DEMOGRAPHIC PARAMETERS OF AUTOGRAPHA GAMMA (NOCTUIDAE) AFFECTED BY SUGAR BEET CULTIVARS

Autographa gamma (Linnaeus) (Lepidoptera: Noctuidae) is one of the important polyphagous pests of various crops in Iran and many countries of the world. The effect of eight commercial sugar beet cultivars (Peritra, Karolina, Paolita, Lenzier, Tiller, Ardabili, Persia and Rozier) on demographic parameters of A. gamma was determined under laboratory conditions (25 +/- 1 degrees C, 65 +/- 5% RH, a 16:8 h light-dark photoperiod) using age-stage, two-sex life table method. A delay in the developmental time of pre-adult was observed when larvae were fed on cultivar Rozier. The lowest net reproductive rate (R-0) was observed on cultivars Paolita and Persia. Also, the intrinsic rate of increase (r(m)) was the highest when larvae were reared on cultivar Karolina and the lowest when they were fed on cultivars Peritra, Paolita and Persia. The results of this study revealed that the Peritra, Paolita and Persia were the most unsuitable cultivars for population growth of A. gamma. The information obtained from this study could be used, along with other management tactics, to control of this pest by sowing resistant sugar beet cultivars.