Quantitative Bionomics of Culex Nigripalpus (Diptera: Culicidae) Populations In Florida: 2. Distribution, dispersal and survival patterns1

Abstract

Culex nignpalpus larvae were marked with radioactive phosphorus-32 during the 4th instar and the marked adults were released in the field to study their distribution, dispersal, and survival patterns. Released adults were collected in proportionately larger numbers in oak hammocks than in other areas, suggesting that this is a woodland species. Four broods, each with differing nutritional experiences (at emergence, after 24 h starvation, fed on sucrose for 24 h, and fed on sucrose and blood) were released in the Tiger Hammock study area, Florida, from August to October 1976; 4682 (1.87%) of the 250,000 mosquitoes released were recaptured in oak hammocks. Substantially fewer (0.8%) adults were recaptured from a brood whose adults were starved for 24 h prior to release than from the other 3 broods (1.86% to 3.01%). Of the recaptured mosquitoes, 82.4% were taken within a 0.4-km radius around the release point (Tiger Hammock study area) and the other 17.6% within a radius of 0.4 to 1.2 km. After release, marked adults soon moved predominantly to oak hammock areas. They were recovered there up to 12 days during each experiment. After the first 2 days of release, the daily survival rate (p) for females varied from 0.66 to 0.79 in the 4 experiments, with an average of 0.72. The daily survival rate for males was substantially higher, with an average of 0.84 for the 4 experiments. These experiments suggest that the majority of Cx. nigripalpus from any 1 brood probably survive less than 14 days after emergence during normal summer weather conditions of central Florida.