Except few, almost all crickets are omnivorous but this does not mean that they have the same natural diet. Diet varies even within the same species. Some are absolutely herbivorous as they solely rely on plants matter while others are largely predaceous.
What Do Crickets Eat in the Wild
Crickets would like to eat every kind of organic material if they are not provided with natural food. It is because of this reason that they are declared as ‘Omnivores’. For example, crickets of eastern United States primarily feed on ground dry pet food. That is not to say that all caged crickets consume variety of foods; there are few species which do not abide by this rule. Japanese nemobiine (Parapteronemobius sazanami) is one such exception. It lives on the beaches of Kyushu and Honshu and it rarely eats anything except fresh crab meat.
While many species are omnivores there are some that rely on plants and fruits and are thus called herbivores. Those living on grounds are likely to feed on young plants. Mole crickets are very fond of grasses and other plants that are above and below the ground.
Only a few crickets take on living prey probably due to their small size. Mostly they feed on vulnerable preys such as pupae, scale insects, aphids, molting insects, or even eggs. Oecanthines usually take on aphids but they also feed on fungal spores and plant tissues. Small crickets seldom act as active predators. Anaxipha gracilis predominantly feed on blood-engorged sand flies. Generally, crickets are less likely to take on larger prey.
Plant-dwelling crickets usually feed on a variety of plants but host-specific crickets do not consume the plant on which they live. Oecanthus pini of southeastern United States feel home at pine trees and its color offers an absolute camouflage against potential predators. In captivity they would eat lettuce, ground dog food, and aphids.
Though rarely, crickets also feed on dead crickets if other foods are not available. Generally they consume decaying plant material seeding plants, and fungi.
They have powerful jaws and they can bite humans if provoked.
Mole crickets are omnivores as they heavily rely on worms, larvae, roots, and grasses.
Marmon crickets have a relatively different natural diet in that they feed on forbs too often but they also eat grasses and shrubs like sagebrush.