Egg and 1st-instar survival as a function of soil texture and moisture was estimated under laboratory conditions. These stages were found to be resistant to extreme moisture conditions in various types of soils. Delays in egg development were observed particularly in saturated soils. These results are used in developing a mathematical model of survival of the early instars under variable moisture conditions, and simulations are compared with field data. Field survival was highly variable and correlated only partially to model outputs. Probable causes of the discrepancies are discussed.