OF WASHINGTON. 65 



Infested trees were quite common at the timber line on Mt. 

 Rainier, Washington altitude about 9,000 feet. On August 

 27, one pupa changed to an adult male; September 3, two 

 pupae changed to adult females; and on September 8 another 

 pupa changed to an adult male. 



The insect seems to do extensive damage to living trees by 

 entering small injuries and working into the surrounding 

 living tissues, thus causing wounds that remain open, and 

 enlarge instead of healing over. 



Adults have been taken in Texas, New Mexico, Canada 

 (Quebec), Nevada, California, Oregon, and Washington. 4 



The larva differs from all the other oedemerid larvae of 

 which descriptions or specimens could be found in the follow 

 ing grosser characters : In having no pair of ambulatorial pads 

 on the dorsal surface of the first thoracic segment ; in having 

 pairs of such pads on both the 4th and 5th abdominal seg 

 ments ; in having well developed abdominal feet, instead of 

 mere ambulatorial teats ; in having a pair of these feet on the 

 ventral surface of the 5th abdominal segment, a rudimentary 

 pair on the anterior ventral surface of the 9th abdominal 

 segment, and a pair of strong dark recurved hooks, with a 

 dark depression between, on the posterior surface of the 9th 

 abdominal segment. 



The larvae of the CEdemeridae illustrate very well the varia 

 tion in the ambulatorial pads and abdominal legs. As nearly 

 as could be determined from the descriptions read and speci 

 mens studied, GEdemera is the most generalized member of 

 the family and Calopus the most specialized. 



CEdemera larvae, descriptions of which the writer has seen, 

 have a pair of horny plates probably rudimentary ambula 

 torial pads on the dorsal surface of each of the dorsal seg 

 ments, and no abdominal legs. Larvae of Ditylus (descrip 

 tions seen), Nacerdes (descriptions seen and specimens 

 examined), and Xanthochroa (descriptions seen and speci 

 mens examined) have ambulatorial pads on the dorsal surface 

 of the ist, 2d, and 3d thoracic and ist and 2d abdominal 

 segments, and abdominal legs on the ventral surface of the 

 3d and 4th abdominal segments. Chrysanthia (descriptions 

 seen) has five pairs of dorsal ambulatorial pads and three 

 pairs of abdominal legs, one pair being on the ventral surface 

 of the 2d abdominal segment. Oxacis (specimen examined), 

 Probosca (specimen examined), and Asclera (specimen ex 

 amined) have six pairs of the ambulatorial pads, one being on 

 the dorsal surface of the 3d abdominal segment, and three 



a Vide Horn, Proc. Cal. Acad. Sci., 2d ser., Vol. vi, p. 385. 



