Influence of Selected Sediment Physical Parameters on Spatial Distribution of Larval Glyptotendipes paripes (Diptera: Chironomidae) in Three Central Florida Lakes

Spatial distribution of larvae of the pestiferous midge, Glyptotendipes paripes Edwards in relation to selected sediment physical conditions was monitored for 1 year in 3 eutrophic central Florida lakes. Two of these lakes (Monroe and Wauburg) supported a distribution pattern of high densities on the firm peripheral sediments of the lakes, while the third lake (Eustis) displayed the opposite pattern of higher densities in the soft sediments at the lake center. Linear and multivariate analyses revealed that the presence of larval fecal pellets and larger sized particles in the Lake Eustis sediments were strongly associated with the latter distribution pattern. In all 3 lakes, sediment dry weight, and particle size composition were not significantly associated with larval density. In these lakes, G. paripes distributions appear to be strongly influenced by the physical structure of the soft, organic sediments at the lake center; sediments with large particles and considerable accumulation of fecal pellets would support higher densities of the larvae which also exist in relatively firm sediments close to the lake margin. This provides valuable information to lake managers attempting population management of this nuisance species.