تأثير پنج رقم كلزا در ميزان بقاء و قدرت باروري شته مومي كلم Brevicoryne brassice (Hom. : Aphididae) در مرحله گلدهي

Nutritional effects of five different oilseed rape cultivars on the survival rate and fecundity of cabbage aphid Brevicoryne brassicae, (Horn. :Aphididae) at flowering stage

Cabbage aphid is one of the most important insect pests of oilseed plants in most parts of Iran, which causes economic losses on the crop. In the present study, the biological responses of the cabbage aphid fed on 5 rapeseed cultivars namely Uorica, Hayola 401, Hayola 308, Parkland and Pf (7045 ,91) was investigated at flowering phenological stage, under glasshouse conditions of 23 ±1°C , 70±5% R.H. and photoperiod of 16:8(L : D) periods. Antibiosis was determined by studying the percentage survival of the nymphs, duration of their development time, fecundity (total number of progeny per female produced within the first 10 and 15 days reproductive period) and finally calculating the relevant intrinsic rate of natural population increase (rm value). The ANOVA of the data indicated that, there were significant differences (p < 0.05) between the cultivars. At flowering stage, the highest mean rm value (0.3159±0. 0389 and 0.3078±0.0335) was estimated for rearing on Parkland with the lowest (0.1478±0.0167 and 0.1440±0.0195) on the PF(7045.91) within the first 10 and 15 day periods respectively. Thus in this study, Parkland is regarded as the most susceptible and PF(7045.91) as the most resistant variety in relation to the aphid.