Insect external structure
Insect internal structure
Development of insects
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Cockroaches / roaches
Green grasshoppers / katydids
Insect identification > Orthoptera > Crickets
Family Gryllidae (the crickets). - The crickets are familiar insects, often seen walking or leaping over the ground. Their wings, though usually present, are sometimes reduced in size.
In some cases they are lacking. When present, the front pair are so bent that one part lies flat over the back while the other lies against the side of the body when not in use.
The antennae are, in most cases, longer than the body. A convenient grouping of these insects is into the field crickets, the mole crickets and the tree crickets.
The sounds are produced by the wings of the males, which are rubbed over each other. On one wing is a strong vein which bears cross ridges, while on the other is a thickened area. These two parts (termed file and scraper by Comstock) when rubbed together cause the sound. Ears in crickets are located, as in the last family, on the forelegs, but the two on the same leg differ somewhat in appearance. The common field crickets are black or brown, and a long ovipositor is present in the females.
They are rather indiscriminate feeders, consuming either vegetable or animal materials, and may even be cannibals. In houses they will eat foods but are rarely abundant enough to become pests. The mole crickets are larger and stouter than the common field crickets and because of their habit of burrowing in the ground are less often seen. They are brown in color and their forelegs are broad and flat, forming most effective digging organs. The eyes are much reduced and the hind legs, not being used for leaping, are not so greatly developed as in the other crickets. They prefer rather moist land in which to make their burrows and feed on plant roots, earthworms and insect larvae.
The "changa" (Scapteriscus vicinus Scudd.) of Porto Rico attacks the roots of various crops in that island, causing much injury, and has recently been discovered along the seacoast of some of the Southern states where it attacks cotton and may become a serious pest.
The tree crickets differ greatly in appearance from the field and mole crickets, being slender, greenish white and only about half to threequarters of an inch in length. They occur on trees and bushes and attract attention from July till frost by their shrill, steadily repeated note or song, beginning as it grows dark and continued through the night, the rapidity of the note being so closely related to the temperature that by timing the number of repetitions per minute a close approximation to the thermometer reading can be obtained. The tree crickets are rather serious pests as during the fall the females make long rows of punctures in the twigs of trees and in berry canes, laying their eggs in these punctures which usually are nearly as deep as the diameter of the twig or cane. The general result is the drying and splitting open of the portion of the plant attacked, causing its death, besides providing an opportunity for the spores of fungous diseases to enter and attack the plant. Control of these insects is at present limited to cutting off and destroying the injured parts of the plant, with their contained eggs, before these hatch in the spring.
A few species of crickets live a semiparasitic life in ants' nests and in consequence are so much modified as to show little resemblance to the common forms.