Theridiidae Rhomphaea

Rhomphaea sinica (Zhu & Song, 1991)

Black Diamond Boomerang Spider

This species differs from all known Rhomphaea species in Singapore by its small size (3-4 mm) and characteristic markings on the dorsum: an irregular longitudinal black stripe in front, and a diamond-shaped black spot slightly behind. It is easily recognised by having five tit-like structures at the apex of the abdomen, of which two have tiny sclerotised tips. (These may not be conspicuous in some specimens as they may be retracted.) The eyes are mounted on a hemispherical tubercle. The carapace is contrastingly coloured in black and yellow. The extent of the yellow area may vary between the sexes, but there is always a median yellow stripe running over the thoracic (posterior) hump of the male and female carapace.

Compared with other Singapore Rhomphaea, the male palps are exceptionally long, with the palpal femur almost 1.6 times longer than the carapace.