New Combination Sprays for Codling Moth Control

Abstract

Lead arsenate is not an effective spray treatment for the second brood of the codling moth,Carpocapsa pomonella. From 40 to 50 per cent of worms placed on apples sprayed with lead arsenate 2-100 entered the fruit un poisoned. The addition of mineral oils of medium to high viscosity to lead arsenate greatly improved the insecticidal value of the lead arsenate. This combination spray has an ovicidal value of 80 to 95 per cent and a larvicidal value much greater than that of lead arsenate alone. Fish-oil is even more effective than mineral oils in, increasing the insecticidal value of lead arsenate. The nicotine-oil combinations have proved as effective as lead arsenate when applied in the cover sprays for the first brood and decidedly more effective if applied in the second brood sprays. All combination sprays of mineral oils with lead arsenate or nicotine sulfate are most effective if applied during the periods of maximum egg-laying. Because of cleaning difficulties, combinations of mineral or fish-oils with lead arsenate should be applied in first brood sprays and mineral oil-nicotine sulfate combination in second brood sprays.