Observations on the Influence of Temperature and Humidity on the Bionomics ofDysdercus cingulatus, Fabr.

Abstract

It is being recognized that for a satisfactory solution of many of the wider problems of Applied Entomology, a study of insect ecology is of paramount importance. It is expected that a knowledge of the factors which influence distribution and abundance of insects will arm economic entomologists better in their warfare against pests. Just recently, Lathrop (1923), Shelford (1927), Buxton (1929), Uvarov (1929), Gryse (1929), and others have shown the importance of meteorological phenomena affecting the development, distribution, and activities of insects. Although our knowledge of the two factors so far studied—temperature and humidity—is far from being complete, still the results so far obtained have proved to be of considerable value. Indeed, instances of the practical application of such knowledge are already available. From his studies on the effects of temperature on household insects, Howard (1896) has shown that cold storage provides an effective control of these pests. Pierce (1916) has correlated the relative advance and retreat of the fall army-worm, Laphygma frugiperda, S. & A., with changes in temperature. He maintains that a proper fixation of the zone of effective temperatures may make it possible to alter the sowing time of winter crops to avoid damage from this insect. Barber (1925) explains the decrease of the European corn-borer, Pyrausta nubilalis, Hübn., during certain years on the basis of adverse environmental conditions. A. Howard (1921), from his observations in India, states that there exists a definite relationship between termite activity and soil temperature.