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Keeping crickets as pets as seen at emerged in China in early antiquity. Initially, crickets were kept for their "songs" (stridulation). In the early 12th century the Chinese people began holding cricket fights.〔Yutaka Suga, p. 79, discusses another theory dating cricket fights to the 8th century. However, the earliest ''reliable'' evidence is dated 12th century.〕 Throughout the Imperial era the Chinese also kept pet cicadas and grasshoppers, but crickets were the favorites in the Forbidden City and with the commoners alike. The art of selecting and breeding the finest fighting crickets was perfected during the Qing dynasty and remained a monopoly of the imperial court until the beginning of the 19th century. The Imperial patronage promoted the art of making elaborate cricket containers and individual cricket homes. Traditional Chinese cricket homes come in three distinct shapes: wooden cages, ceramic jars, and gourds. Cages are used primarily for trapping and transportation. Gourds and ceramic jars are used as permanent cricket homes in winter and summer, respectively. They are treated with special mortar to enhance the apparent loudness and tone of a cricket's song. The imperial gardeners grew custom-shaped molded gourds tailored to each species of cricket. Their trade secrets were lost during the Chinese Civil War and the Cultural Revolution, but crickets remain a favorite pet of the Chinese to the present day. The Japanese pet cricket culture, which emerged at least a thousand years ago, has practically vanished during the 20th century. Chinese cricket culture and cricket-related business is highly seasonal. Trapping crickets in the fields peaks in August and extends into September. The crickets soon end up at the markets of Shanghai and other major cities. Cricket fighting season extends until the end of autumn, overlapping with the Mid-Autumn Festival and the National Day. Chinese breeders are striving to make cricket fighting a year-round pastime, but the seasonal tradition prevails. Modern Western sources recommend keeping pet crickets in transparent jars or small terrariums providing at least two inches of soil for burrowing and containing egg-crate shells or similar objects for shelter.〔Amato, pp. 43–44.〕 A cricket's life span is short: Development from an egg to imago takes from one to two months. The imago then lives for around one month. Cricket hobbyists have to frequently replace aging insects with younger ones which are either specifically bred for cricket fighting or caught in the wild. This makes crickets less appealing as pets in Western countries. The speed of growth, coupled with the ease of breeding and raising larvae, makes industrial-grown crickets a preferred and inexpensive food source for pet birds, reptiles, and spiders. ==Cricket biology== True crickets are insects of the ''Gryllidae'', a cosmopolitan family of around 100 genera comprising some 800 species, belonging to the order Orthoptera.〔Gordh et al., p. 415.〕 Crickets, like other Orthoptera (grasshoppers and katydids), are capable of producing high-pitched sound by stridulation. Crickets differ from other Orthoptera in four aspects: Crickets possess three-segmented tarsi and long antennae; their tympanum is located at the base of the front tibia; and the females have long, slender ovipositors.〔John L. Foltz (1998). ("ENY 3005 Family Identification: Orthoptera: Gryllidae" ). University of Florida. Retrieved 2010-09-10.〕 The life cycle of a cricket usually spans no more than three months. The larvae of the field cricket hatch from eggs in 7–8 days, while those of Acheta domesticus develop in 11–12 days. Development of the larvae in a controlled, warm () farm environment takes four to five weeks for all cultivated species.〔Kompantseva et al., p. 103.〕 After the fourth or fifth larval instar the wingless larvae moult into the winged imago which lives for around one month.〔Laufer, p.4; Ryan et al., p. 4.〕 Crickets are omnivorous, opportunistic scavengers. They feed on decaying vegetable matter and fruit, and attack weaker insects or their larvae.〔Levchenko, p. 125, warns against uncontrolled feeding of crickets to spiders immediately before and during moulting. A cricket will eagerly attack a much larger but defenseless moulting spider.〕 A male cricket "sings" by raising his wing covers (tegmina) above the body and rubbing their bases against each other. The wing covers of a mature male cricket have protruding, irregularly shaped veins.〔 The scraper of the left wing cover rubs against the file of the right wing, producing a high-pitched chirp.〔Thomas J. Walker, (1999). ("House cricket – Acheta domesticus" ). University of Florida. Retrieved 2010-09-10.〕 Crickets are much smaller than the sound wavelengths that they emit, which makes them inefficient transducers, but they overcome this disadvantage by using external natural resonators. Ground-dwelling field crickets use their funnel-shaped burrow entrances as acoustic horns; ''Oecanthus burmeisteri'' attach themselves to leaves which serve as soundboards and increase sound volume by 15 to 47 times.〔Turner, pp. 161, 165–166, 171.〕 Chinese handlers increase the apparent loudness of their captive crickets by waxing the insects' tympanum with a mixture of cypress or lacebark tree sap and cinnabar. A legend says that this treatment was discovered in the day of the Qing Dynasty, when the Emperor's cricket, held in a cage suspended from a pine tree, was observed to develop an "unusually beautiful voice" after accidentally dipping its wings in tree sap.〔Laufer, pp. 16–17; Ryan et al., pp. 22, 34.〕 Entomologists from Ivan Regen onward have agreed that the principal purpose of a male cricket's "song" is to attract females for mating.〔Huber et al., p. 44.〕 Berthold Laufer and Frank Lutz recognized the fact but noted that it was not clear why males do it continuously throughout most of their adult lives, when actual mating doesn't take much time.〔Laufer, pp. 3–4; Ryan et al., pp. 3–4. Huber et al., pp. 44–46, explain that different species "sing" in different periods of the day or night, for no longer than three hours continuously.〕 More is known about the attractive mechanism of a cricket's song. Scientists exposed cricket females to synthesized "cricket songs", carefully varying different acoustic parameters, and measured the degree of females' response to different sounds. They found that although each species has its own optimal mating call, the repetition rate of chirp "syllables" was the single most important parameter.〔Huber et al., pp. 55–56.〕 A male's singing skills do not guarantee him instant success: other, silent, males may be waiting nearby to intercept the females he attracts.〔Huber et al., p. 46, describe this behaviour in ''Gryllus integer''.〕 Other males may be attracted by the song and rush to the singer just as females do. When another cricket confronts a singing male, the two insects determine each other's sex by touching their antennae. If it turns out that both crickets are male, the contact leads to a fight.〔Huber et al., p. 45.〕〔This is a simplified model of ''Teleogryllus commodus'' behaviour. Huber et al., pp. 48–54, discuss various other means of sexual recognition in different species.〕 Crickets, and Orthoptera in general, are model organisms for the study of male-male aggression, although females can also be aggressive.〔Judge and Bonanno, p. 1.〕 According to Judge and Bonanno, the shape and size of male crickets' heads are a direct result of selection through male-male fights.〔Judge and Bonanno, pp. 1, 7.〕 The fact that only males sing, and only males fight, means that females have little value as pets apart from breeding. Chinese keepers feed young home-bred females to birds as soon as crickets display sexual dimorphism.〔 There is one notable exception: males of ''Homoeogryllus japonicus'' (''suzumushi'' or ''jin zhong'') sing only in the presence of females, so some females are spared to provide company to the males.〔Laufer, pp. 4–5; Ryan et al., p. 5.〕 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「crickets as pets」の詳細全文を読む スポンサード リンク
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