An Analysis of Insect Environments and Response

Abstract

It has become increasingly evident of late years that a detailed study of the environment is of first importance in dealing with control measures for injurious insects. All forms of life are most intimately related to their respective environments, being so nicely adjusted to them that any considerable change in the conditions exerts a very marked influence either in favor of the organism or to its detriment. The organism is, in other words, what its environment makes it. Thus, if we know accurately the conditions of its environment, we know how to change the whole economy of the organism by perverting certain of the controlling conditions. It is axiomatic that the best method of control in the case of a given insect is to substitute for its normal environment an inimical one. Moreover, during its life cycle, the insect is subjected in most cases to several distinct environments, and it is important to know which one of these may be most profitably manipulated for its destruction. It is clear that the study of environments will be the first and last steps toward control in the entomological work of the future. But the question has always been how to approach and encompass this subject, how to determine accurately the influence of all the various conditions on the particular insect under consideration. Everyone realizes that the whole life cycle and economy of the insect, its habits, its physiological and structural characters, are the result of the environmental conditions which constantly surround and affect it. But how to get an accurate and tangible expression of these conditions for practical use is a matter that has long been the subject of earnest investigation in both Europe and America. The writer has for very many years, and especially during the past fifteen years, attempted to elucidate the study of insect environment, and reduce it to a comprehensive, tangible, and workable form. Only within the past year or two has he succeeded in securing results which partially satisfy him in this regard. The purpose of this paper is to present briefly these results. Early in his work, the writer perceived that environment students were constantly confusing various elements of the environment. It seemed to be commonly accepted that the environment consisted entirely of factors, or forces acting on the organism, and that factors and responses constituted the whole subject. In reality, the environment consists of several classes of elements, as is demonstrated by a thorough analysis of it; and, if all these elements be indiscriminately interpreted as factors, it is impossible to get a clear idea of environmental functions.