NOTES ON SOME SAWFLY LARVAE BELONGING TO THE 

 GENUS DIMORPHOPTERYX. 



By William Middleton. 



Of the Bureau of Entomology, United States Department of Agriculture. 



The following account, which is a contribution from the Branch 

 of Forests Insects, Bureau of Entomology, deals with the known 

 larvae of the sawnies belonging to the genus Dimorphopteryx, and has 

 been prepared under the writer's direction by Mr. Middleton, who 

 was assigned to assist in the rearing of Forest Hymenoptera. It 

 has been Mr. Middleton' s duty to make notes and care for the rear- 

 ing material of the species of this genus, and for this reason he has 

 been requested to work over the notes available and prepare them for 

 publication to follow a synopsis of the adults. Special attention has 

 been paid to the specific differences in the larvae at hand, to add 

 additional proof as to the validity of the species founded on adult 

 characters. Brief statements describing the type of work, the time 

 of appearance of the larvae, and methods of pupation have been 

 added, to aid collectors and to convey an idea of the seasonal history 

 of these insects. — 8. A. RoTiwer. 



GENUS DIMORPHOPTERYX. 



Characters of immature stages common to species studied. 



Egg. — The egg of one species has been described by Doctor Dyar, 

 and the egg-laying habits of the other species are no doubt similar. 



"[Eggs deposited] under the upper epidermis [of leaf] in an irregularly elliptical 

 area [approximately] 1.7 mm. by 1.4 mm., transparent, overlaid by the reticulations 

 of the epidermal cells. Before hatching the larva swells up somewhat and a ring of 

 air forms around it, appearing like a white margin." Dyar, Journ. N. Y. Ent. Soc, 

 vol. 5, 1897, p. 199. 



The following characters of the larva, prepupa, and cocoon are 

 common to all of the species studied. 



Larva. — Shape sluglike, not slimy; many distinct annulations; 

 skin dull, finely granular. Head higher (dorsad-ventrad) than 

 broad; eyes in dark spots; antennae 5-jointed. Thorax: The 

 lateral or pleural folds lobed and tuberculate; legs 4-jointed, the 

 fourth joint modified into a claw. Abdomen: Intermediate segments 



Proceedings U. S. National Museum, Vol. 48-No. 2083. 

 59758°— Proc.N.M.vol.48— 14 32 497 



