Jabraeil Razmjou - Department of Plant Protection, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.
Mahdieh Jafary - Department of Plant Protection, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.
Ehsan Borzoui - Department of Plant Protection, Faculty of Agriculture and Natural Resources, University of Mohaghegh Ardabili, Ardabil, Iran.

The antibiosis, host preference in free-choice situation, and digestive enzyme activity of Brevicoryne brassicae L. (Hemiptera: Aphididae) were evaluated in the laboratory (۲۵ ± ۱ °C, ۶۰ ± ۵% R. H. with a ۱۴-h day) on nine host plants: broccoli, canola (leaf, flower, and pod), cauliflower, kohlrabi, radish, red cabbage and white cabbage. The antibiosis test was based on life table parameters and the experiment started with ۵۰ replicates for each host plant using clip cages. The immature survival varied from ۳۴% on red cabbage to ۷۸% on cauliflower. The viviparous aphids reared on rapeseed (flower) had the highest GRR and R۰ values, and those on red cabbage had the lowest GRR and R۰ values. Also, aphids reared on rapeseed (flower) had significantly higher rm value. The lowest rm value was obtained when individuals fed upon red cabbage. In host preference experiment, rapeseed (leaf) attracted the significantly higher number of adults as opposed to radish, which attracted the lower number of adults. Females who came from nymphs reared on rapeseed (flower) were heavier than other hosts. The growth index of nymphs varied from ۰.۰۳۵ to ۰.۱۰۳, with the minimum on red cabbage and the maximum on cauliflower. The amylolytic activity in adults was higher on rapeseed (flower) and the lowest on red cabbage. In addition, the highest and lowest proteolytic activity was on rapeseed (flower) and red cabbage, respectively. The results of this study indicated that red cabbage was an unsuitable host for feeding of B. brassicae.

Brassica plants, digestive enzymes activity, life table parameters, plant resistance, the cabbage aphid