84 ILLINOIS BIOLOGICAL MONOGRAPHS [402 



contiguous to concolorous suranal protuberances; suranal and subanal 

 lobes with numerous setae, which increase in length with the distance 

 from the anus; body yellowish green or brownish, with colored patches on 

 subspiracular and surpedal areas and on subdorsal line from mesothorax 

 to ninth abdominal segment; abdominal segments 2-8 on ventro-meson 

 each with a large colored patch; in younger stages body fuscous with 

 few distinctly delimited colored patches or none; M-1,-26,-50,-51,-48. 



Amauronematus Konow 



Larvae small to moderately large; length 15-20 mm.; body cylin- 

 drical, often tapering distinctly caudad; latus with subspiracular and 

 surpedal areas colored or with numerous, minute colored spots; head 

 blackish, brownish, or greenish; third abdominal segment with five annu- 

 lets, annulets 2 and 3 or 2 and 4 setiferous; tenth abdominal tergum with 

 or without caudal paired protuberances; body setae much longer or 

 shorter than the length of spiracles; larvapods with 2-3 or 3-5 setae as 

 viewed from side; spiracles not winged; larvae free leaf -feeders. 



The larval stages of five species of Amauronematus have been described 

 by Dyar. Of these, larvae of luteotergum, dyari, oregonensis, and similis 

 have not been available for study, but according to Dyar's descriptions, 

 the last three apparently lack the caudal paired protuberances. I have a 

 large number of larvae collected on willow by Dr. MacGillivray which 

 also lack the paired caudal protuberances and probably belong to this 

 genus. The species may be separated as follows : 



SPECIES OF AMAURONEMATUS 



1 (4) Tenth abdominal segment with paired caudal protuberances 2. 



2(3) Abdomen on ventro-meson with a row of blackish spots; caudal paired protuberances 

 and head blackish; gregarious; on alder luteotergum Norton. 



3(2) Abdomen on ventro-meson without a row of blackish spots; paired caudal protuber- 

 ances and head not blackish but pale; solitary; on Azalea azaleae Marlatt. 



4(1) Tenth abdominal segment without paired caudal protuberances 5. 



5(6) Mature and also younger larvae with antennae flattened and their segments fused 

 in part, with no discernible or with very small antacoria; younger larvae (14 mm. or 

 less) with annulets 1, 2 and 4 setiferous; annulets 2 and 4 with transverse row of 

 warty protuberances each bearing 2 or 3 stiff stout setae; older larvae (14 mm. or 

 more) without numerous brownish spots on dorsum and latus and without brownish 

 interrupted and diffuse dorso-mesal and dorso-lateral lines; on sweet fern; M-85. 



Amauronematus sp. 1. 



6(5) Mature larvae with antennae whose segments are all distinctly separated by distinct 

 antacoria; young larvae with antennae like those of preceding species; younger larvae 

 (14 mm. or less) with annulets 1, 2, and 4 setiferous; annulets 2 and 4 without 

 transverse row of warty protuberances the setae being minute and arranged singly; 

 older larvae (14 mm. or more) with numerous brownish spots on dorsum and latus 

 with brownish, interrupted, and diffuse dorso-mesal and dorso-lateral lines; on willow; 

 M-10 virendus MacGillivray. 



