DESCRIPTION OF NEW INSECTS. 



By a. S. Packaed, Jr., M. D. 

 DIPTEROUS LAEVA POUND IN THE GIZZAKD OF PICOIDES ARCTICU3. 



Fig. 65, a, dorsal, h, ventral view of larva; c, end of body; d, side 

 view of end of body ; e, dorsal view of end of body ; /, bead, greatly 

 magnifiied. 



Body white, cylindrical, a little flattened, with twelve segments exclu- 

 sive of head, the segments moderately convex. Head very minute, 

 sunken in the small pro- p. , 



thoracic segment, (which ^^* 



is much smaller than the 

 second or mesothoracic T'j^ 

 segment;) subtriaugular z'''^-''^. 

 in form, a little longer j J 



than broad ; a transverse ^^-..— =— ' 

 suture just in front of in- 

 sertion of antennee indi- 

 cates the posterior edge 

 of the clypeus. Antennae 

 cylindrical, two-jointed, 

 the second joint longer 

 than basal, and rather 

 slenderer, its tip reaching 

 as far as the end of the 

 head. 



Terminal segment of the 

 body much smaller and 

 narrower than the penultimate, bearing two large, stout, upcurved 

 corneous hooks, with adjoining bases ; nine stigmata, one on prothorax 

 and one on first eight abdomiual segments, round minute, corneous, the 

 ninth round, with around area on one side. 



Length .35 inch; 135 specimens taken ''from the gizzard of Picoides 

 arcticus, (No. 236,) Lower Geyser Basin, August 26, 1872, by 0. H. 

 Merriam." Some of these larvcB were half grown. Most of them were 

 perfectly preserved ; a few had been partially digested. With them 

 were associated a part of the body of a Geramhycid larva, and a portion 

 of the elytra of a Scolytus-Iike beetle, so that they must have come fr^m 

 under the bark of some tree. 



This larva, remarkable for its large size, its minute head, and terminal 

 upcurved hooks, like those of many coleopterous larvae living under 

 bark, seems to be related to the young of the Cecidomyiadce, or iDerhaps a 

 closely allied group, from the two-jointed antennse, the general form of 

 the minute head, and the presence of nine stigmata. Several Cecidomyia 

 larvse have a pair of anal appendages, though not so marked as in the 

 present form. 



DIPTEROUS LARVA. 



