6 BULLETIN 571, U. S. DEPARTMENT OF AGRICULTURE.- 



more susceptible to attack by certain wood-boring insects and less 

 able to withstand drought in summer. 



During the summer and early fall the larvae, then very small and 

 feeding but little, will be found attached to the underside of the 

 leaflets in brownish, minute, tortuous, and winding cases (PL I, fig. 5 ; 

 PI. Ill, fig. 2), which greatly resemble at a glance brown spots such 

 as might be caused by certain fungi. These tiny cases are enlarged 

 only as it becomes necessary for the larvae to build their way to new 

 feeding areas. A detailed description of the larval cases as they 

 appear during the summer and fall months is given on page 7. So 

 far as the writer has observed, the injury caused to the f oliage during 

 the fall is so slight that the leaves do not fall prematurely. 



DESCRIPTION. 



THE EGG. 



The egg is elliptical in outline, somewhat convex above and 

 flattened below. Viewed with the hand lens the surface is quite 

 smooth, but under higher magnification it is very faintly punctate. 

 When first deposited the egg is white with a slight greenish tinge, 

 translucent, and iridescent in some lights. The empty shell is white. 

 The average size of five eggs was found to be 0.55 by 0.33 mm. (0.0216 

 by 0.0129 inch). The eggs are deposited singly on the underside 

 of the leaflet and usually at the junction of the veins with the midrib. 

 Moths confined in rearing cages (battery jars) have been noticed 

 sometimes ovipositing upon the upper surface of the leaves, but in 

 no case has the writer observed such oviposition under natural 

 conditions. (PI. I, fig. 1.) 



THE LARVA. 



Upon hatching the larva is a little less than a millimeter (0.039 

 inch) in length. The head and prothoracic shield are brown in 

 color, while the rest of the body is of a much lighter shade of brown. 

 When extended the full-grown larva averages about 14.5 mm. 

 (0.5708 inch) in length by 2.0 mm. (0.0787 inch) in greatest width. 

 The head is round, shiny dark brown or blackish in color, and slightly 

 rugose. The general color of the body is very dark green, except 

 the prothoracic shield, which is somewhat lighter. The shape of 

 the larva is nearly cylindrical, tapering slightly at both ends, but 

 more posteriorly than anteriorly. The body is sparsely covered 

 with fine long hairs and on either side of the dorsal surface of the 

 second thoracic segment is a small well-defined tubercle, from the 

 black center of which arises a fine hair. The skin, especially in the 

 thoracic region, is quite wrinkled, there being a pair of crescentic 

 folds on the dorsum of the second and third segments. Rudiments 

 of these folds are evident on the other segments, but they are not 

 prominent. The first four pairs of prolegs are quite short, only 



