Species: Common Field Grasshopper (Chorthippus brunneus)
Family: Grasshoppers and Locusts (ACRIDIDAE)
Category: Insects (Other)
Location: Widespread
A. Insects (Other)
More extensive information on insects can be found in a separate blog post.
B. Grasshoppers and Locusts (ACRIDIDAE)
Although Bush-crickets and Grasshoppers are related, there are distinct differences between the two families. Crickets stridulate by rubbing their wings together at dusk, their 'ears' being on their front legs. (In contrast, Grasshoppers stridulate by rubbing their hind legs against their wings, their 'ears' being at the base of their abdomen.) Whereas Grasshoppers are mostly herbivores, Crickets are omnivores. Bush-crickets have long, thin antennae (in contrast to the shorter, stockier ones that Grasshoppers have).
The members of the Grasshopper and Locust family have short, stout antennae and the sound producing tympana membranes on the side of the first abdominal segment. The back legs have three segments. They have ridges along the top edge of the thorax, called keels, which are useful for identification. Grasshoppers have a three stage life-cycle, egg, nymph (going through five moulting instar phases, during which the wings gradually develop), and adult, when final wing development occurs. The most notorious members of this family are the locusts, although these are only rarely found in Britain.
We have a photograph-filled blog post about all the grasshoppers and bush-crickets that we have seen in the Cemetery that may be worth your time.
C. Common Field Grasshopper (Chorthippus brunneus)
This species is extremely variable, and may be brown, green, purple or white. Adults are present in grassy gardens and other green spaces from June until late Autumn.
Images
Common Field Grasshopper
Adult Common Field Grasshoppers are present in grassy gardens and other green spaces from June until late Autumn. Common Field Grasshoppers can be extremely variable in colour, and may be brown, green, purple or white.
Common Field Grasshopper
This Common Field Grasshopper is a mature adult, discernible from its hairy thorax and abdomen and by the indent in its pronotum (the shield plate behind the head). Colours of this species are notoriously variable, and this individual is a good example of those with an orange-red abdominal tip.
There's a nice video on YouTube of a Common Field Grasshopper calling (or 'stridulating') by rubbing its legs against its wings. The resulting 'song' consists of hard "SST" sounds of about 0.2 seconds in duration, produced at intervals of about 2 seconds. When a male Common Field Grasshopper hears this, he knows it's another male of the same species singing, so he joins in. There is then a regular alternating song between the two males, where each male sings in the gaps within the song of the other male. The purpose, of course, is to attract female grasshoppers, and it's likely that the two males are competing for nearby females.
Common Field Grasshopper
The Common Field Grasshopper has a wide range of colours not just the brown of this individual.
We were reasonably sure that this individual was a Common Field Grasshopper, even though the photograph lacks clarity. The waist-shaped pronotum (the 'plate' behind the head) was the main diagnostic feature. However, we were puzzled by this individual's short wings so asked the advice of our county recorder for orthoptera who generously responded with some additional details. What we see in this photograph are the pre-adult wing buds that will expand at the final moult (in the same way that happens with butterflies and moths). In the nymph (the stage before the adult stage), the wings are reversed, so we are seeing the more triangular-shaped hind wingbuds in this photograph. These will be used for flight in the adult, when the hindwings are folded up and hidden below the forewings when the individual is not flying. The upper wing buds are normally just visible at their base, although not in this photograph. When the moult occurs, the adult wings expand rapidly, and once dry are folded down to the side which effectively reverses them.
