ESTIMATING THRESHOLD TEMPERATURE AND HEAT UNIT ACCUMULATION REQUIRED FOR MEADOW SPITTLEBUG (HOMOPTERA, CERCOPIDAE) EGG HATCH

A procedure for estimating the threshold temperature for egg development of the meadow spittlebug (P. spumarius L.) is discussed. Utilizing both laboratory and field data [alfalfa meadow], heat unit accumulations (HU) based on this threshold were used to calculate the length of the egg hatching period to predict egg hatch in the field. An accumulation of 120 HU (.degree. C) above a threshold of 6.5.degree. C resulted in initial egg hatch, but the egg hatching period was not completed until 330 HU were accumulated.