Rate of oviposition by Culex quinquefasciatus in San Antonio, Texas, during three years.

Two artificial oviposition sites containing aged alfalfa pellet infusion were exposed to natural populations of Culex quinquefasciatus in San Antonio, Texas, for 3 years. Numbers of egg rafts were counted daily and compared to weather data from a nearby station. Egg rafts were generally most numerous in summer months, declining in fall and increasing in spring. Oviposition occurred in winter only when temperatures were high enough. A particularly severe winter in 1983-84 reduced winter activity, but was followed by a great increase in oviposition in late spring. In summer, increases of oviposition were correlated with rainfall 2 to 3 weeks before the time of oviposition. Rainfall at the time of oviposition appeared to decrease oviposition. On a seasonal basis, lack of rainfall in the summer of 1984 was correlated with a decrease in oviposition.