Cucumber Beetle - Cucumber Beetle

It is an insect belonging to the family Chrysomelidae in the order Coleoptera of the class Insecta. It is widely distributed in Honshu, Shikoku, Kyushu, the Ryukyu Islands, Taiwan, and the Korean Peninsula, and is a pest of cucumbers. Its body length is 7 to 8 mm. It is orange-yellow in color, with its hind thorax, abdomen, mid legs, and hind legs being black. There is a deep horizontal groove on the pronotum, and the hind thorax is slightly wider at the back. The adult appears around April to May, and eats the leaves to make them look like a net. It is also known as the cucumber fly because it flies well. Its eggs are laid in the soil around the roots of cucumbers, and the larvae bite into the roots to cause damage. It pupates in the soil, and overwinter as an adult. It often gathers in gaps in stone walls and around grass roots. Individuals in the Ryukyu Islands are generally reddish, but there is also the slightly larger A. bicolor with a similar body color.

[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。本州、四国、九州、南西諸島および台湾、朝鮮半島に広く分布しており、ウリ類の害虫。体長7～8ミリメートル。橙黄(とうおう)色で、後胸と腹部、中肢(ちゅうし)と後肢は黒い。前胸背には深い横溝があり、上ばねは少し後方が広い。成虫は4～5月ごろから現れ、葉を食べて網目のようにする。よく飛ぶのでウリバエという異名がある。卵は土中のウリの根のあたりに産み付けられ、幼虫は根に食い入って加害する。蛹(さなぎ)になるのも土中で、成虫になって越冬する。この際、石垣のすきまや草の根ぎわなどに集まることが多い。琉球(りゅうきゅう)諸島の個体は一般に赤みが強いが、よく似た体色でやや大形のフタイロウリハムシA. bicolorもいる。

［中根猛彦］

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