CATERPILLAR PEST

Evening Post, Volume CXV, Issue 77, 1 April 1933, Page 12

CATERPILLAR PEST

A DIFFICULT PROBLEM

. The unusual destructiveiiess of. cater* pillars among the lupins this year -wag recently brought under the notice.of th« Minister of Agriculture (the Hon. C. Et ■Waemillan) by. Mr, W. H. Field, MJV and the Minister has now supplied. Mr. Field with a report by the Department* entomologist. He writes:— . ' . "I regret to say that I do not know of any suitable method of controlling th« caterpillars referred to except by the us« of lead arsenate sprays, which method, of course, would appear to.be inipractic* able, on a field scale., Mecyna maoialis is, of course, parasitised by the Ichneumon Ecthromorpha intricatoria, and it seems riot improbable that the present outbreak may be just one of those periodic, disturbances so frequent in the insect world, due partly to favourable 'climatic conditions and partly to the temporary failure of the natural biological controlling factors. This, of course, is merely an opinion, and may not be justified by subsequent events. It woiild^ appear that tha situation needs careful watching,' and 'should, the insect during the next-season or two maintain its present attacks on the lupins the matter should be more thoroughly investigated with the object of evolving suitable control methods. Tha genus is world-wide, and it might be possible after suitable investigations to find parasites that might hold this, insect. in check: ■ ' ' .' ' '' ,■■''■ "Quito a deal of information line been sought regarding'M. maoralis during th« past few months; and Mr. Field's account of its attack on lupin is the second com* plaint of serious damage to this plant.,Thi other crime from the inspector of stock at Wanganui,, .where: it was stated that th« caterpillars were taken from lupins ad« jacent to the line near Maxwell railwaf station. They were reported as stripping all the lupins around that locality, in* eluding those-on the sandhills. , Everf vestige of foliage was taken, and also th# \>ark." -■■■■■' '■- '■■' ■' . '