STUDIES ON THE BIONOMICS AND CONTROL OF THE BURSATE NEMATODES OF HORSES AND SHEEP: VII. THE EFFECT OF SOME SUBSTANCES, USED IN THE CONTROL OF FARM AND HOUSEHOLD PESTS, ON THE FREE-LIVING STAGES OF SCLEROSTOMES

Abstract

The effect on the free-living stages of Sclerostomes caused by the addition to fresh horse faeces of some substances used in the control of household and farm pests, is discussed. Under the conditions of these experiments para- and orthodichlorbenzene will sterilize about 400 times their weight of faeces. Sodium fluoride will sterilize, on an average, approximately 150 times its weight of faeces, but it is almost twice as effective if applied as a very weak solution. Sodium silicofluoride, which also is most effective as a very weak solution, probably has an approximately equal value. Naphthalene, when mixed in the faeces, will sterilize about 270 times its own weight. Dichloropentanes will sterilize about 185 times their weight of faeces. 40% nicotine sulphate will, on an average, sterilize approximately 14 times its weight of faeces, but as a weak solution may be five or six times as effective. Ethylenedichloride, chloroform and carbon tetrachloride will sterilize about 21, 18 and 12 times their weight of faeces respectively. Trisodium phosphate will sterilize only about eight times its weight of faeces. Tobacco dust will probably sterilize slightly over twice its weight of faeces, but pyrethrum powder, derris powder and white hellebore powder have no lethal value. Ferric oxide and carbon monoxide also are useless.