Gryllinae

Gryllinae, or field crickets, are a subfamily of insects in the order Orthoptera and the 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 food: 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. In the British Isles "field cricket" refers specifically to Gryllus campestris, but the common name may also be used for G. assimilis, G. bimaculatus, 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 pets.

from Wikipedia