Show Spraying in Summer Will Not Halt Grubs Destroying Eggs Fails To Stop Winter inter A Attack AUak k Spraying cattle in fri summer with benzene rotenone or other insecticides new or old does not prevent grub infestation in win win- ter ten Although there is nothing new In that statement the need for tor repeating repeating repeat ing it is plainly indicated by an account of spraying dairy cattle in one of the corn belt states The work was given considerable publicity pub pub- with erroneous conclusions In this case older animals of tho the herd were sprayed with DDT Heifers Hellers Hell Hell- ers and calves were not sprayed because they were running in pas pas- lf S S S t d S i tj 4 1 Dipping method method is favored by some cattlemen to control grubs and other infestations ture Spraying them would have required getting them up and handling handling han ban dUng them The following winter it was noticeable that the cows which had been sprayed were not infected with grubs The young stuff was peppered with them The natural conclusion was that a 3 summer spray of DDT was effective That conclusion is unwarranted because as entomologists know older catt cattle catte e seldom if ever have grubs of the heel fly The young animals are the ones that suffer The department of agriculture says Many substances have been I applied to cattle to keep away heel hecl flys and to kill the eggs deposited on the legs of the animals All AU have been found to be either ineffective or impractical The best time for attacking the pest is when the grubs are in the backs of cattle |