88 ILLINOIS BIOLOGICAL MONOGRAPHS [406 



58(55) Head not entirely green, usually with a blackish or brownish line along epicranial 



stem and one dorsad of each ocellara 59. 



59(64) Suranal process sharply pointed 60. 



60(61) Body tapering caudad uniformly and slightly; uniformly green; on Salix cordala; 



Y-153-1-1,-153-? mendka Walsh. 



61(60) Body not tapering caudad uniformly and slightly; abdomen swollen on segments 



5-7; body not uniformly green 62. 



62(63) Latus of each segment with a large fuscous patch; tenth abdominal tergum with 



caudal margin between suranal processes straight; on Alnus; M-71 



equina MacGillivray. 

 63(62) Latus of each segment without a large fuscous patch; tenth abdominal tergum with 



caudal margin between suranal processes convex; on birch; M-61. Pteronidea sp. 16. 



64(59) Suranal processes never sharply pointed but enlarged at distal ends 65. 



65(66) Antennae with segment 3 complete, altho reduced to a mere line on cephalic aspect; 



on birch; M-60 Pteronidea sp. 17. 



66(65) Antennae with segment 3 incomplete; Y-120 (on Gleditsia triacanthos); Y-143-1 



on Salix cordata trilineata Norton. 



Pontania Costa 



Larvae comparatively small, whitish or greenish, usually 10-15 mm. 

 in length; gall-makers or leaf-edge-rollers; body cylindrical, thorax usually 

 not swollen; tenth abdominal tergum usually with a pair of suranal pro- 

 tuberances; when the paired caudal protuberances are normal in position, 

 i. e., near the lateral ends of caudal margin of the segment, the tergum 

 usually with paired blackish or brownish markings; caudal protuberances 

 sometimes very minute and borne on the caudal margin of the produced 

 median projection; spiracles winged or not winged; third abdominal 

 segment with four annulets, annulets 1-3 setiferous; head usually dark 

 brown or blackish in younger specimens and yellowish or pale brown in 

 older specimens; labrum with mesal emargination shallow or obsolete; 

 maxillary palpi with segment 2 longest, usually nearly equal in length to 

 segments 3 and 4 taken together; antennae with four segments, segments 

 fused or separate, segments 1 and 2 usuallly incomplete and separate, 

 segment 3 sometimes complete, often fused with segment 4; larvapods 

 setiferous, with four or more setae. 



Most Nematinae with gall-making or leaf-folding larvae belong to this 

 genus. The different types of galls are supposed to be specific and are 

 considered of systematic value. Many species are indistinguishable in the 

 immature stages except by the morphology of the galls they produce. 



SPECIES OF PONTANIA 

 I. Gall-Makers 

 1(18) Tenth abdominal tergum with or without the paired caudal protuberances, if present, 

 small, blunt, usually not longer than wide at proximal end, sometimes borne on 

 caudal projection of suranal lobe; tergum without paired blackish or brownish 

 markings; ninth abdominal tergum with distinct paired markings or transverse rows of 

 minute spots 2. 



