Abstract
Aspects of the natural history and behavioral ecology of the spider wasp, Pepsis thisbe were studied in Trans Pecos, Texas with special emphasis on larval development and host interactions. Additional parameters studied include the physical dimensions of the egg, larval and adult size, fecundity, egg survivorship and duration of embryonic and postembryonic development as a function of temperature and relative humidity (RH), larval growth and behavior, the relationship between adult wasp and host sizes, and ontogenetic changes in larval feeding patterns. Eggs and larvae did not survive when exposed to xeric conditions (10% RH). Forty-one days were required to progress from egg to emerged adult at 3℃ and 70% RH.