Fig. 1. Effects of temperature and ambient oxygen partial pressure P_O2 on development of eggs of Manduca sexta. Eggs were exposed to experimental conditions from within 6 h of oviposition until hatching. Ten eggs were exposed to each combination of factors (240 eggs total), and all treatments were started simultaneously. (A) Fraction hatching in each combination of temperature and oxygen. (B) Total development time from oviposition to hatching, including only those that actually hatched. In all cases, standard errors were so small that they are hidden by their respective symbol.