Trichonephilia fenestrata is a species of nephilid spider known from Africa. It was first described by Tamerlan Thorell in 1859 as Nephila fenestrata, and was later moved to Trichonephila when it was elevated to genus status by Kuntner in 2019. Three subspecies are known from different parts of Africa. Males of this species often autotomize their legs as a counter-adaptation to the sexual cannibalism of females.
The female, with a body length of 20-30mm, is almost entirely black and the first, second and fourth pairs of legs have a brush of bristles on the tibia. The third pair of legs is the shortest with no brush. The abdomen is elongated (long oval) and is cream to yellow with the caudal section (towards the tail end) black or blue with speckles infusing forward into the yellow. There is a huge variation of abdominal patterns with the amount of black or blue on the abdomen. The key feature to identify this species is the black legs and window pattern ventrally.
Nephila fenestrata, the Black-legged nephila, occurs over most of South Africa, excluding the arid central and western regions, and is the only species of Nephila to occur in the Western Cape. Since 2002 this species has crossed over the Hottentots Holland mountain range and is now the most commonly seen orb-web spider on the Cape Peninsula. It can be seen from January till the end of June or even to the end of August, usually in forested areas or near areas with trees allowing for suspension of their large orb-webs. In Kirstenbosch and Newlands Forest one can easily see 30 or more of these spiders on a walk.
