Felicity Jackson gave a fascinating presentation at the Open Meeting on Thursday, October 10, 2013:
Early in September I was walking (slowly) around the north end of the Reserve, looking out for butterflies, bees and, hopefully, hoverflies. Something small moved through the long grass just ahead of me, which for a moment I thought was a minute frog.
No, not a frog - a grasshopper. No, not a grasshopper either, it had a long, blade-like ovipositor (an egg-laying structure, in this case used for cutting into grass stems. Which grasshoppers don't have). And very long, threadlike antennae. It was a bush cricket. A few days later I came back with a camera, and quickly managed to find several more specimens. - and took some pretty bad photos. They were good enough, though, to identify the insects as Long-winged Coneheads.
This creature, with the wonderful name, grass green with brown wings and pretty well camouflaged, used to be found only on the south coast of England. From the 1980s it has moved steadily northwards, reaching Derbyshire about six years ago. Now it's still spreading, and not uncommon in Derbyshire, though it was unfamiliar to me till then.
Conehead, female 2 crpd
So, searching for more coneheads, I returned later in the month, but found none. I had a camera ready, however, and photographed a few brown grasshoppers, one of them quite big. Examining my photos on computer I realised - no, the big one again was not a grasshopper, but another bush cricket. This time more readily identifiable as Roesel's bush cricket. I returned to the reserve again next day, and again found several more. Sitting posed on leaves to have their photos taken.
Roesel's has a similar story : originally a southern coastal and estuarine species, it has spread across the country, especially since the 1980s, reaching Derbyshire around six years ago. It's a successful coloniser: in the south-east of England it's now the commonest bush cricket around..
Both species feed mostly on grasses, and occasional small insects. Body length is up to 18mm - plus, for Roesel's, about 7mm of ovipositor; considerably more in the case of the conehead.
Darley & Nutwood is evidently a haven for bush crickets among its other claims to fame. They may be quite abundant; I only searched a small area (at the north end of the reserve) and found several. And there are indeed abundant grasshoppers; meadow grasshopper (a common species) and almost certain Lesser Marsh. There could be more.
What to find next? I'll be looking out for oak and speckled bush crickets next summer, and possibly the rare dark bush cricket, too. Who knows?
Click on images to view larger version
Long-winged conehead (Conocephalus discolor)
September 4 1 F
September 12 5 or 6, F and couple of M
September 28 1 M
October 6 1F
Roesel's bush cricket (Metrioptera roeseli)
September 24 1 F
September 25 2 (or more) F, 1 M
October 6 1F
Please also visit:
Roesel's Bush Cricket
August Johann Roesel von Rosenhof