The trophic position of the dragonfly Rhionaeschna variegata in the wetland food webs was analyzed in relation to the variation of its larval body size. The smaller R. variegata larvae experience high levels of cannibalism and intraguild predation by sympatric aquatic insects. The largest R. variegata larvae which survive predation reach the top of the trophic food web having a great impact on the survival of invertebrates and amphibian larvae.