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Field crickets are insects of order Orthoptera. These crickets are in subfamily Gryllinae of family Gryllidae. They hatch in spring, and the young crickets (called nymphs) eat and grow rapidly. They shed their skin (molt) eight or more times before they become adults. Field crickets eat a broad range of feeds: seeds, plants, or insects (dead or alive). They are known to feed on grasshopper eggs, pupae of Lepidoptera (moths and butterflies) and Diptera (flies). Occasionally they may rob spiders of their prey. Field crickets also eat grass. "Field cricket" is a common name for ''Gryllus assimilis'', ''G. bimaculatus'', ''G. campestris'', ''G. firmus'', ''G. pennsylvanicus'', ''G. rubens'', and ''G. texensis'', along with other members of various genera including ''Acheta'', ''Gryllodes'', ''Gryllus'', and ''Teleogryllus''. ''Acheta domesticus'', the House cricket, and ''Gryllus bimaculatus'' are raised in captivity for use as live food for exotic pets. ==Identification== Field crickets are normally in size, depending on the species, and can be black, red or brown in color. While both males and females have very similar basic body plans, each has its own distinguishing feature(s). Females can be identified by the presence of an ovipositor, a spike-like appendage, about long, on the hind end of the abdomen between two cerci. This ovipositor allows the female to bury her fertilized eggs into the ground for protection and development. In some female field crickets, species can be distinguished by comparing the length of the ovipositor to the length of the body (i.e. ''G. rubens'' has a longer ovipositor than ''G.texensis''〔Gray, D.A.,Walker, T.J.,Conley, B.E., Cade, W.H. 2001. "A Morphological Means of Distinguishing Females of the Cryptic Field Cricket Species, ''Gryllus Rubens'' and ''G. Texensis'' (Orthoptera: Gryllidae)". ''Florida Entomologist'', 84:314-315〕). Males are distinguished from females by the absence of an ovipositor. At the end of the abdomen there are simply two cerci. Unlike females, however, males are able to produce sounds or ''chirps''. Thus, males can be identified through sound while females cannot. Diagram A shows the male cricket with its wings raised for the purpose of chirping. Diagram B shows the female cricket, identified via the long protruding ovipositor at the end of the abdomen. D and E show the female using the ovipositor to deposit the fertilized eggs into the ground. Diagram C shows a topical and side view of nymphs with no protrusion at the hind of the abdomen. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Field cricket」の詳細全文を読む スポンサード リンク
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