INSECTS AND THE COLOR OF FLOWERS 



By Willard N. Clute. 



I 'HOSE who are interested in the pollination of flowers by 

 insects are often puzzled to account for the behavior of 

 their subjects, though doubtless much of their perplexity is due 

 to their attempts to reason out insect conduct according to rules 

 drawn from human conduct. If an insect happens to visit a 

 hidden flower which to the human sense of smell is odorless, we 

 at once wonder how the insect was attracted to it, quite forget- 

 ting that though odorless to us it may be filled with fragrance 

 so far as the insect is concerned. It is beginning to be pretty 

 well known that many flowers give off odors that our sluggish 

 sense of smell cannot perceive. Possibly all flowers are odorous 

 to the insects. 



Something akin to this also exists with regard to the sense 

 of sight. The human eye has a very limited range and per- 

 ceives only seven colors. Nobody knows what color the rays 

 below the red or beyond the violet end of the spectrum' are for 

 no human eye can translate these rays into color and yet the 

 insect eye may very likely be able to do so. Ants appear able 

 to see in ultra-violet light and from the fact that several flowers 

 have been discovered which reflect these rays it is probable 

 that other insects may perceive them also. 



Botanists often discuss the preferences of insects for 

 flowers of a certain color, but who knows whether the flowers 

 appear to insects as they do to us? As a matter of fact, they 

 probably do not. On this point an interesting light is shed by 

 a common wild sunflower {Helianthus lactiflorus) , shown in 



