Tobacco Dust as a Contact Insecticide

Abstract

From the data secured during experimental work reported on the following pages, it is concluded that the finer grades of tobacco dust, containing 1 percent nicotine, are highly toxic to the spirea aphis (Myzus persica) . Observations of the spirea plantings under treatment during the past two seasons also indicate that timely applications of fine tobacco dust would afford adequate protection. In comparison with superfine tobacco, dust mixtures containing free nicotine or nicotine sulfate were, on an average, somewhat more effective but the actual difference in toxicity was not marked. As the tests were made in greenhouses it is not safe to conclude that finely powdered tobacco would prove equally effective against the same insect under normal field conditions. The insecticidal properties, however, are such as to suggest the desirability of more knowledge of the value and economy of the material in combating other noxious species. In conclusion it should be noted that commercial grades of tobacco show a lack of standardization since they vary greatly in nicotine content and physical properties. Considering the nicotine content of tobacco dust and commercial brands of tobacco extracts in relation to prices, powdered tobacco is apparently more expensive than the commercial solutions.