Biology of the cabbage whitefly, Aleyrodes proletella
Abstract: Historically the cabbage whitefly (Aleyrodes proletella) has been a minor pest of Brassica crops (Butler, 1938a), but recently it has become an increasing pest in Europe particularly of Brussels sprout and kale (Nebreda et al., 2005). The cause of this is not fully understood, but is believed to be due to a combination of factors. Knowledge about the biology of the cabbage whitefly is limited and most of what is currently understood about its ecology has been inferred from minimal anecdotal evidence. The overall aim of this project is to understand population trends of Aleyrodes proletella in the most vulnerable crops, Brussels sprout and kale. This includes understanding the key times of population/generation increase and colonisation of a new crop. This information can then be used to inform the development of an integrated control strategy using insecticides and other tools, which might include biological control agents and methods of cultural or physical control. Field populations of whitefly were surveyed on newly planted Brussels sprout and kale crops. Colonisation of the crop occurred before the emergence of the first generation adults on overwintering plants suggesting that overwintering females were the first to colonise, a fact that was not believed to be the case. Sampling will continue until early 2014. A commercial crop of oilseed rape was not found to support overwintering whitefly however this may have been caused by excessive damage by pigeons. Further surveys will be conducted in specialist areas of Brassica cultivation as these regions may support larger populations of whitefly.