THE COLOR VISION OF INSECTS 



Timothy H. Goldsmith i 



The Biological Laboratories 



Hamard University 



Cambridge, Massachusetts 



Insects, as a group, have been very successful. Approximately four 

 out of every five species of animals belong to this class, and in a 

 significant sense this is the age of insects. Yet the sensory apparatus 

 of insects is not at all well understood. 



This review treats but one aspect of vision in insects — the dis- 

 crimination of wavelengths. Even this problem, however, reaches 

 into opposite corners of biology. We should like to know how, in 

 terms of molecular and neurophysiological mechanisms, the visual 

 systems of insects operate. But it is also important to ask why, in 

 terms of animal behavior and evolutionary history, particular sensory 

 systems exist. If in the following pages the first of these general 

 problems appears to receive undue emphasis, it is only because the 

 answers we have here seem somewhat less speculative. 



The Presence of Color Vision in Insects 



There is evidence for color vision in six of the approximately two 

 dozen orders of insects that are recognized (Table 1). This statement 

 does not mean that only a few insects have color vision; it indicates 

 a dearth of comparative data. In fact, the capacity to distinguish 

 colors may well have developed early in the evolution of insects, for 

 both paleopterous and neopterous species are represented in Table 1. 



The evidence for color vision is derived principally from three 

 sources. Certain insects can be trained to associate food with colored 



' The author is a member of the Society of Fellows of Harvard University. 

 Present address: Department of Biophysics, University College, London; after June, 

 1961, Department of Zoology, Yale University, New Haven, Conn. The experiments 

 of the author were supported in part by a grant (B2077 (A)) from the Institute 

 of Neurological Diseases and Blindness, United States Public Health Service. 



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