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Indiana University Studies 
more yellow than in the female; eyes enlarged (little 
or greatly) ; third antennal segment usually lengthened 
and curved; thorax more elongate than in the female; 
galls simple swellings, inseparable, usually polythah 
amous (monothalamous in dubius, and always on anthers 
and cupules) ; North America; alternate generations 
largely identical except that one is bisexual, the other 
agamic (or largely agamic). 
Subgenus Dolichostroplius, 11 
3. Eyes of female rather large, considerably enlarged in 
the male, cheeks narrow, not protruding beyond the eyes ; 
mesonotum in large part naked; galls on leaves, buds, 
or bark, always separable, monothalamous. 4 
Eyes small, the cheeks broad, protruding beyond the eyes ; 
antennge with 14 segments, the third hardly longer than 
the fourth; mesonotum wholly hairy; gall a woody stem 
swelling, inseparable, polythalamous ; Old World species. 
Subgenus Pseudoneuroterus 
4. Malar furrow distinct; antenna with 14 segments, the 
third hardly longer than the fourth; the third distinctly 
curved in the male ; tarsal claws simple ; male with radial 
area closed; galls globose, in buds or on bark; eastern 
North America. Subgenus Neospathegaster, 18 
Malar furrow faint; antenna with 15 segments (14 in a 
few individuals), the third half again as long as the 
fourth ; the third hardly curved in the male ; tarsal claws 
toothed ; male v/ith radial area open ; galls on leaves, with 
more specialized forms; Old World species. 
Subgenus Spathegaster 
Subgenus Diplohius 
5. Mesonotum or mesopleura or both finely roughened; leaf 
and stem galls, polythalamous, monothalamous only if on 
anthers. 6 
Mesonotum and mesopleura smooth and shining; leaf 
galls, always monothalamous. 7 
6. Mesonotum and mesopleurse finely roughened ; male 
largely brown and yellow; galls are anther capsules; 
California; on Q. Douglasii. , N. floricola 
