COLOR AND THE BEHAVIOR OF ARTHROPODS 



93 



TABLE VI 



Showing the Total Number and the Colors of Spiders Collected with a 

 Beating Net from White and Yellow Flowers 



{Linaria vulgaris) ; white— boneset (Eupatorimn perfoliatum) , 

 domestic buckwheat (Fagopyruni esculentum), and a few from 

 milfoil (Achillea Millefolium). Table VI shows clearly that a 

 majority of white or yellow spiders are found on the corres- 

 pondingly colored flowers.* 



Having determined that Misumenas usually correspond in 

 color to the flowers in which they lurk to capture their prey, 

 attention was next directed to the causes determining this corres- 

 pondence. In this connection three possible explanations were 

 tested to some extent: (i) color changes, (2) positive reactions 

 toward certain colors or flowers, (3) the elimination of individuals 

 not matching their color backgrounds by predaceous enemies. 



(a) Color changes. Efforts were made to induce Misumenas 

 to change from white to yellowy or from yellow to white, by 

 keeping them on white or yellow backgrounds. 



Experiment 1. Spiders were placed in covered glass dishes 

 surrounded on all sides but the top by colored paper. The 

 colors were the same as those used in the experiments with 

 Libinia (p. 89). On August 20, 1909, one white spider was 



* Although collections were not very extensive from flowers other than yellow 

 and Avhite, the following results show that the majority of spiders were white. 



Color of spider White Yellow Green Red 



Epilohium angustijolium — purple 10 



Eupatorium purpureum — purple 30 3 1 



Polygonium sp.? — pink 1 1 



Aster laevis — blue 10 2 



Erigeron annuus — yellow and white 4 1 6 



Total 55 5 8 



Per cent 81 7 12 o 



