Ground Beetle - Caterpillar

A general term for medium to large sized insects in the broad Carabidae genus Carabus , order Coleoptera, class Insecta. There are several hundred species worldwide, but they are mainly distributed in the Palearctic region, with only a few species living in North America. The body is usually long, and the elytra is ovoid or long ovoid, or sometimes spindle-shaped. The pronotum is narrower than the elytra, and the head protrudes forward and is even thinner than the pronotum. With the exception of some species, the hind wings have degenerated into small pieces, making them unable to fly. This limits movement and causes geographical isolation, resulting in regional differentiation and variation in body shape, surface structure, color tone, etc., with many subspecies and types being distinguished within each species.

They generally live on the ground, are active at night, and are carnivorous, preying on snails, earthworms, and other insects, especially the larvae of lepidoptera. Species such as the Japanese Snail Guardian, which have a long body and a particularly thin cephalothorax, are thought to have adapted to feeding by inserting their heads into snail shells. Eggs are laid in the soil, and the larvae, like the adults, are carnivorous, hiding under stones or fallen leaves during the day and being active at night. The hatched larvae pupate in the soil. The adults hibernate in the soil, sometimes in dead trees, so they can be collected by digging in cliffs along roads in winter. They can also be collected in summer using molasses or carrion traps.

This genus has many beautiful metallic-colored species, and there are collectors all over the world. There are over 20 species of ground beetles in Japan, but they have been given over 100 subspecies and type names, including beautiful species such as the Ainu Kin ground beetle, the Ootorio samushi, and the Tsushima Kaburi Modoki, as well as the Maimai Kaburi and Kuronaga ground beetles, which are only found in the Japanese archipelago.

The family Carabidae includes two species that are close to ground beetles, the rough-edged ground beetle and the rough-legged ground beetle, as well as five other species (subfamilies): the round-headed ground beetle, the mountain killifish, the false tiger beetle, the stone beetle, and the horned ground beetle.When the family is used in a broader sense, it also includes the families of hairless ground beetles, gourd beetles, stag beetles, dung beetles, and sometimes tiger beetles.

[Takehiko Nakane]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

昆虫綱甲虫目オサムシ科の昆虫のうち、広義のオサムシ属Carabusに含まれる中・大形種の総称。世界に数百種を産するが、主として旧北区に分布し、ごく一部の種が北アメリカにすむ。体は普通長めで、上ばねは卵形ないし長卵形、ときに紡錘形。前胸は上ばねよりも幅が狭く、頭は前方に突き出し、前胸よりさらに細い。後翅(こうし)は一部の種を除いて退化し、小片状になっているので飛べない。このため移動が制限され、地理的な隔離が生じ、地域的な分化や変異が、体形、体表構造、色調などにみられ、種内にも多くの亜種や型が区別されている。

　一般に地表で生活して夜間に活動し、肉食で、カタツムリ、ミミズ、他の昆虫、とくに鱗翅類(りんしるい)の幼虫などを捕食する。体が長く、頭胸部がとくに細く伸びたマイマイカブリのような種類は、カタツムリの殻内に頭を突っ込んで食べるのに適応したものと思われる。卵は土中に産み付けられ、幼虫も成虫と同じく肉食で、昼間は石や落ち葉などの下に隠れて夜間活動する。孵化(ふか)した幼虫は土中で蛹化(ようか)する。成虫は土中、ときには枯れ木内で集まって越冬するので、冬季に道沿いの崖(がけ)を掘って採集する方法がある。また、夏は糖蜜(とうみつ)や腐肉トラップで採集することができる。

　この類は金属色の美しい種が多いので、世界各地に収集愛好家がいる。日本にいるオサムシは20種余であるが、それらには100に及ぶ亜種名や型名が与えられており、アイヌキンオサムシ、オオルリオサムシ、ツシマカブリモドキなどの美麗種や、日本列島にだけみられるマイマイカブリ、クロナガオサムシなどが含まれる。

　オサムシ科Carabidaeには、オサムシ類に近いカタビロオサムシ、セダカオサムシの2類のほかに、マルクビゴミムシ、ミヤマメダカゴミムシ、ハンミョウモドキ、カワラゴミムシ、ツノヒゲゴミムシの5類（亜科）を含み、科をさらに広い意味で用いるときには、ヒゲブトオサムシ、ヒョウタンゴミムシ、セスジムシ、ゴミムシ、ときにはハンミョウの各科をも包含する。

［中根猛彦］

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