26 Journal New York Entomological Society. [VoI. vi i. 



ON THE LARViE OF ATOMACERA AND SOME 

 OTHER SAW-FLIES. 



B\ Harrison (r. Dvar. 



Atomacera* desmodii, sp. nov. 



Male agrees with Say's description of A. i/c/'///s, but is smaller, 

 length 2 mm. or less. Four submarginal cells are present : the third 

 joint of antenna; does not taper to tip, but is somewhat thickened on 

 its basal fourth. 



Female agrees with Norton's description of .4. nificollis, but the 

 thorax above is wholly yellow red, without any black s])ot and the 

 third joint of antenna is more thickened. Length 4 mm. Closely 

 allied to A. nificollis Xort., but the third submarginal cell has its bor- 

 dering veins parallel, while in nificollis they are divergent. Larva, 

 last three stages observed. 



Stage. — Head .6 mm. As in the next, translucent yellow, the tood 

 green, shining ; spinous tubes black walled. 



Pcniiltimafc sArgt'. — Head .<S mm., pale brown, eyes black. Body 

 as in the last stage, but more yellowish, yellow except for the green 

 food, the tubercles only very faintly shaded ; nothing conspicuous but 

 the black-walled tubes in twelve transverse rows which make the larva 

 look shortly spiny. Thoracic feet stumpy, thorax a little widened. 



Zast s/tig('. — Head round, brownish green, shining, ocellus in a 

 black spot ; antenna; rudimentary ; width i mm. Body somewhat 

 flattened, the subventral region protruding, fluted ; feet on joints 6 to 

 12 and 13, rather slender. Segments with four rounded areas on each 

 side like short tubes on the posterior third of the segment, subdorsal, 

 lateral, stigmatal (posterior) and subventral. These tubes are hollow, 

 colorless, dusky edged, erect, and from the top of each a round drop 

 exudes when the larva is irritated. Before the subdorsal tube on an- 

 nulet I is a tubercle with a seta; another on annulet 2, also before 

 the tube, consisting of two tubercles conjoined or separate; below 

 the subdorsal tube and touching it a large tubercle with one seta ; the 

 stigmatal tube arises from the upper edge of a large tubercle with one 



* Mr. Aslimead's genvis il//i;7'(i:/-^t' is a synonym oi Aloinacera. His statement 

 that the third joint of antenna; is furcate is an error, as no male of ./. ruficoUis is 

 known. A. dcbilis Say is probably the male. 



