Ecological versus phylogenetic determinants of trophic associations in a plant-leafminer-parasitoid food web.

Specialized trophic interactions in plant-herbivore-parasitoid food webs can spur "bottom-up" diversification if speciation in plants leads to host-shift driven divergence in insect herbivores, and if the effect then cascades up to the third trophic level. Conversely, parasitoids that search for victims on certain plant taxa may trigger "top-down" diversification by pushing herbivores into "enemy-free space" on novel hosts. We used phylogenetic regression methods to compare the relative importance of ecology versus phylogeny on associations between Heterarthrinae leafmining sawflies and their parasitoids.

The Eurasian species of Xyela (Hymenoptera, Xyelidae): taxonomy, host plants and distribution.

The 28 Eurasian species of Xyela Dalman, 1819 are revised based on material of ca 7,500 imagines including about 10 % reared specimens. Larvae of Eurasian Xyela usually are monophagous and feed inside the staminate cones of pines (Pinus spp., Pinaceae).

Phylogenetics and evolution of host-plant use in leaf-mining sawflies (Hymenoptera: Tenthredinidae: Heterarthrinae).

The habit of mining within leaves has evolved convergently in numerous plant-feeding insect taxa. Many leaf-mining groups contain a large number of species with distinct feeding preferences, which makes them highly suitable for studies on the evolutionary history of host-plant use and on the role of niche shifts in speciation. We aimed to clarify the origin, classification, and ecological evolution of the tenthredinid sawfly subfamily Heterarthrinae, which contains c.

Defense by volatiles in leaf-mining insect larvae.

The defense strategy of an insect toward natural enemies can include a trait that appears at first sight to contradict its defensive function. We explored phylogeny, chemistry, and defense efficiency of a peculiar group of hymenopteran sawfly larvae where this contradiction is obvious. Pseudodineurini larvae live in leaf mines that protect them from some enemies.