Agricultural Entomology

Abstract

IN this book the author has restricted himself to the treatment of insect pests of the farm, to the exclusion of fruit insects. By way of introduction, Dr. Smith briefly discusses the current methods of insect control and their application to farm practice, namely, insecticidal or chemical, cultural, biological, and legislative. The relationship of insect outbreaks to weather conditions is illustrated by reference to several well-known species. For example, the diamond back moth becomes abundant in hot dry seasons and decreases in wet cold weather. The pale western cutworm (Porosagrotis orthogonia) is subject to similar fluctuations, but for an entirely different reason,which the author does not explain on p. 13. The prevalence of heavy rains in the months of May, June, and July constrains this North American species to abandon its subterranean workings and emerge on the surface, when it is then an easy prey to its parasites. The result is a decided diminution of its numbers the following year. So noticeable is the effect that a close study of the meteorological conditions is important in the forecasting of outbreaks of this species.

A Textbook of Agricultural Entomology.

By Dr. Kenneth M. Smith. Pp. xiii + 285. (Cambridge: At the University Press, 1931.) 12s. Qd. net.