340 



THE CANADIAN ENTOMOLOGIST. 



July 13 (about). — Second molt occurred (?) (Supposed, not 

 observed). 



July 24. — Entered the soil to pupate. 

 July 26. — Pupa formed. 

 Aug. 6. — Emergence of adult. 



Two other larvae which I collected the same season pupated 

 on July 15th and the adults emerged on the 25th. 



At the time of transformation of pupa to adult it is interest- 

 ing to observe how long it requires for the beetle to acquire its 

 normal black colour. At the time of transformation to adult the 

 thorax, head and legs are bright reddish brown. The rest of the 

 body is pure white. Gradually it becomes reddish brown, turning 

 to black. In about twenty-four hours after transformation the 

 beetle is perfectly coloured and ready to emerge. 



Description of larva. — First stage (fig. 29). The young larva 

 on leaving the egg-case is light brown in colour, later becoming 



dark velvety brown and measures 

 over 8 mm. in length, from the tip of 

 the abdomen to the tips of the ex- 

 tended maxillae. The head is large, 

 light brown in colour, somewhat de- 

 pressed and prominent, the mouth- 

 parts forming a very conspicuous 

 feature. It measures, exclusive of 

 the extended mouthparts, 2 mm. long 

 by 2.25 mm. wide, and appears very 

 large in proportion to the body, the thorax measuring less than 

 1.5 mm. wide. The antennae are prominent, each consisting of 

 three segments. The ocelli are six in number, placed in two 

 parallel rows at the side of the head, directly behind and below 

 the antennae. 



The body is densely clothed with dark hairs, giving the larva 

 a velvety appearance. Amongst the hairs may be found scattered 

 brown setae. The seven abdominal spiracles are prominent. On 

 the dorsal side of the last abdominal segment are openings leading 

 to the large longitudinal tracheal trunks which supply air to all 

 parts of the body. This pair of spiracles, with the two pairs on 





Fig. 29.- 



-H. triangularis, young larva 

 just hatched. 



