Grasshoppers go in many a thumming spring (John Clare)
The subdivision of insects comprising grasshoppers, known as the Orthoptera, which also contains the crickets and a separate group, the katydids or bush crickets, first appeared in the fossil record during the Carboniferous Period, some 350 to 300 million years ago.
Recently, through DNA analysis, grasshoppers have been identified as the last of the three related groups to evolve, breaking away from an ancestral form of Orthopteran during the Cenozoic era, just a mere 50-65 million years ago. It was once thought that the early origins of this group were in the African savanna, but more recent studies have revised this theory, based on the development of the first grasslands in what is now continental South America.
The Orthopterans are so-called because in Greek the first syllable ‘orthos’ means straight or rigid, referring to their modified front wings, specially toughened into a leathery covering to protect the hind wings for those species that use them to fly. Previously, the Orthopterans had been named by the more behaviourally descriptive name Saltatoria which hails from the Latin ‘saltare’ meaning to leap.
The chirping sound heard in daytime is usually only by male grasshoppers. Grasshoppers use specialised ‘pegs’ on their hind legs to rub on a reinforced rib on the forewings. This sound is one of those characteristic features of the English summer. When melodious it might attract a female: at other times it might be more strident, to warn off other males from a territory. The tympanae (hearing organs), which are located on either side of the abdomen, are positioned such that one is slightly further back than the other. This creates a minute time delay between the two hearing organs, thus providing clues to the origin of the sound. Interestingly, owls utilise a similar albeit much more sophisticated acoustic approach to hunt their prey.
Grasshoppers can be distinguished from crickets by their antennae. The latter have long antennae, often extending beyond the length of their bodies whilst grasshoppers’ antennae are short, clearly segmented and stout. Though grasshoppers tend to chirp some of their cricket cousins produce a melodious repertoire of songs. So prized was the singing of crickets that they have probably had a long association with humans, who would capture them and keep for their delightful nocturnal singing. Even today crickets are kept in some African homes for their singing.
Grasshoppers and their relatives are almost exclusively vegetarians with specialised downward-pointing mouth parts for chewing grasses and cereals and in one case, mosses, which is unique in the insect world. In contrast to tropical regions, where the largest grasshoppers or locusts rule supreme and are a serious pest of agricultural produce, in the UK grasshoppers are less of a serious threat to cereal crops than other pests.
Of around 8,000 species of grasshoppers worldwide, they are represented in the UK by just 14 examples, although global warming is now resulting in some sightings of the migratory locust in southern England.
The biggest British species, found only on peat bogs, is appropriately named the ‘large marsh grasshopper’, and is around 1.25 inches long. Probably the most frequently seen or heard of all grasshoppers across all the UK, 0.75 inches in length, is the ‘common field grasshopper’. Its chirping call is one of the loudest grasshopper chirps in the UK and the metallic scraping sound has been likened to that of a dentist’s drill!
Female grasshoppers lay up to 14 eggs in a frothy substance that hardens into a protective envelope or ‘pod’ on the soil, which protects it over the winter. In May the eggs hatch. The nymph is enclosed in a worm-shaped casing to enable it to crawl undamaged through the soil. Grasshopper nymphs take five months to progress through five moult phases or instars, before the adult grasshopper emerges. Overall, a grasshopper can be expected to live for five months.
Because of the cryptic colouration of grasshoppers: shades of green, buff, purple or brown, they are more usually heard rather than seen. This sentiment is most elegantly expressed in a quote from the early half of the 20th century which I came across recorded in a 1972 insect field guide I have: “Grasshoppers and crickets share with radio announcers the distinction of being known more by their voices than by their looks because, although these insects noisily advertise their presence, their colouring normally ensures that they remain hidden from the casual stroller”.
My own experience tends to confirm this. Having heard the chirps in the long grass, often they then go silent as they have obviously detected my presence through ground vibrations, or with their large compound eyes, or their membranous hearing organ located on their abdomens (crickets’ hearing organs are on their front legs). Usually, no amount of patience, scrutinising the nearby tussocks of grass or waiting for the critters to hop to a new leaf of grass is rewarded. Instead, one is forced to take a step or two in the general direction where the sound stemmed from to see if I can encourage the insect to reveal themselves.
Most grasshoppers have wings but their default solution for rapid movement is to use their characteristically elongated rear legs to catapult themselves away from predators, to find a mate, or to find new feeding grounds. These legs, which are designed specifically for springing great distances, relative to their size, have muscles which attach the knee joints containing a coiled spring to the hind feet which store energy for explosive jumping.
Here to conclude is a poem by Northamptonshire poet, John Clare, which beautifully exemplifies these unique travelling habits of grasshoppers:
Grasshoppers go in many a thumming spring
And now to stalks of tasseled sowgrass cling,
That shakes and swees awhile, but still keeps straight;
While arching oxeye doubles with his weight.
Next on the cat-tail-grass with farther bound
He springs, that bends until they touch the ground.
Chris Brown BEM
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