Wikijunior:Bugs/Cricket

What does it look like?
Crickets are small, often nocturnal insects. They are usually dark brown or black, so that they blend in with the ground. They have six legs. Four are walking legs and two large back legs are used to make very long jumps. Attached to the head are two long antennae, also known as feelers, used for touching and smelling. Crickets are sometimes confused with grasshoppers because they are similar in size and body shape, but grasshoppers have shorter antennae and are green in color.

Crickets are related to grasshoppers. True crickets belong to the Family Gryllidae. They have a broad, somewhat flattened body between 3/8 inch and 1 inch in length. The long, tapered antennae (feelers) usually grow much longer than the body. Most crickets have flat overlapping wings on top of the back. Some species have tiny wings and others are wingless. Females have long, needlelike ovipositors for laying eggs.

Both males and females have a flat, round tympanum (hearing organ) in each front leg. Males have a hard, sharp-edged “scraper” on the right forewing. The scraper is rubbed with a thick, toothed vein on the left forewing. The action of the vein on the scraper (stridulation) produces sound.

Field crickets (Gryllus assimilis) are also known as common black crickets. They are brown, red or black in color and about 1/2 to 1 inch long.

House crickets (Acheta domesticus) are light yellowish-brown in color. They have a light-colored head with three dark bands on top and between the eyes. The wings cover the abdomen. There is another pair of long hind wings at the very tip of the abdomen. These are sometimes shed in adulthood. There are spines on the hind legs.

Tree crickets belong to the genus Oeceanthus. They are usually green with broad transparent wings. Snowy tree crickets are about 1/2 inch long and pale green to white in color. They have a very slender body and two long antennae.

Ant-loving crickets (Myrmecophila) are a tiny wingless species, less than 1/4 inch long and about l/4 inch wide.

Bush crickets are slender and range from 1/4 inch to 3/4 inch in length. They are brown or gray in color. They may have small wings or no wings at all. Some female bush crickets are called “sword-bearing” because they have a long, sharp ovipositor (egg laying organ).

Mole crickets are brownish with broad, spade-like front legs designed for digging. They are usually about 1 inch long and have relatively short antennae. Pigmy mole crickets are less than 1 inch long.

Only male crickets chirp. They do not rub their legs together to do this. Instead they run the top of one wing against the “teeth” on the bottom of the other wing to make a chirping sound. The wings are held up and open to make the sound louder. In slow motion, they appear to be shrugging their shoulders when chirping. At actual speed, the chirping movements are too fast for the eye to follow.

Crickets have been chirping and singing for more than 300 million years—long before the earliest sounds of amphibians and birds. Experts recognize four types of cricket songs: calling, courting, aggressive, and mating. The calling song is fairly loud. It is meant to attract females and repel other males. The very quiet courting song is used when a female is near. Only signals from a male of her kind will cause a female to approach and accept him as a mate. An aggressive song is used when another male is detected.

Crickets that live in trees and bushes usually sing only at night. Those that live in weeds generally sing both day and night. House crickets and field crickets make songs both day and night.

Females of chirping and singing species have organs on their legs to hear sound. Most camel crickets do not produce sounds, so neither males nor females have hearing organs.

Where does it live?
Crickets have a variety of habitats. They can be found in trees and on or around different types of plant life.

Field crickets are common in North America. They live in fields, lawns, pastures, along roadsides, and in woods. Bush crickets live in tropical areas, such as the south eastern coastal plain of the United States. They are usually found in bushes, under debris near ponds, or moist, sandy areas near water. Tree crickets occur in trees, shrubs, high grass or weeds.

Mole crickets burrow in moist ground and are rarely seen. Pigmy mole crickets prefer moist sandy places along shores of ponds and streams. They burrow in the ground but are sometimes found on the surface. Ant-loving crickets live in ants’ nests.

What does it eat?
Crickets are omnivores and scavengers. They feed on leaves, flowers, bark, and seeds. Some species are predatory, feeding on other insects, snails or even small vertebrates such as snakes and lizards.

Field crickets eat a variety of fruits, vegetables, and ornamental plants. They eat live or dead insects, grasshopper eggs, and pupae of flies, moths and butterflies. Sometimes they steal prey from spider webs. Spotted camel crickets come out on warm humid nights to feed. They eat fungi, roots, fruit, and dead insects, including other crickets. Bush crickets eat leaves, flowers, and fruits of living plants. Ant-loving crickets eat ants’ young.

Tree crickets feed on aphids. Snowy tree crickets eat small insects. They also feed on fruit crops such as apples and peaches.

If keeping a cricket as a pet, they will eat fish food. Crickets will also eat potatoes.

How does it defend itself?
The main predators of the cricket are frogs, lizards, tortoises, salamanders, and spiders.

Unlike other insects, crickets do not actively defend themselves. Crickets have cerci (long hairs) at the end of the abdomen to detect movement. They use their strong legs to hop away from danger. Some use camouflage to blend with their surroundings.

Crickets cease sound production when they detect a disturbance. If captured, they will try to wrench free, risking the loss of a leg, without making a sound.

Bush crickets have a row of spines on the hind legs to deter predators. Some bush crickets are unable to make sounds. Since they are relatively large, sound might increase the danger of being detected. Their silence may protect them from predators.



What stages of metamorphosis does it go through?
Crickets undergo simple or incomplete metamorphosis. They develop in three main growth stages—egg, nymph, and adult. There is no “resting” stage before the adult stage. They mature in 6 to 8 weeks after molting 6 to 12 times. One generation hatches each year. Crickets cannot make sounds until after the final molt.

Bush crickets lay eggs in pith, bark, or soft wood of plant stems. Female house crickets deposit eggs in damp sand, peat moss, and other moist places. They complete their life cycle in 2 to 3 months in warm weather.

Field crickets lay eggs in warm, damp soil. Newly hatched nymphs burrow up to the surface where they molt 8 to 10 times. In 2 to 3 months they become adults.

Female snowy tree crickets make a series of tiny holes in the bark of the host plant to lay eggs. The egg stage lasts through cold winter months. Eggs deposited in early autumn hatch as nymphs in spring. One generation is produced each year.

What special behavior does it exhibit?
The very regular chirping rate of snowy tree crickets is a common night sound in many places. As the temperature drops, songs become slower and the pitch of the song falls. People use the chirp rate to estimate the temperature.

How does this bug affect people?
Crickets are attracted to light so sometimes they come indoors. When inside a house they like to eat clothes made from cotton, silk or wool. Crickets are sometimes eaten by people! This is common in Africa or Asia, where they are considered a delicacy. In other places it is considered good fortune to have a cricket in the home because the singing is pleasant. Crickets are popular pets and are considered good luck in Asia.

Crickets are harmless to humans. They are used to catch many kinds of fish. They are sold as food for reptiles, lizards, and frogs. In ancient China, crickets were valued pets kept in golden cages.

Field crickets are considered a nuisance pest because of their chirping. They sometimes cause damage to fruit and vegetable crops. They are known to chew on wood, rubber, plastic, or leather. Snowy tree crickets may cause damage to fruit crops by introducing disease.