Yellow-spotted Skipper - Yellow-spotted Skipper

A butterfly belonging to the order Lepidoptera and the family Hesperiidae. It is distributed from Hokkaido to Kyushu, but its numbers are generally low in colder regions. Nakanoshima in the Tokara Islands is the southern limit of its known distribution in Japan. Outside of Japan, it is found in the Korean Peninsula, Primorsky Krai of the Russian Federation, and China. Its wingspan is about 30 millimeters. The shape of the wings differs between males and females, with females having round forewings, but the color and markings are almost the same for both sexes, with black and yellow mottled patterns. In cold regions, it emerges once a year (July and August), and in warm regions it emerges twice a year (spring type June and July, summer type August and September), in which case the summer type is noticeably smaller than the spring type. The larvae feed on grasses of the Gramineae family, such as green foxtail, Japanese silver grass, crabgrass, goosegrass, bamboo grass, and jozudama, but sometimes attach to various types of bamboo, and the larvae make nests by rolling up the leaves of these plants and hiding there. The overwintering form is a larva.

[Takashi Shiramizu]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

昆虫綱鱗翅(りんし)目セセリチョウ科に属するチョウ。北海道から九州にかけて分布するが、寒冷地では一般にその数が少ない。吐噶喇(とから)列島中之島が日本における既知分布の南限。外国では朝鮮半島、ロシア連邦の沿海州、中国に分布する。はねの開張30ミリメートル内外。はねの形は雌雄によって異なり、雌は前ばねが丸いが、色彩や斑紋(はんもん)は雌雄ほぼ同様で、黒と黄のまだら模様をもつ。寒冷地では年1回の発生（7、8月）、暖地では年2回の発生（春型6、7月、夏型8、9月）、この場合には夏型は春型に比べて目だって小さい。幼虫の食草はエノコログサ、ススキ、メヒシバ、オヒシバ、チヂミザサ、ジュズダマなどのイネ科の雑草であるが、ときに各種のササ類にもつき、幼虫はこれらの植物の葉を巻いて巣をつくり、その中に潜んでいる。越冬態は幼虫である。

［白水　隆］

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