Influence of some cruciferous plants on biological parameters of cabbage aphid Brevicoryne brassicae linnaeus (Homoptera: aphididae)

Investigation on biological parameters of cabbage aphid Brevicoryne brassicae L. on some cruciferous host plants indicated that it had to go through four nymphal instars to complete its developmental period on cabbage, cauliflower, mustard, rapeseed mustard, wild mustard and radish and five nymphal instars on knol khol and swine cress. The total developmental period with only four nymphal instars was longest on cabbage (8.73 d) and the shortest was found on mustard (8.02 d). However, the total developmental period increased in case of knol khol (8.92 d) and swine cress (8.75 d) due to fifth instar. The average reproductive period was longest on cauliflower (21.44 d) followed by cabbage (21.26 d) and the shortest was recorded on rapeseed mustard (17.28 d). The maximum fecundity was recorded on swine cress (74.55 nymphs/female), followed by cauliflower (72.08 nymphs/female) and the lowest was recorded on rapeseed mustard (48.72 nymphs/female) and mustard (49.99) and these did not differ significantly from each other. The adult longevity and total life cycle duration was significantly affected by the host plants. The longest average total life cycle duration was found on cabbage (31.97 d) followed by cauliflower (31.89 d) and the shortest was recorded on mustard (27.31 d) followed by rapeseed mustard (27.71 d). However the total life cycle duration was increased in case of knol khol (32.09 d) and swine cress (30.45) due to additional fifth instar.