Short-Term Daily Emergence of Adult Midges (Diptera: Chironomidae) from a Natural Lake and an Artificial Reservoir1

Abstract

Daily emergence of adult Chironomidae in a lake and an artificial reservoir in Florida was sampled at 24-h intervals during spring and summer 1980 and summer 1981. Changes in water temperature during the sampling periods were recorded. Linear population trends of a species with time were examined by multiple linear regression. Temporal relationships of emergence periodicity within a species, between species, and between a catch of a species and daily water temperature were examined by autocorrelation and standard correlation analyses. Glyptotendipes paripes Edwards and Chironomus decorus Johannsen in the reservoir, and G. paripes and C. crassicaudatus Malloch in the lake, were quantitatively important and emerged on a daily basis at 18.5 to 30.0°C water temperatures. Trends of adult emergence of all species in relation to Julian day were inconsistent. Some significant autocorrelations and standard correlations existed, but all the correlation coefficient values were less than 0.66. From the daily emergence of the species studied, it can be suggested that their oviposition in central Florida lakes takes place almost on a daily basis at 18.0 to 30.0°C water temperatures, and several asynchronous generations of each species develop resulting in their asynchronous emergence.