Embryo Development and Egg Hatching of Sitona crinitus Herbst (Coleoptera: Curculionidae) under Constant Temperature Regimes

The effect of constant temperatures (5, 8, 10, 15, 20, 25, 30 and 35°C) on embryo development period
and percentage of egg hatching of S. crinitus Herbst was determined in the laboratory. A significant negative
relationship (P < 0.05; r = - 0.84) was found between temperature and embryo development. At temperatures
below 35°C there was no significant effect on egg hatching. At 30°C, the embryo development period was the
shortest, 7 days; whereas at 8°C this parameter was the longest, 69 days. At 35°C eggs became dry and
deformed. Temperatures below 10°C induced quiescence in the egg stage. This information is useful for
predicting S. crinitus infestation levels.