The Efficiency of Dormant Type Oils in Relation to Their Composition12

Abstract

A study is presented of the insecti-cidal efficiency of 39 petroleum oils of the dormant type using the fruit tree leafroller, Cacoecia argyrospila, as the principal test insect. Correlations between efficiency in controlling this insect and various properties related to the constitution of the oils were observed. Data on viscosity, viscosity index, unsulfonated residue, density, refractive index, specific refraction, specific dispersion and "Waterman analysis" are given for each oil. Evidence based on this data shows that an oil that is highly paraffinic in character and probably low in aromatic structures is the most desirable type for use in the control of the fruit tree leafroller. Theoretical and practical implications of the results of the study are discussed.