Hiding among traps? Mortality of early instar odonate larvae in the presence of bladderwort plants

Abstract

We investigated the effects of the presence of bladderwort plants on survival of early instar larvae of one coenagrionid and two libellulids in laboratory experiments. In all three species survival was reduced compared to treatments with a non-carnivorous submerged plant, with effective mortality that could be related to bladderwort being 19–45% dependent on the prey species. Individuals of all species were found in capture bladders. We also recorded the microhabitat use of the early instar larvae and found that the species with highest use of vegetation had highest mortality due to bladderwort. We conclude that bladderwort may have effects on odonate larvae that translate into natural conditions and we discuss factors that may affect predation by bladderwort on odonates in the field.

Keywords: Crocothemis erythraea, Ischnura elegans, Libellula quadrimaculata, microhabitat use, predation, Utricularia vulgaris, dragonfly, Odonata

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