THE BEHAVIOR OF SOME SOIL INSECTS IN GRAD- 

 IENTS OF EVAPORATING POWER OF AIR, 

 CARBON DIOXIDE AND AMMONIA. 1 



CLYDE C. HAMILTON. 



PAGE. 

 I. Introduction 159 



II. Methods of Study and Material 159 



1. Methods of Study 159 



2. Material 164 



III. Experimental Results 165 



1. Larvae 165 



A . Controls 165 



B. Reactions in Evaporation and Temperature Gradients 166 



C. Reactions in Carbon-Dioxide Gradients 172 



2. Adults 173 



A . Controls ... 173 



B. Reactions in Evaporation and Temperature Gradients 173 



C. Reactions in Ammonia Gradients 176 



D. Reactions in Carbon-Dioxide Gradients 177 



IV. Summary and Discussion of Conclusions 177 



V. Acknowledgments and Bibliography 181 



I. INTRODUCTION. 



The study of experimental ecology has started only within 

 comparatively recent years and very little work has been done 

 upon the relation of evaporation to the life economy of animals. 

 The importance of the rate of evaporation as an environmental 

 factor has been discussed by Shelford ('14^, b, c). Since eva- 

 poration is determined by the rate of air movement, humidity, 

 temperature, pressure, and indirectly by illumination, it serves 

 as an index of the general weather conditions. By varying any 

 one of the factors controlling it, the rate of evaporation will be 

 changed. The purpose of this paper is to show the behavior of 

 some soil insects in evaporation, carbon dioxide, and ammonia 

 gradients under experimental conditions. 



II. METHOD OF STUDY AND MATERIAL. 

 i . Method of Study. 



The method and equipment used in establishing the evapora- 

 tion gradients was essentially the same as that described by 



1 Contribution from the Zoological Laboratory of the University of Illinois, No. 83. 



159 



