243 - UV or not UV: Prey Recognition and Crypsis in the Pigmented Larvae of Toxorhynchites

Abstract: The predatory mosquito larvae of Toxorhynchites sp. display a colorful, red-purple cuticular pigment despite being exclusively ambush predators in murky, stagnant water contained in tree holes or artificial containers. Vision tests using prey mosquito larvae dyed red or blue and set upon white or black backgrounds were not significant. But dying prey with UV absorptive or UV reflective pigments instigated significant changes in attach frequency with prey items. Results varied depending on if lighting conditions were artificial, in full natural lighting, or in a dark, artificial tree hole. To evaluate defensive qualities of the pigmentation for Tx. r. septentrionalis, assays were conducted with the facultative mosquito predator Sabethes cyaneus, the western mosquitofish, or Toxorhynchites conspecifics that were set upon either normal or leucistic color morphs of Tx. r. setpentrionalis. We believe larval pigmentation confers some sort of defensive function both for prey items and for conspecifics when discussing Tx. r. septentrionalis. Furthermore, the interactions seem linked to UV emission spectra.