405] LARVAE OF THE TENTHREDINOIDEA—YUASA 87 



28(29) Latus with distinct more or less continuous longitudinal lines; venter on meson 

 without black spots; C-713 Pteronidea sp. 8. 



29(28) Latus without distinct more or less continuous longitudinal lines; venter on meson 

 usually with black spots 30. 



30(31) Larvapods always with black spots on cephalic aspect; dorsum with setiferous 

 black tubercles more or less uniform in size; abdomen on ventro-meson without 

 black spots; on Ribes sp.; Y-l; M-135 ribesi Scopoli. 



31(30) Larvapods never with black spots on cephalic aspect; dorsum with setiferous black 

 tubercles never uniform in size; abdomen usually with black spots on ventro-meson.32. 



32(33) Larvapods on abdominal segments 4-7 usually with minute black spots on mesal 

 aspect, those on sixth abdominal segment never wanting; abdomen on ventro- 

 meson without black spots; on Salix; Y-95-1; M-155 (in part); M-140 



Pteronidea sp. 9. 



33(32) Larvapods on abdominal segments 4-7 without minute black spots on mesal aspect; 

 abdomen on ventro-meson with black spots 34. 



34(47) Abdominal segments 7-9 on ventro-meson with black spots 35. 



35(40) Ninth abdominal tergum with colored patches on first three annulets, 4, 6, and 4 

 patches respectively 36. 



36(39) Dorsum not shaded grayish-brown 37. 



37(38) On Populus; G-14; M-158 efeta MacGillivray. 



38(37) On hazel; M-110 effusa MacGillivray. 



39(36) Dorsum shaded grayish-brown; on Salix; Y-8.45(?)-2-l Pteronidea sp. 10. 



40(35) Ninth abdominal tergum with colored patches on first three annulets .41. 



41(44) Colored patches on first three annulets 2, 6 and 4 in number respectively 42. 



42(43) Body small, less than 13 mm. in length; Young-49 Pteronidea sp. 11. 



43(42) Body large, more than 15 mm. in length; on Populus balsamifera; M-182; G-pop. 



Pteronidea sp. 12. 



44(41) Colored patches on first three annulets 2, 4, and 4 in number respectively 45. 



45(46) On birch; M-139 emcrita MacGillivray. 



46(45) On Populus; Y-45 lombardae Marlatt. 



47(34) Abdominal segments 2-8 on ventro-meson with black spots 48. 



48(49) Large larvae, 20-23 mm. in length; dorsum without dark shade; head much smaller 

 than thorax in width and height; on Salix; Y-8.45(?)s-5-2. .fulvicrus Provancher. 



49(48) Moderately large larvae, less than 20 mm. in length; dorsum always with dark shade; 

 head comparatively large, only slightly smaller than thorax in width and height; on 

 Salix;M-119 evanida MacGillivray. 



50(3) Head not black or brown, usually greenish with few linear markings; body usually 

 without numerous colored patches 51. 



51(54) Body with a pair of distinct fine latero-dorsal lines; larvapods with 1-2 setae as 

 viewed from side 52. 



52(53) Head with a black line extending the entire length of epicranial stem to the occiput; 

 on Salix; M-12 erudita MacGillivray. 



53(52) Head without black line extending the entire length of epicranial stem to the occiput; 

 on Salix; M-190 Pteronidea sp. 13. 



54(51) Body without a pair of distinct fine dorso-lateral lines; larvapods usually with 3-5 

 setae as viewed from side 55. 



55(58) Head entirely green 58. 



56(57) Suranal process sharply pointed; on Rhododendron canadense; M-46 



Pteronidea sp. 14. 



57(56) Suranal processes bluntly rounded; on Salix; M-133 Pteronidea sp. 15. 



