Seasonal development of the navel orangeworm. Egg laying by navel orangeworm varies from year to year and from district to district. For the egg stage, the denser dots indicate the period during which egg laying typically peaks. The date hull split begins can also vary from one year to the next, depending upon temperature. The fourth flight and the partial fourth generation are more common in southern portions of the Central Valley, especially in years with above average temperatures.

Illustration from Integrated Pest Management for Almonds. UC ANR Publication 3308.