Observations on the Life History and Control of the Cabbage Aphis, Bre Vicoryne Bbassicae L.

SUMMARY A study has been made ofthe life history of Brevicoryne brassicael. in the market‐garden areas of Bedfordshire, Cambridgeshire and Huntingdonshire from November 1933 to October 1935. There was a variation in the behaviour of this pest in the two years. In 1934 the aphis over‐wintered only as eggs on cultivated cruciferous crops (and particularly Brussels sprouts), whereas observations strongly suggest that in 1935 it over‐wintered both as viviparous females and eggs. The hatching of the eggs was much later in 1934 than in 1935, but the first winged forms were produced at about the same date. Predators and parasites were fairly abundant but not sufficiently so as to prevent serious damage. It is suggested that control measures should aim at preventing the aphides from passing from old plants to newly planted ones. Nicotine sprays or nicotine dusts are suitable for this purpose. The pest is difficult to control on ordinary field crops.