THE AIRPLANE IN CATALPA SPHINX CONTROL 127 



for two or three years without the presence of the caterpillars 

 being noticed, then, by reason of the fact that each mother moth is 

 capable of laying 300 eggs or more, a comparatively insignificant 

 number of the insects may serve as a basis for a brood of de- 

 structive proportions. 



This seems to have been the case in the grove of H. B. Carver 

 at Troy, Ohio, during the summer of 1921 when the insects ap- 

 peared in June in sufficient numbers to defoliate the entire plant- 

 ing. 



DESCRIPTION AND LIFE HISTORY OF THE CATALPA SPHINX 



The successive stages of the life history of the catalpa sphinx 

 are shown in the accompanying photographs. Fig. 6 shows the 

 gray moth resting on the trunk of a catalpa tree and demonstrates 

 the excellent protective resemblance which aids the insect in avoid- 

 ing its enemies. When the wings are expanded it measures about 

 three inches across from tip to tip. 



The eggs, Fig. 7, are deposited in masses on the underside of 

 catalpa leaves and are of a beautiful iridescent yellowish-green. 



Fig. 7. The eggs of the catalpa sphinx much enlarged 



The larva, Fig. 8, is of the usual horn-worm type, striped with 

 yellowish-green and black, and when mature measures about three 

 inches in length. 



The pupa, Fig. 5, is chocolate-brown in color and is found in an 

 earthen cell two or three inches beneath the surface of the soil. 



