Roesel’s Bush Cricket

Alan found a rare form of the above Cricket at Cholsey Marsh yesterday.

Wikipedia has this to say regarding the Long-winged form:

“Both male and female adults are normally brachypterous. However, a macropterous form, f. diluta (described by Charpentier 1825) also exists. These have much longer wings, and usually make up less than 1% of the total population, but in some populations occur in much higher numbers, usually in areas where the bush-cricket's range has recently expanded to.

They are more common in long, warm summers where populations reach higher densities. It has also been suggested that a very localised hostile environment may also produce a higher level of macropterous forms. The macropterous form is a dispersal phase, and it provides the advantage of reaching new, more favourable habitats, within which there is a lower density of Roesel's bush-crickets residing. Well established populations tend to be more highly brachypterous, as high dispersal ability is correlated with lower fecundity in Orthoptera.”