24 BULLETIN 417, U. S. DEPARTMENT OF AGRICULTURE. 



Third stage. — Form robust. Length of one alcoholic specimen, 20.5 mm.; width, 

 6.5 mm. Caudal appendages long, slender, spreading widely apart at tips. Protuber- 

 ance short, acute, making angle of 45° with appendage, and located slightly more than 

 one-half distance from base to tip. Tergites not protruding as far laterad in partially 

 fed larvae as in second stage. Color dull black on dorsum, ventral plates dark brown 

 to grayish brown. No reddish-brown patch at base of caudal appendages in second 

 and third stages. 



TIME REQUIRED TO COMPLETE LARVAL STAGES. 



The time required to pass through the differ ent larval stages was only- 

 secured with the first two, as all larvae failed to live through the third 

 stage. Three larvae hatched June 24, 1912, and died July 6, 9, and 

 11, while in the third stage. Two of these larvae molted to second 

 stage on the third day after hatching and one on the fourth. Three 

 to five days were required to pass the second stage and the larvae all 

 died after 7 and 8 days in the third. An average of these records 

 indicates that 3 days are required to complete the first and 4 days the 

 second stage. 



No pupal records could be obtained, as the larvae died in the third 

 stage. 



FOOD CONSUMED BY LARVAE. 



So few larvae were secured during the series of years these experi- 

 ments were conducted and so many specimens died that the feeding 

 records are far from complete. Two larvae, all that hatched in 1909, 

 were fed until both died while in the second stage. The first hatched 

 July 6 and died July 13, consuming in the meantime five sixth-stage 

 caterpillars of Porthetria dispar. The second hatched July 13, con- 

 sumed three sixth-stage caterpillars of Porthetria dispar and was 

 found dead July 23. 



Records were kept of 12 larvae that hatched during 1912; most of 

 them died in the first stage but a few lived to reach the second and 

 third. One larva consumed nine fourth-stage caterpillars of Porthetria 

 dispar and another destroyed nine pupae of the same species and died 

 in the third stage. 



The records at hand are so incomplete that a definite statement can 

 not be given of the amount of food required by the larvae. The adults 

 are somewhat larger than those of C. lugubre, and it is probable that 

 they require about the same number of medium-sized caterpillars or 

 pupae for the completion of their growth, or an average of 21. The 

 feeding period probably extends over about 20 to 25 days. 



HABITS OF LARVAE. 



During the season of 1912 some notes on the climbing habits of 

 the larvae were obtained. (PL III.) 



June 24 two newly hatched larvae were placed in the experiment. 

 Many observations were made on these during the time they remained 

 in the first stage and they made no attempt to climb. When placed 

 upon the bark they would immediately crawl and wedge themselves 

 under the nearest loose scales, and remain there for hours unless 

 disturbed. In attempting to crawl they usually fell to the ground. 

 The second-stage larvae maneuvered in about the same manner when 

 placed upon the bark of the tree. One crawled back and forth on a 

 limb but when it attempted to climb up or down the trunk it immedi- 

 ate! v fell. 



