Thursday, July 20, 2017

Soundtrack to Summer


Today's Guardian Country Diary is about grasshoppers.

These lovely insects, that provide a soperific soundtrack to late summer, are sun-loving so their greatest species diversity in the UK is concentrated in southern England.

We have two common species here in the North Pennines ......















... the green grasshopper  Omocestus viridulus....






















.... and the meadow grasshopper Chorthippus parallelus.

Both 'sing' by stridulating - dragging those pegs on their hind femur over the hard edges of the wing. The meadow grasshopper has the most varied song and both sexes chirrup, though the female's song is quieter than the male's because those stridulatory pegs tend to be smaller in females.

Males have three distinct songs - a loud one for attraction, a quieter one for courtship and a stucatto one during mating. 















They can be hard to spot because they are well camouflaged amongst dry grasses and heather, and on warm afternoons their -leap-flutter-glide escape technique can make them hard to catch.














Grasshoppers hatch from overwintering eggs as a tiny worm-like organism that then undergoes four moults as the nymph grows. This is a meadow grasshopper in the  penultimate instar before becoming an adult - it still has wing stubs but these will reach full size during the next moult. 
















This female, sitting in the sun amongst bell heather, has lost her hind leg on the left-hand side. Nymphs in early instars can regenerate lost legs but this one must have lost the limb after becoming an adult, perhaps to escape the grip of a bird's beak.

Surprisingly, there are documented instances of grasshoppers that have lost a hind leg being able to stridulate and respond to a mate's song with the remaining limb. The impediment must make for lop-sided leaps though!


2 comments:

  1. So much so from such a small thing. I've probably posted this link before, but reading the post brought back very happy memories. https://uphilldowndale.wordpress.com/2009/08/11/something-special/

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    1. That's lovely! I've got David Measures' butterfly book

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