52 BULLETIN 351, U. S. DEPARTMENT OF AGEICULTUEE. 



Second Molt of the Male. 



In 1912 the second molt was made by orchard larvae from the 

 thirty-eighth to the forty-third day, with its maximmn upon the 

 forty-first day, after emergence from the brood chamber. In 1913, 

 with a more favorable season, this molt was made by orchard larvae 

 upon the thirty-sixth day. Since the larvae entered the second instar 

 upon the eighteenth day, they averaged 18 days in the second instar. 

 Two rearings were made in 1913, the first from larvae that emerged 

 June 24 and the second from larvae that emerged June 26. The 

 former made their maximum daily molt for both sexes upon the 

 thirty-seventh day, the latter upon the thirty-fourth day. 



When the male larva shrinks at the end of the second instar the 

 larval skin retains its original shape and position (PI. II, 6). This 

 leaves the larva nearly free within. At this time a decided meta- 

 morphosis begins. The original legs, antennae, and mouth-parts dis- 

 appear and the anal lobes, which in the second instar are one-half as 

 wide as the body and extend caudad beyond the anal plates (PL II, a), 

 now shrink to short, narrow projections which extend only slightly 

 beyond the anal plates. As a result of this change in the anal 

 lobes the anal crease disappears and the anal apparatus assumes 

 again its original position on the caudal margin. During this meta- 

 morphosis the hard portions of the mouth-parts remain attached to 

 the larval skin and disappear at the second molt, after which all trace 

 of the mouth-parts is lost. In the act of molting the larval skin is 

 ruptured by contortions of the larva along the middorsal line, and in 

 a few minutes it is worked downward and backward and is expelled 

 at the caudad margin of the puparium, where it usually remains for 

 a few days clamped under the puparium. 



The Prepupa. 



The prepupal instar is characterized by a rapid metamorphosis, 

 which, however, actually starts before the casting of the second molt 

 skin. The plump anal lobes of the first and second instars shrink, 

 and the characteristic anal plates (PL II, a) are lacking. The most 

 evident characters at the beginning of the instar are the wing-pads 

 and the pointed anal lobes. 



The prepupal period covers but 2 days, yet the metamorphosis is 

 so rapid that decided changes occur. The wing-pads expand to their 

 full size; the antennal sheaths expand from buds to nearly one-half 

 of their final length, and the leg sheaths, which at the beginning of 

 the instar were indicated by imaginal buds, become one-fourth devel- 

 oped. The metamorphosis of the anal region continues throughout 

 this instar and at its end all trace of the conspicuous anal plates is 

 lost. In their place there now project from the caudal extremity two 



