Most bloodthirsty spider

The most bloodthirsty spider is the vampire spider Evarcha culicivora, a species of jumping spider restricted to the environs of Lake Victoria in Kenya and Uganda, eastern Africa. Its diet is also highly restricted, because it feeds not only specifically upon female blood-drinking Anopheles mosquitoes (most commonly the malaria-transmitting species A. gambiae), but in addition almost exclusively only upon specimens of these insects that have newly engorged themselves with blood from a host individual. Male Anopheles mosquitoes do not feed upon blood, only nectar and other sources of sugar, so the vampire spider does not feed upon them.

The vampire spider is the first-known predator to consume vertebrate blood via this indirect, mosquito-mediated manner, as well as the first to select its prey based upon what and whether it has eaten. Moreover, studies have revealed that it is more successful in selecting mosquitoes that still contain the blood that they have imbibed via smell than by sight, even though, like other jumping spiders, it does have excellent vision. It was formally described and named as a new species in 2003.