Vampire Jumping Spider

As juveniles, all E. culicivora are grey-brown in color, both on their bodies and face. Adult males have blood-red faces and white-hair patches above the principal eyes and at the side of the clypeus and on palp tibia. Juveniles and adult females have grey-brown faces, but adult females have a faint red tint. It is rare for adult females and juveniles to have white patches. Body lengths of males range from 3 mm to 6 mm, whereas females range from 4 mm to 7 mm.

Evarcha culicivora is found only around Lake Victoria in Kenya and Uganda. This area is full of a variety of insect life and has a large number of Chaoboridae midges. These lake flies are similar in size and appearance to Anopheles mosquitos, common prey of E. culicivora, but E. culicivora disregards their presence as well as the majority of all other insects present. This species builds nests, where it primarily resides. Nests are built within closed spaces such as tree trunks or walls of buildings and are often made of dead foliage such as leaves. It hides in the grass or other plants close to the ground when it is quiescent. When it is hunting, it will go to more exposed locations such as the walls inside some mosquito-infested houses.

In female-female and male-male interactions, the intruder encroaches when the resident is quiescent in the nest. The intruder usually probes first and then pushes its face into the silk, chewing and tugging the silk. The resident pulls on the silk as a response. For male-female interaction at the nest, see the mating section. Observations have been made of males cohabiting with females. In cases of cohabitation, the two silk tubes are woven together and the two doors of the two chambers are aligned together. See the Courtship section for more information on how cohabitation plays a role in courtship.