prof. Mgr. Stanislav Pekár, Ph.D.
prof. Mgr. Stano Pekár, Ph.D.
Stenophagy (narrowdiet breadth) represents an extreme of trophic specialization in carnivores, but little is known about the forces
driving its evolution. We used spiders, the most diversified group of terrestrial predators, to investigate whether stenophagy
(1) promoted diversification
(2) was phylogenetically conserved and evolutionarily derived state
and (3) was determined either
by geographical distribution and foraging guild. We used published data on the prey of almost 600 species. Six categories of
stenophagy were found: myrmecophagy, araneophagy, lepidopterophagy, termitophagy, dipterophagy, and crustaceophagy. We
found that the species diversity of euryphagous genera and families was similar to stenophagous genera and families. At the
family level, stenophagy evolved repeatedly and independently.Within families, the basal condition was oligophagy or euryphagy.
Most types of stenophagy were clearly derived: myrmecophagy in Zodariidae
lepidopterophagy in Araneidae
dipterophagy in
Theridiidae. In contrast, araneophagy was confined to basal and intermediate lineages, suggesting its ancestral condition. The
diet breadth of species from the tropics and subtropics was less diverse than species from the temperate zone. Diet breadth was
lower in cursorial spiders compared to web-building species. Thus, the evolution of stenophagy in spiders appears to be complex
and governed by phylogeny as well as by ecological determinants.
Pekár S., Coddington J. A. & Blackledge T. (2012): Evolution of stenophagy in spiders (Araneae): evidence based on the comparative analysis of spider diets. Evolution 66 (3): 776–806.