Gryllidae

These crickets appear somewhatflatdorsally because a portion of the front wing is held horizontal over the body, instead of being held vertically, as in grasshoppers. The female ovipositor is usually needle-like, and the cerci are long. Eggs are laid singly or in small batches in soil, or in crevices. Nymphs and adults feed primarily on vegetation. Males stridulate by rubbing together modified regions of the front wings. Crickets do nothave a fixed song length. They will sing indefinitely as long as their surroundings are relatively warm; the chirps slow in cool temperatures. Several species regularly occur indoors or around the perimeter of buildings in rural and urban areas. The Indian house cricket, Grylloides supplicans, is a common indoor pest in Central America. The very large African cricket, Macro-gryllus consocius, burrows in sandy areas along coastal southern Africa. These are social crickets; they have loud songs and can be heard from a long distance.

Black field cricket, Teleogryllus commodus Adults are about 34 mm long and black. Eggs are laid in the summer under objects on the ground or in crevices in the soil; hatching occurs the following spring (October). Large populations of this field cricket can develop; in the fall they move into urban environments and enter houses. This species occurs in New Zealand and Australia.

House cricket, Acheta domesticus (Fig. 13.1a) Adults are 16-26 mm long. The body is yellowish to mottled brown and pale brown; there are three dark cross-bands on the head. The ovipositor is long and the cerci are long in both sexes. Wings are well developed and these crickets readily fly. Eggs are 2.5 mm long, whitish yellow, and banana-shaped. They are deposited singly or in small batches in moist cracks and crevices; fecundity is 40-179 eggs, but 728 eggs were reported at 28 °C. Hatching occurs in 1-12 weeks, depending on temperature. Development in the laboratory is about 56 days for males and 53 days for females; under variable or field conditions development takes about 35 days at 32 °C and 60 days at 27 °C, with 9-11 nymph stages. Adults live about 90 days at 27 °C. Adults and nymphs feed on plant material outside, and on household foods inside, especially liquids. They overwinter in the egg stage and there is one generation per year. This species is native to northern Africa and Middle East, but it is distributed in eastern North America, Europe, and India. It has been introduced into Latin America.

This cricket occurs indoors and outdoors throughout its range, and it is established in buildings in Europe. References to the cricket of the hearth are common in English literature and refer to this species. They occur indoors in heated locations, and outdoors where temperatures are slightly above the surroundings. Adults are attracted to lights at night; they can climb rough-surfaced buildings. They can occur in large numbers in refuse dumps and urban landfills. These sites are usually kept warm throughout the year by fermentation of wet organic material. From landfills crickets canmove to surrounding buildings. Large numbers of adults have been reported moving from breeding sites such as refuse dumps to nearby buildings. The normal song is short shrill bursts repeated regularly for long periods. They typically chirp at dusk and during the night, but they can be heard during the day in landfills during warm weather.

Field crickets, Gryllus assimilis, G.pennsylvanicus, G. campestris (fig. 13.1e) Adults are 13-28 mm long. The body ranges in color from black to yellowish brown. Front wings are shorter than the hind wings, and the frontwings can have orange markings. Females have a long, slender ovipositor, and long cerci. Eggs are 2.8-3.2 mm, brownish yellow, and they are deposited singly in damp soil; 50 or more are placed within a small area; fecundity is 150-400 eggs. Developmentfrom egg to adulttakes 78-93 days; there are 8-9 nymph stages. Adults live for about 2 months, and in the fall they are usually killed by frost. Adults

Figure 13.1 Orthoptera. (a) Achaeta domesticus female (Gryllidae); (b) Neocurtilla hexadactyla female (Gryllotalpidae); (c) Gryllotalpa gryllotalpa, left front leg; (d) Ceuthophilus maculatus female (Raphidophoridae); (e) Gryllus pennsylvanicus (Gryllidae).

and nymphs feed on plant material, but indoors they often damage plant and animal fabric, such as cotton, wool, silk, and fur. In north temperate regions there is usually one generation per year and they overwinter in the egg stage. In warm climates, there are two or more generations per year and they overwinter as eggs or large nymphs. These species have a wide distribution and they are found in North America and Europe. The several species of Gryllus are similar morphologically, but are separated based on habits, life history, and song.

Large numbers are known to occur around buildings in primarily rural areas. They are most abundant in the fall when adults gather at structures, perhaps attracted to lights or the sunlightheatretained by structures during the day, and radiated at night. Populations may persist in an area for several years, especially during drought conditions. In some desert valleys of southeastern California, large numbers offield crickets move to inhabited areas following summer thunderstorms.

Gryllus bimaculatus Adults are about 28 mm long; the body and legs are shiny black. The thorax and base of the frontwings have pale white markings. This species is widespread and common in Asia, Mediterranean Europe, and all of Africa. It occurs in peridomestic habitats, and occasionally enters houses and other buildings. A closely related species, G. domesticus, the black-headed cricket, occurs in Indiaand is oftenapestindoors when vegetation outdoors is scarce.

Winter cricket, Gryllodes sigillatus This cricket is legendary in Japan. Although of tropic origin, it was common in public baths and in households, primarily kitchens, in northern Japan. Itfeeds on greasy and fatty foods and is injurious to paper, cloth, and leather bookbinding. The modernization ofhousehold and introduction of gas cooking stoves and water heaters removed the niche occupied by this cricket. Limited populations existin northern Japan.

Temperature cricket, snowy tree cricket, Oecanthus fultoni

Adults are 12-15 mm long. The body is pale green with a yellow head and pale yellow antennal bases. This species is found on shrubs and small trees, where it feeds on aphids. It is called the temperature cricket because the air temperature can be estimated by counting the number of chirps per minute, dividing this number by four, and adding 40 to obtain the degrees Fahrenheit, or dividing it by six to obtain the degrees Celsius. This species occurs nearly throughout the USA.

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