Measurement of threshold temperature required for nymphal stage development of Aphis fabae Scop.

Abstract

The aim of this investigation was to measure the threshold temperature required for nymphal stage developments of Aphis fabae Scop., Which was used as prediction of biological activities of this insect, in order to control it in field. The results showed that the threshold temperature degree required for nymphal stage developments was 5.65C, and under this temperature no development was occurred. Also, the result showed that the average units of degree- day required for the four nymohal stage developments were 25.64, 33.33, 38.46 and 45.45 degree- day respectively.