403] LARVAE OF THE TENTHREDINOIDEA—YUASA 85 



Another species, resembling the preceding very closely and, difficult to distinguish except 

 by the colored spots which are more or less darker and shghtly more numerous than in 

 virendtts: M-112 vescus MacGillivray. 



Pteronidea Rohwer 



Larvae small to moderately large; length 15-25 mm.; greenish, often 

 spotted or banded transversely or longitudinally; body cylindrical, slender, 

 uniformly tapering caudad, thorax rarely conspicuously swollen; head and 

 trunk setiferous, often tuberculate; head blackish, brownish, or greenish; 

 antennae with four segments, sometimes with segments in part fused, 

 conical, subconical, or flattened; third abdominal segment with 4-6 

 annulets, more commonly 5-6, annulets 2 and 4, rarely 1, 2, and 3 setiferous; 

 tenth abdominal tergum with or without a pair of small but distinct suranal 

 caudal protuberances, if without, body swollen on thorax, protuberances 

 pointed, bluntly rounded, truncate, or swollen at distal end; larvapods 

 setiferous, setae few in number; spiracles winged or unwinged; glandubae 

 subsessile or obsolete; leaf-feeders, sometimes gregarious. 



The genus Pteronidea is rich in number of species. The author has 

 examined a large number of specimens representing at least thirty species 

 and including much bred material, and has prepared the following synoptic 

 key for differentiating species. It may be stated here that Pteronidea, 

 together with a few allied genera, is readily separated from all other Tenth- 

 redinidae by the presence of a pair of suranal caudal protuberances on the 

 lateral portion of the caudal margin of the ultimate tergum. Pteronidea 

 thoracica Harrington is unique in lacking the caudal paired protuberances, 

 but is easily distinguished by its characteristic, somewhat elongate, tad- 

 pole-like body, and also by its white head and body and its spreading legs. 

 The color and coloration and the presence of setiferous tubercles and their 

 arrangement are useful characters in separating species. 



SPECIES OF PTERONIDEA 

 1(2) Tenth abdominal tergum without suranal processes; thorax conspicuously swollen; 



thoracic legs spreading out flat laterad; body entirely greenish white; on Primus 



virginiana; Y-141 thoracica Harrington. 



2(1) Tenth abdominal tergum with suranal processes; thorax not conspicuously swollen. ?>. 



3(50) Head black or brov/n; body usually with numerous colored patches 4. 



4(5) Body entirely blackish with distinct yellowish spots on latus; on Salix, Popitlns 



balsamifera, etc.; Y-8.45, M-104, M-182, Y-5-2 ventralis Say. 



5(4) Body not entirely blackish, without distinct yellowish spots on latus 6. 



6(7) Body entirely green; head light brown; suranal processes short, mere swellings; on 



Ribes sp.; Y-1 ribcsi Scopoli (ultimate stage) 



7(6) Body not entirely green; suranal processes usuall}' distinctly pointed, more than 



mere swellings g. 



8(9) Body yellowish with 11 transverse black markings extending between subdorsal 



lines across the venter. Young collection 55 Pkronidia, sp. 1. 



9(8) Body not yellowish, without 11 transverse blackish markings 10. 



