Results of a 1962 field trial for the chemical control of grass grub (Costelytra zealandica (Wh.), melolonthinae, scarabaeidae.)

摘要

Abstract In a trial laid down in 1962 against the common grass grub (Costelytra zealandica (Wh.)), 2 lb DDT per acre in the form of dry mix DDT/superphosphate, granular DDT/superphosphate, DDT prills, DDT clay granules, and DDT wettable powder sprayed, all unexpectedly failed to give effective control. Laboratory examination of larvae from the area indicates that a degree of tolerance to DDT exists. Diazinon applied at 4 and 2 lb per acre, azinphos ethyl at 4 lb and heptachlor at 2 Ib all gave excellent initial results. Azinphos ethyl applied at 2 lb per acre and DC 10854 at 2 Ib per acre were intermediate in effect. Results were assessed by reduction in grass grub numbers and by pasture response. A high negative correlation was found between the two.