Devon's Grasshoppers and Crickets
PUBLISHED: 16:36 01 September 2008 | UPDATED: 15:25 20 February 2013
David Chapman investigates the intriguing world of Devon's grasshoppers and crickets
If we have an Indian summer with warm days stretching well into September, we can look forward to evenings in which we are serenaded by some of nature's noisiest yet smallest critters - grasshoppers and crickets. The sound created by each of these small insects might be fairly insignificant, but their collective 'voice' is quite impressive, and the manner in which they make their song is even more incredible.
Grasshoppers and crickets belong to the order of insects known as Orthoptera. Around the world there are over 17,000 different species of Orthoptera, of which just 30 occur in Britain and about 22 of these are found in Devon - and they have all developed a slightly different song. Recognising the species from its song is no mean feat but obviously the grasshoppers have mastered it! The 30 British species in this order are split into the two families known as grasshoppers and crickets. These two families can be distinguished from each other by the way in which they make their song, the time of day during which they are active, some of their physical features and their diet.
One of their most unusual features is their song, but how and why do they make such a loud noise? Well, the why bit is simple to explain. If you were small and green and lived amongst the grass, imagine the trouble you would have in finding a mate! The first singing grasshopper must have been a real hit: no problem in attracting a partner, settling down and having baby grasshoppers through which its singing genes could have been passed.
How grasshoppers and crickets 'sing' is very clever and I use the word loosely because it isn't singing as we know it, as it isn't created from the mouth parts of the insect at all. All grasshoppers and crickets create the familiar sound by rubbing two parts of their body together, a process known as stridulation, and though different species rub different body parts, the effect is very nearly the same. One of the two surfaces has a row of 'teeth', known as stridulatory pegs, the other surface is stiff and the effect of rubbing them together is similar to that of running a finger nail along a comb.
Grasshoppers tend to be more active during sunny spells and rub the long hind legs against their forewing to sing. Most crickets on the other hand are crepuscular, so they sing at dawn and dusk, and unlike the grasshoppers, they rub their wings together to create their song, a sound which tends to be higher pitched than that of the grasshoppers.
The two families differ in their choice of diet. Grasshoppers are exclusively vegetarian whereas crickets are omnivores, eating other insects as well as vegetative matter. Another feature which helps to distinguish between the two types of insect is the length of the antennae; those of crickets tend to be much longer than those of grasshoppers. Female crickets have one more feature which sets them apart from the other Orthoptera and that is an obvious blade-shaped ovipositor at the rear with which they push their eggs into vegetation or sometimes into the ground.
Late summer is the best time to see these creatures, particularly if it is warm and dry. Look for grasshoppers as they jump just ahead of your feet as you walk through rough ground or meadows. Crickets can be found climbing on brambles and other scrub as well as basking on walls and rocks. If you can find them when it is a little colder, early in the morning for example, you should be able to have a closer look at them. There are a variety of shapes and colours; in fact there is a great deal of variability even within species, ranging from pink to brown to green. Some species, particularly grasshoppers, have large hind legs for jumping and often have well-developed wings to help them 'jump' further; others, particularly the large crickets, are plodders with slightly less panache.
There is something rather special about lying in a meadow on a warm late summer's evening and being serenaded by Orthoptera. Need I remind you of the sound track behind the line 'goodnight John-boy' of Waltons' fame?
Further reading: A good all-round book for identifying grasshoppers and crickets as well as other British insects is Insects of Britain and Western Europe by Michael Chinery, published by Collins,