192 OHIO EXPERIMENT STATION: BULLETIN 194 



mass to cast their skins and after the completion of the operation 

 pass back along their well marked trail to their feeding grounds. 

 A considerable quantity of the cast skins remains attached to the 

 tree at the point where the cluster of larvae rested. They again 

 travel en masse when they pass to the ground to pupate. 



The insects may be destroyed in great quantity while they are 

 settled upon the trunk of the tree during their molting period, or 

 the crop of insects for the following season may be considerably les- 

 sened by thoroughly working the ground beneath the tree during 

 the winter months to destroy the hibernating pupae. 



~ . . This insect has been known to occur in 



1 he Catalfia iSp/mix, ~. . P e Tl . 



Ceratomia catalpa Ko\*. Ohio for a number of years. It is only 



since the catalpa has become so popular 



as a tree for forestry purposes that the catalpa sphinx has attracted 

 very much attention. Its ravages are confined mainly to the south- 

 ern part of the state. 



The insect, as represented in the different stages of its develop- 

 ment by Plate 12, is most easily detected by its work upon the leaves 

 during the larval stage. The tiny worms may be observed feeding 

 in rows or clusters upon the epidermis of the leaf. Later the whole 

 leaf is eaten and in case of bad attacks the entire tree is defoliated, 

 as represented in Plate 13, Fig. 1. The larva is first of a pale 

 yellowish-green color and bears a black horn or spine at the rear of 

 the body. When full grown it resembles the large green tomato or 

 tobacco worm, with the exception that the color, instead of being 

 solid green, is green with broken black bands extending lengthwise 

 of the body. The worms may be observed in Ohio at least twice 

 each season once in June and again in late summer. Possibly there 

 are more than two broods. 



The larva pupate under the surface of the soil, the pupa proper 

 being reddish brown, and somewhat smaller than that of the tobacco 

 sphinx. It also lacks the peculiar "jug handle" common to the 

 other species. 



The moth is of the regular sphinx type; pointed body, narrow, 

 strong wings, large eyes, and is of a gray ashy color. The eggs 

 are deposited in pearly masses on the under sides of the leaves. The 

 winter is passed in the pupal stage. v_ 



Three methods of control are practicable to be used against the 

 pest. The first is collecting the egg-masses or clusters of newly 

 hatched larvae. The second method is spraying with arsenicals. 

 The third, recommended in Bui. 7, Ohio Department of Agriculture, 

 Division of Nursery and Orchard Inspection, relates to the control 

 of the species in nurseries or plantations and consists in deep plow- 

 ing at the time the insects are in the pupal stage. 



