The ovipositional cycle of Psorophora columbiae was bimodal when gravid females were exposed to natural climatic conditions over three separate 24 hr periods. Peak egg deposition (49.8 eggs/cage) occurred during the first 24 hr period after sunset. Other cages of Ps. columbiae females were exposed to aliquots of soil with various moisture levels by weight. Average numbers of eggs deposited per cage in soil at 0, 20, 40, 60 and 80% moisture by weight differed significantly (P < 0.001) with 2.2, 30.2, 89.8, 28.3 and 14.0 eggs, respectively. When the intervals between moisture levels were reduced to 10% and caged mosquitoes were exposed to soil at 30, 40, 50, 60, 70 and 80% moisture, significant differences (P < 0.008) occurred among the mean numbers of eggs per moisture level (125.8, 188.6, 176.9, 39.6, 46.3, and 31.5, respectively).
Contributor Notes
1 Diptera: Culicidae
2 This research was conducted as a cooperative effort between the State Agricultural Experiment Stations of Arkansas, California, Louisiana, Mississippi, and Texas and the Agricultural Research Service, USDA as part of the USDA/CRS Southern Regional Project S-122 on the Biology, Ecology, and Management of Riceland Mosquitoes in the Southern Region.