Moisture content of soil appears to be one of the more important factors that determine whether or not, and to what extent, Psorophora columbiae (Dyar and Knab) females will use a particular site for oviposition in Texas ricelands. Gravid females of this species exposed to various levee situations in the laboratory deposited the great majority of their eggs on soil that was relatively muddy (i.e., on soil whose moisture content ranged between 75% field capacity to just above field capacity). Conditions observed at field sites in Brazoria County, Texas tend to support laboratory findings.