Does fragmentation of Urtica habitats affect phytophagous and predatory insects differentially

摘要: Effects of habitat fragmentation on the insect community stinging nettle (Urtica dioica L.) were studied, using 32 natural patches different area and degree isolation in an agricultural landscape. Habitat reduced species richness Heteroptera, Auchenorrhyncha, Coleoptera, abundance populations. reduction did not affect all equally. Monophagous herbivores had a higher probability absence from small than (monophagous polyphagous) herbivore species, percentage monophagous increased with area. Abundance population variability negatively correlated could both be used as predictor occupied habitats. Species (positively) area, while predators (negatively) isolation. In logistic regressions, only explained by (in 4 out 10 species) predator 3 14 species). Presumably because instability higher-trophic-level populations dispersal limitation, more affected herbivores, they differ respect to or variability. Thus increasing connectivity landscape should primarily promote