84 SMfTHSONIAN MISCELLANEOUS COLLECTIONS VOL. 82 



thoracic wings at first extend over the elytra. The pro- and meso- 

 thoracic legs are exposed, the metathoracic or hind legs are largely 

 hidden by the elytra and the hind wing's. None of the legs show 

 remainders of the sternal setae of the larva as was found by Hopkins 

 to be the case in Dendroctonus. 



All the setae of the thorax consist of rather fine hairs, the longest 

 of which are F2_4 of the pronotum. 



THE ABDOMEN 



The abdomen is that part of the body where the external changes 

 from larva to pupa are less pronounced. The united scutum and pre- 

 scutum, the pleuron and the sternum are defined by sutures or folds. 

 The pleuron is also subdivided into an epi- and hypopleurite. 



There are eight tergites well developed. Tergites one to seven are 

 similar in form. The outline is nearly regular rectangular. The first 

 five of them have the same number of setae as well as setae developed 

 in a similar manner. The setae ei_4 are arranged in a transverse 

 line near the caudal border of the tergites. The seta €2 is always 

 hornlike and enlarged with secondary hairs arising from it ; Ci is 

 always small and simple. 



The area around Co is strongly padded, raised, more steeply slop- 

 ing externo-laterally and gradually decreasing towards the setae e^ 

 and ei. In tergite six the setae e^ and e^ are of the same shape and 

 appearance as e2 in the foregoing tergites. The corresponding setae 

 of the seventh tergite are also more strongly developed than the 

 others but never reach the size and development of seta e2 in other 

 segments. The eighth tergite does not bear any setae. 



The prescutal area is not defined by sutures or lines but the setae 

 fi_2 are visible near the anterior border of tergites one to- seven 

 as minute hairs. They change neither in development nor in position 

 during the transformation from larva to pupa, but are completely 

 reduced on the eighth tergite. 



Pleurites. — The pleural area is, as in the larval stage, subdivided 

 into two subdivisions, the epipleurites and the hypopleurites. Between 

 them are situated the spiracles. The epi- and hypopleurites are nar- 

 row transverse bands, strongly padded and densely covered with 

 minute spines. The epipleurites one to seven inclusive are similar in 

 shape and bear, as in the larva, two small hairs each. The only dif- 

 ferences are in regard to their position. In the larva these setae are 

 diagonal to each other ; in the pupa, in a horizontal plane. The hypo- 

 pleurites are similar in shape and sculpture but bear only one hair 



