60 ILLINOIS BIOLOGICAL MONOGRAPHS [378 



tapering to distal end, distal segment microscopic, mamma-like, without 

 tarsal claw; larvapods vestigial, located on abdominal segments 2-8 and 10, 

 anal larvapods united on the meson, forming a single sucker-like pro- 

 tuberance; head distinctly depressed, pointed, sub triangular in contour, 

 partly overlapped by protruding pro thorax; mouth directed cephalad; 

 vertical furrows obsolete; antennae with 3-4 segments, segments 1 and 2 

 large and conical, segments 3 and 4 subcylindrical and much smaller and 

 less in diameter than proximal segments; mouth-parts modified, mandibles 

 slender, sharply pointed, without dentes, blade-like; labium flattened and 

 large; spiracles not winged; ventral and prothoracic glands wanting; 

 glandubae obsolete; body not slimy; leaf-miners. 



Phlebatrophia MacGillivray 



Larvae very small, whitish; length less than 10 mm.; body distinctly 

 depressed, tapering much caudad, broadest on mesothorax, prothorax 

 declivous cephalad; lateral lobes somewhat prominent; tenth abdom- 

 inal tergum convex, almost glabrous, about half as wide as mesothorax; 

 suranal and subanal lobes semiglabrous; third abdominal segment with 

 two annulets, caudal annulet about four times as long as the cephalic, 

 microscopically and sparsely setiferous; thoracic legs fleshy, tarsal claws 

 wanting; larvapods rudimentary; ocularia protruding, located laterad 

 of antennariae; epicranial suture in part obsolete; spiracles not winged; 

 spiracular line normal in position; maxillary palpi with four segments, 

 labial palpi with two segments; totaglossa roundly protruding; stipes 

 elongate, subgalea long, slender, with distinct chitinized carinae; labrum 

 flattened; mandibles slender, sharply pointed, without dentes, blade-like; 

 leaf-miners. 



Phlebatrophia mathesoni MacGillivray. — Length, 7 mm. ; width of head, 

 1 mm.; mesothorax, 2.4 mm. wide; head light brown, mandibles and 

 carinae of subgalae deep brown; maxillary palpi typically 2, 1, 3, 4, distal 

 segment very minute; antennae with proximal segment or segments 

 larger in diameter and fleshy, conical, two distal segments together smaller 

 and shorter than the other two segments, but longer than labial palpi; 

 distal segment of labial palpus very minute; leaf-miners of birch; C and G. 



Subfamily Tenthredininae 



Larvae (Fig. 13) of medium to rather large size; body cylindrical, 

 slender, tapering uniformly and gradually caudad; segmentation and 

 annulation distinct, fine; third abdominal segment with seven annulets, 

 annulets 1, 3, and 5 setiferous and 3 and 5 with transverse row of glandu- 

 bae; abdominal segments 2-8 and 10 with larvapods; antennae with five 

 segments, slender, cylindro-conical; body uniformly greenish, with dark 



