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All instars of larval Coquillettidia perturbans were found in the same habitats, but early instar larvae were more aggregated than later instars. Larvae were most numerous in areas dominated by arrow-arum (Peltandra virginica) and maidencane (Panicum hemitomon), less so in areas dominated by sedges (Carex spp.) and miscellaneous mixed vegetation, and least abundant in pickerelweed (Pontederia cordata) areas. Larvae were uncommon in open water or in areas dominated by small floating plants such as water fern (Salvinia rotundifolia), duckweekd (Lemna minor) and mosquito fern (Azolla caroliniana). Larval concentrations were greatest in water 35-70 cm deep. There was also a tendency for them to concentrate in areas beyond 25 m from shore. Larvae were log-normally distributed in favorable sites and became progressively more aggregated as sites became less favorable.

Habitat characteristics were examined in two marshes and the littoral zones of two lakes in central Florida to determine their effect on the density and distribution of Coquillettidia perturbans. Larval and water samples were collected and habitat characteristics were recorded at monthly intervals for one year. Several significantly different physicochemical parameters were found between the marshes and lakeshores. Sites with dissolved oxygen less than 1.5 mg/liter (from October through May), pH less than 5.2, total alkalinity less than 6.0 mg CaCO3/liter, and orthophosphate less than 0.25 mg/liter were associated with significantly higher concentrations of Cq. perturbans. Arrow-arum, caric sedge, and maidencane were also associated with higher numbers of Coquillettidia.