Two recently identified compounds ("CIFs"), present on the leaf surface of
Brassica oleracea (cabbage), are the strongest oviposition stimulants known
for the cabbage root fly, Delia radicum. Cabbage leaves contain these comp
ounds in extremely low concentrations, and the amount of CIFs obtained from
purifying leaf extracts was so small that it limited further research. We
were able to purify far more of these two compounds from the roots of Brass
ica napus var. napobrassica (rutabaga). Apart from being a richer source of
CIFs, rutabaga roots are considerably easier to collect and process than l
eaves. In addition, we isolated and identified a new CIF compound from the
roots that is also very active in stimulating oviposition in the cabbage ro
ot fly.