WHITE BUTTERFLY PARASITE

Press, Volume LXXIII, Issue 22142, 12 July 1937, Page 7

WHITE BUTTERFLY PARASITE

to rn« soitob or the pbess Sir,—Some days ago there appeared in "The Press" a small paragraph concerning the white butterfly parasite. In it Mr J. W. Muggeridge, Government Entomologist, is credited with saying that rape and turnip crops could not be grown in New Zealand now were it not for the help of this parasite. No one so far has questioned this statement, which is contrary to what we were led to believe when the white butterfly first made its appearance in New Zealand. A prominent entomologist in Canterbury, who has had considerable experience with it in Great Birtain predicted that the butterfly would not become a serious menace to those twp members of the cabbage tribe, though he expected the cabbage and cauliflower crops to suffer heavily; and I think events have proved him right. The diamond-back moth has been, and is, a far greater pest than the butterfly is likely to become, with or without parasites, and it shows some weakness in the organisation of research work that the spectacular n wcomer should be given such prominence, while the very real and oldestablished problem of the tiny moth should receive so little attention. Even when the butterfly was making its first appearance in small numbers many farmers attributed to it the great damage which all the time was being done to turnips and rape by myriads of the tiny culprits. No doubt the white butterfly is bad enough in its special lines, but cabbages and cauliflowers, and even chou moellier form only a small part of the 600,000 acres quoted in the paragraph. Another destructive pest in Canterbury farming, especially in the freer soils, is the grass grub, which, like the little moth, gets little attention. Surely in research organisation pood generalship is needed to sort out the problems which merit first attention, though scientists themselves do not seem quite agreed that the order of importance should be that which promises best results; that is, financial results. Incidentally, the term research is now given a much wider meaning than v hen it implied trying to discover something new, and much detail work which requires skill and care comes under the heading of research to-day.—Yours, etc., T A S. July 10, 1937.