Spider - Tanagumo

A general term for the family Arthropoda, Arachnida, and Araneidae. A typical example is the house spider Tegenaria domestica , which spins shelf-like webs in dark places such as corners of houses, with a tunnel-like dwelling at the back of the web. This species is found widely in temperate regions around the world, with a body length of 8 to 10 millimeters, brown, and a gray abdomen with faint net-like spots.

A species commonly seen in the wild is the grass spider Agelena limbata , also known as the nojitanagumo spider, which spins its webs on shrubs and hedges. Although it is often disliked as it ruins the aesthetic look, it is a beneficial insect that preys on pests that invade hedges. The small-spotted grass spider Cicurina japonica is a tiny yellow-white spider that lives in leaf litter or caves. Among the grass spiders, the species with the greatest variety and population is the yachigumo spider. They build tunnel-like dwellings under stones or in cuts in mountain paths. Their webs are not as large as those of the grass spiders and the nojitanagumo spiders, and they only spin small webs near the entrances. Some are distributed widely across the country, while others are distributed locally due to geographical isolation.

[Takeo Yaginuma]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

節足動物門クモ形綱真正クモ目タナグモ科の総称。代表的なのは、家屋内の隅などの薄暗い所に棚状の網を張るイエタナグモTegenaria domesticaで、棚網の奥にトンネル状の住居がある。世界の温帯地方に広く分布する種で体長8～10ミリメートル、褐色で腹部は灰色でかすかな網状斑(はん)がある。

　野外で普通にみられる種はクサグモAgelena limbataで、低木や生け垣などに網を張りノジタナグモともよばれる。美観を損なうので嫌われがちであるが、生け垣などにくる害虫を補食してくれる益虫である。コタナグモCicurina japonicaは、黄白色の微小なクモで落葉層や洞窟(どうくつ)内にすむ。タナグモの仲間で、とくに種類や個体数の多いのはヤチグモ類である。石の下や山道の切り通しなどにトンネル状住居をつくる。網はタナグモやクサグモのように大きくはなく、入口付近にわずか張るだけである。各地に広く分布するものから、地理的隔離によって局地的な分布をするものもある。

［八木沼健夫］

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