Mosquito-terminator spiders and the meaning of predatory specialization

Many spiders eat mosquitoes, but a spider is not automatically a mosquito specialist if it eats mosquitoes, or even if it primarily eats mosquitoes. Instead, specialization pertains to predators being adaptively fine tuned to specific types of prey. It is important to keep this basic meaning of specialization conceptually distinct from diet breadth (stenophagy versus euryphagy), adaptive trade-offs and other sister topics. Here we review the biology of Evarcha culicivora Wesolowska & Jackson 2003 and Paracyrba wanlessi Zabka & Kovac 1996 (Salticidae), two spider species that can be characterized, in their own individual ways, as being mosquito specialists. However, simply calling these species mosquito specialists can be misleading. Details matter, with some of the most important of these details pertaining to the different ways E. culicivora and P. wanlessi classify mosquitoes. The way these species classify, and specialize on, mosquitoes includes fine-tuned prey-choice behavior, special feature-detection mechanisms, deployment of selective attention and other behavioral and cognitive capacities that can be understood only on the basis of appropriately designed experiments.