220 ENTOMOLOGICAL NEWS. [June, '06 



A New Sawfly. 

 BY T. D. A. COCKERELL. 



A nematid sawfly has attracted attention by its appearance 

 in the streets of Boulder this spring, being one of the earliest 

 insects on the wing. As it does not agree with any described 

 species, a description is offered : 



Pteronus arapahonum n. sp. 



cf. Length about 7 mm.; anterior wing 6-f. In Marlatt's table (Revis. 

 Nematinae, p. 44) it runs near to P. ribesii Scop., from which it differs in 

 the coloration of the thorax above, the mesothoracic plates being solid 

 black, the long third cubital cell, etc. Head and mesothorax shining 

 black, the latter minutely but distinctly punctured ; triangular mark be- 

 tween antennae, and broad anterior margin of clypeus (which is broadly 

 but shallowly emarginate) reddish yellow ; base of mandibles and labrum 

 (which is quite large) dull whitish yellow ; orbits dark, except a minute 

 reddish spot at the top of the eyes ; antennae feddish yellow beneath and 

 black above, the colors sharply contrasting ; joint 4 a little longer than 3; 

 scutellum except a large spot at base, postscutellum, lobes of pronotum, 

 and most of upper half of epimeron, reddish yellow ; lower half and more 

 of epimeron entirely black ; legs light reddish yellow, the coxoe, trochan- 

 ters and bases of femora yellowish white ; apex of hind tibiae, and their 

 tarsi, blackened ; wings hyaline (a little dusky), iridescent, the stigma 

 (which is very large and broad) and nervures black ; transverse costal 

 nervure only slightly oblique and about half as far below basal as basal is 

 before first cubital cell ; third cubital cell much longer than its apical 

 breadth ; second r. n. almost as far from base of third cubital cell as the 

 breadth of the base of latter ; upper discal cell of hind wings surpassing 

 lower at the point of junction ; abdomen reddish yellow, the two basal 

 segments more or less infuscated ; apical part of sheath black ; claws 

 strongly bifid, the teeth parallel and about equal. 



Var. a. Middle of scutellum infuscated ; light color on epimeron reduced 

 to a transverse mark ; third abdominal segment slightly infus- 

 cated in subdorsal region. 



Var. b. Transverse costal nervure only a short distance before basal. 

 Var. c. Third cubital cell much higher, especially at base. 



Hab. Boulder, Colorado, April 6th (T. D. A. Cockerell) ; 

 April 1 5th (W. P. Cockerell) ; April loth (S. A. Rohwer). 



THE REV. C. J. S. BETHUNE has been appointed professor of entomo- 

 logy at the Agricultural College at Guelph, Ontario, Canada, to which 

 place all communications should be sent. 



