JOURNAL OF ANIMAL BEHAVIOR 



Vol. 1. MARCH-APRIL, 1911. No. 2. 



THE INFLUENCE OF DIFFERENT COLOR ENVIRON- 

 MENTS ON THE BEHAVIOR OF 

 CERTAIN ARTHROPODS 



By a. S. PEARSE 



Contributions from tlie Zoological Laboratory of the University of Michigan, Xo. ijo 



THREE FIGURES 



TABLE OF CONTENTS 



TAGE 



Introduction 79 



Description of Experiments 80 



The crayfish 80 



The spider crab 84 



(a) Black vs. white discrimination 85 



(b) Color discrimination 88 



The larva of the caddis-fly 90 



The crab-spider 92 



(a) Color changes 93 



(b) Reactions to flowers and colored backgrounds 95 



(c) Reactions toward bees and wasps 99 



Discussion of experiments 100 



The crayfish 100 



The caddis-fly larva: 102 



The spider-crab 102 



The crab-spider 103 



General considerations 105 



Coloration of arthropods 105 



Color discrimination 106 



Protective coloration 106 



Reactions in relation to color environment 107 



Adaptation ' 108 



Conclusion 109 



Bibliography 109 



INTRODUCTION 



The protective resemblances of various arthropods have long 

 been subjects of interest to naturalists, and a host of observa- 

 tions have been made which bear directly or indirectly on such 

 phenomena. There is no doul^t that many of these resemblances 



