Jokaibon - Jokaibon

It is an insect belonging to the family Canthariidae in the order Coleoptera of the class Insecta. It is distributed throughout Japan, appearing from the end of April and often found on flowers and leaves. Its body length is around 15 mm. It is yellowish brown with a large black pattern on its head and the back of its pronotum, and depending on the region, the meeting point or tip of the epiphytes is black, and sometimes the entire body is black. It is quite long with both sides parallel to each other. Adults prey on other insects but also eat nectar, females lay eggs underground, and the larvae are also carnivorous.

The soldier beetle (Cantharidae) is distributed widely around the world, and several thousand species are known, of which about 70 are native to Japan, but it is thought that there are more than 100 species. The body length is about 3 to 30 mm. The body is thin, flat, and angular, with bulging shoulders, but is weak. Most are yellow, red, or black, and some species have metallic-colored upper wings. They are mainly found on leaves and come to flowers, but are carnivorous and catch other insects, and some also eat pollen and nectar. The larvae live in fallen leaves or under the bark of trees, and eat small insects and insect eggs. In Japan, in addition to the soldier beetle, the blue soldier beetle Themus cyanipennis , which is common in mountainous areas, and the golden soldier beetle T. episcopalis , which is found in the Kinki region and west, are large and noticeable, but there are far more medium-sized and small species, such as the lesser soldier beetle, the neck-ball soldier beetle, and the common soldier beetle.

[Takehiko Nakane]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

昆虫綱甲虫目ジョウカイボン科に属する昆虫。日本各地に分布し、4月末ごろから現れ、花上や葉上に多い。体長15ミリメートル内外。黄褐色で頭・前胸背面の大紋は黒く、上ばねは地域により会合部あるいは先端が黒く、全体が黒いこともある。形はかなり長くて両側が平行する。成虫はほかの虫を捕食するが花蜜(かみつ)も食べ、雌は地中に産卵し、幼虫も肉食である。

　ジョウカイボン科soldier beetle／Cantharidaeは世界に広く分布し、数千種が知られており、そのうち日本産は70種ぐらいであるが、100種以上産すると思われる。体長3～30ミリメートルぐらい。体は細形で平たくて角張り、肩が張っているが、軟弱である。黄・赤・黒の色のものが多く、上ばねが金属色の種もある。おもに葉上にみられ、花にもくるが、肉食でほかの虫もとらえ、一部は花粉や蜜も食べる。幼虫は落ち葉の中や樹皮下などにすみ、小昆虫や虫の卵などを食べる。日本ではジョウカイボンのほか、山地に多いアオジョウカイThemus cyanipennisや近畿地方以西にいるキンイロジョウカイT. episcopalisなどが大形で目だつが、種数は中・小形のほうがはるかに多く、ヒメジョウカイ、クビボソジョウカイ、コバネジョウカイなどがある。

［中根猛彦］

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