Menemerus fulvus

Menemerus fulvus is a medium-sized, distinctly flattened jumping spider. Females reach a body length of about 8–10 mm and males about 7–9 mm. The body is dark beneath a dense covering of short grey and white hairs, so that living animals often appear pale grey; the sides of the body are darker. The carapace is low and flat with an almost straight front margin, and the legs are short and somewhat flattened. Conspicuous long white hairs on the pedipalps give the impression of a white beard or moustache, a feature reflected in the spider's Japanese and Chinese common names. As in other members of the genus, the species is most reliably separated from its congeners by the copulatory organs: the form of the male palpal bulb and tibial apophysis, and the internal structure of the female epigyne.

The World Spider Catalog gives the range of M. fulvus as India to China and Japan. In China it is recorded from a wide range of provinces, including Hebei, Jiangsu, Anhui, Jiangxi, Zhejiang, Henan, Hubei, Hunan, Fujian, Guangxi, Guizhou, Sichuan, Yunnan and Hainan, as well as Taiwan. In Japan it occurs from Honshu south through Shikoku and Kyushu to the Ryukyu Islands. It is also recorded from Korea and from parts of Southeast Asia, including Malaysia.

Menemerus fulvus is strongly synanthropic and is most often found on the exterior walls, shutters and boundary walls of houses, though it also occurs on tree trunks, on rocks along the coast and in open habitats generally. Individuals build a silken sac-shaped retreat in a crack or crevice and range over a territory centred on it. Like other salticids it does not build a capture web, instead hunting by sight during the day and stalking or ambushing small insects before seizing them in a short leap. Males perform a display in which the first pair of legs is raised towards another spider. The display is used both in courtship and in contests between males. The species is common in rice, cotton and other agricultural landscapes across China, where it has repeatedly been catalogued among the natural enemies of crop pests. It is harmless to humans.