96 BULLETIN 417^ U. S. DEPARTMENT OF AGEICULTUEE. 



Generally the anal end of the beetle larva was seen protruding 

 through the meshes of the Hemileuca cocoon which indicated what 

 was happening inside. Upon closer examination it was found that 

 the Hemileuca pupa was being destroyed. These pupae attacked 

 were located 5 to 6 inches above ground, generally in Gutierrezia 

 plants, demonstrating the abiUty of the larvae to chmb for their prey. 

 Adults were also noted feeding upon the pupse to a small extent. 



BRIEF DESCRIPTION OF LARVA. 



First stage. — Long, rather slender larva. Average length of 5 newly hatched 

 specimens that had been preserved in alcohol, 10.3 mm.; width, 2.1 mm. In very- 

 young larvae head and thorax dull black and abdomen brownish-black above and 

 grayish-brown below. Ventral plates ordinarily containing from 1 to 3 long brown 

 hairs and sometimes other shorter ones. Caudal appendages long (2 mm.), straight, 

 projecting obliquely backward. 



Second stage. — Form similar to first stage. Average length of six fairly large speci- 

 mens, 19.6 mm.; width, 8.2 mm. Caudal appendages long, straight, bearing short, 

 acute protuberance dorsally in middle. Appendages continuing almost straight after 

 dorsal protuberance; Dorsum dull brownish-black, ventral plates brown. 



Third stage (PI. XVII, E). — Long slender larva. Average length of five almost 

 mature specimens, 31 mm.; width, 5 mm. Caudal appendages long (2 mm.), rather 

 slender, curving slightly backward up to short, acute dorsal protuberance located in 

 middle and straight beyond these. Color dull to shining black above, very dark 

 brown below. Ventral plates rather thickly clothed with short hairs. Anterior ven- 

 tral plates 2 to 7, inclusive, oval in form with slight dilations irregularly occurring in 

 middle of anterior margins. Anterior ventral plates also without median keel as 

 appears occasionally in obsoletum. Posterior median plates in well fed larvae with- 

 out broad line of separation between the two plates, apparently joined, especially 

 on 6th and 7th abdominal segments. Inner angles of all these plates square, outer 

 rounded, with outer margins containing broad deep notch in middle. Posterior 

 angles of anal segment short, obtuse, bearing spine at apex. Posterior angles of tergite 

 of penultimate segment also obtuse in form, almost truncate at apices. 



LARVAL RECORDS. 



Some feeding records were secured with larvse of this species by 

 Mr. Caffrey in August, 1913, at Koehler, N. Mex. At that time, 

 H. oliviae larvse which were offered were almost full-grown and in 

 most cases only a small number were required before maturity. Two 

 to three caterpillars were consumed in the first larval stage, 2 in the 

 second, and 4 to 6 in the third, or a total of about 10 to 12. The 

 beetle larvse were transferred from small containers for pupation 

 upon approaching maturity and the feeding record closed, otherwise 

 it is probable that slightly more would have been destroyed. These 

 beetle larvse were active and fed from about August 13 to August 26. 



The average time required to pass the first larval stage was 6 days ; 

 for the second 4.5, and for the third to date ceased feeding, 8. Addi- 

 tional to this, from 3 to 5 days are passed in the prepupal stage, thus 

 totaling 22 to 25 days in the larval stages to period of pupation. 

 The larva in the last few days of its activity makes an oblong-oval 

 cell in the earth for pupation, as is the habit with other species of 

 the genus. 



PUPA. 



Two rather undersized specimens reared at Koehler, N. Mex., 

 measured 17 and 15 mm. in length and 7.5 and 7 mm. in width, 

 respectively. These specimens were somewhat broken in shipment 

 to Melrose Highlands, Mass. The first five abdominal segments are 



