Performance of the Cabbage Aphid 'Brevicoryne brassicae' (Hemiptera: Aphididae) on Canola Varieties

The cabbage aphid 'Brevicoryne brassicae' L. (Hemiptera: Aphididae) is one of the most abundant canola pest insects, causing economic damage to flowering and podding crops. Cabbage aphid performance (abundance, fecundity, development, longevity and generation time) in canola, juncea canola, and canola-mustard was studied under glasshouse conditions. The three canola varieties tested in this study are highly susceptible to cabbage aphid damage. There were no significant differences between canola-mustards and conventional canola in attracting cabbage aphids. Twenty one days after the initial aphid infestation, numbers of winged adults and wingless adults were similar among the canola varieties (p>0.05). Within a 'Brassica' variety, cabbage aphids responded differently to plant parts. In the life table study, there was a significant difference in fecundity (p=0.04), finite rate of increase λ (p=0.048) and doubling time DT (p=0.032) of cabbage aphids reared on mature leaves among the canola varieties. The highest fecundity (55.93 ± 3.35 nymphs/female) and intrinsic rate of increase rm (0.364 ± 0.013) were observed on canola-mustard. However, no significant differences were found in the nymphal development period, longevity, survival and mean generation time of cabbage aphids on the canola varieties tested. Assessing the ability of mustard and canola varieties to resist aphid infestation in the drier and warmer regions of Australia is critical with new canola varieties being released, and the increasing climatic variability in the cropping regions of NSW due to human-induced climate change.