REFERENCES 



Carthy, W. E. 1958. An introduction to the study of the behavior of invertebrates. 

 Macmillan, New York, 380 pp. 



Collins, F. D. 1954. The chemistry of vision. Biol. Revs. 29: 453-75. 



Elteringham, H. 1933. The senses of insects. Methuen & Co., London, 126 pp. 



Gross, A. O. 1913. The reactions of arthropods to monochromatic lights of equal 

 intensities. Jour. Exptl. Zool. L4: 467-514. 



Wolken, J. J. (Chrmm.) 1958. Photoreception. Ann. N. Y. Acad. Sci. 74: 161-406. 



Wulff, V. J. 1956. Physiology of the compound eye. Physiol. Rev. 36: 145-63. 



RELATION OF ENVIRONMENT TO PHOTOSENSITIVITY OF INSECTS 



[SUMMARY] 

 W. C. Cook 1 



A great deal of work has been done on the relation of environmental factors to 

 photosensitivity of insects, but much of this is purely observational and qualitative. Few 

 quantitative studies are available in which the various factors have been isolated and 

 studied. One of the best general studies is that of Stirrett (1938) 2 on the European corn 

 borer in Ontario, in which he compares his own studies with previous work. The factors 

 which he listed were temperature, humidity, wind, atmospheric pressure, rainstorms, 

 atmospheric electricity, cloudiness, lunar periodicity, fog or mist, and dew and guttation. 



TEMPERATURE. Anyone who has watched a light trap in operation has been im- 

 pressed by the irregularity of the captures. For a few seconds or minutes the insects will 

 literally come in clouds, and then stop as suddenly as they started. This will be repeated 

 again and again. The writer has exposed sensitive thermometers while watching such 

 catches, and had found that a change in temperature of 1° or 2° F. will cause this 

 fluctuation. A general cooling will be interrupted by a slightly -warmer breath of air for 

 a few minutes, and then followed by further cooling. Few thermographs respond fast 

 enough to catch these changes. 



Stirrett, in his review of temperature and flight, mentioned that most of those who 

 studied temperature found a positive correlation between flight and temperature. C. B. 

 Williams (1935) operated a light trap at Rothamsted, England, for several years, in 

 which a series of killing bottles made it possible to divide the night's catch into 8 time- 

 interval lots. He found the highest catches associated with nights having a high minimum 

 temperature and a flat temperature gradient from dusk to dawn. Poor catches were 

 associated with steeper temperature gradients. 



Dirks (1937), working in the cool climate of Maine, found very low catches at average 

 night temperatures of 40° to42°F., and his highest catches were at average temperatures 

 above 58° F. 



1 Entomologist, Entomology Research Division, Agricultural Research Service, U. S. D. A., Walla Walla, Wash. 



2 For references in this paper, see section on Bibliography of Insects and Light at end of this publication. 



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