Common Green Grasshopper Omocestus viridulu) but the latter never has a red tip to the abdomen whereas the Stripe-winged Grasshopper does. Also look for a white stripe along the wing and a white stigma. Not so easy to see, but a more definite characteristic of Stripe-winged Grasshopper is the area of enlarged ‘cells’ in the central area of the wings.
|Long-winged Conehead Male
Photo: Gary Farmer
Long-winged Conehead Conocephalus discolor – This species was first discovered in Worcestershire in 2003 when a single specimen was collected from road side vegetation in the south of the county (John Meikljohn, Worcestershire Record No 15). Further searches that year and in 2004 failed to find any other individuals. It was therefore a surprise when a small colony was discovered in Redditch in 2005 (the opposite end of the county!). Long-winged Coneheads were only really found in scrub land along the south coast of England in the 1960’s. Over the subsequent years they began to spread northwards, accelerating their expansion during the 1990’s.
A green Bushcricket with a brown stripe down the full length of the back. Their wings are at least as long as the body.
Roesel’s Bushcricket Metrioptera roeselii – Like the previous species, Roesel’s Bushcricket was an insect restricted to the south of the country, found on grazing marshes and estuaries. As it has pushed north and east it has become a little less fussy about its chosen habitat. Un-mown grassland with thistles and rushes in a sheltered location is ideal. This species was found in south Warwickshire in 2004.
In 2005 during a ‘Recorders’ meeting I found a large colony in Arrow Valley Park in Redditch. This colony must have been overlooked for a year or two to have built up such numbers. A week later Roesel’s Bushcrickets were found in the south of the county on Bredon Hill (P. Taylor and J. Hardy). At the same time J. Day found this species in West Gloucestershire, so there must be more to find in Worcestershire.
This is a striking, unmistakable cricket with a pale ‘u’ shape on the side of the pronotum and two or three pale dots on the side of the abdomen.
|Roesel's Bushcricket male
Photo: Gary Farmer
|Roesel's Bushcricket female
Photo: Gary Farmer
One more species is heading our way and will add a quite spectacular invertebrate to the county list when/if it arrives. This is the Great Green Bushcricket Tettigonia viridissima.
With more people becoming interested in identifying Orthoptera I am sure we could put quite few more ‘dots on the map’ during the coming years – watch this space.
With the advances in digital photography it is becoming easier to identify these fascinating insects without the need to capture them. I would gladly accept photos for identification if they are accompanied by a grid reference, site name and date. Send to email@example.com.
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