Rice leaf beetle - Rice leaf beetle

An insect belonging to the family Chrysomelidae in the order Coleoptera of the class Insecta. Its Japanese name is the rice beetle, but because the larvae have the habit of putting muddy feces on their backs, this name is used in agricultural circles, and it is also called the muddy beetle. It is distributed throughout Japan, Sakhalin, the Korean peninsula, China, and Taiwan. Its body length is 4 to 4.5 mm and it is slim. Its body is black, and most of its prothorax and legs are reddish yellow. Its epiphytes are long, almost parallel on both sides, and have a blue luster. It appears from around May, and feeds on plants of the Gramineae family, such as rice, wild rice, and reeds, laying black eggs in clusters and covering them with mucus. Both adults and larvae feed vertically between the veins on the surface of leaves, leaving white feeding marks, but the larvae do the most damage. For this reason, it is well known as a pest of rice. It overwinters as a larva.

[Takehiko Nakane]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

昆虫綱甲虫目ハムシ科に属する昆虫。和名はイネクビボソハムシであるが、幼虫が泥状の糞(ふん)を背中にのせる習性があるので、農業関係ではこの名を用いるほか、単にドロオイムシともいう。日本全土および樺太(からふと)（サハリン）、朝鮮半島、中国、台湾に分布する。体長4～4.5ミリメートルで細形。体は黒色で、前胸と肢(あし)の大半が赤黄色。上ばねは長くて両側がほぼ平行で、青い光沢がある。5月ごろから現れてイネ、マコモ、アシなどイネ科植物を食べ、黒い卵を塊状に産み付けて粘液で覆う。成虫、幼虫とも葉の表面の葉脈の間を縦に線状に食べて白く食痕(しょくこん)を残すが、幼虫のほうが害がひどい。このためイネの害虫として有名である。幼虫で越冬する。

［中根猛彦］

出典　小学館　日本大百科全書(ニッポニカ)日本大百科全書(ニッポニカ)について　情報 | 凡例