I4-0 CONNECTICUT GEOL. AND NAT. HIST. SURVEY. [Bull. 



segments indistinct toward tip, and saw-guides, black; saw- 

 guides broad and robust, scarcely tapering, rounded at tip; 

 male differs in having more of black on head, thorax for 

 the most part, and dorsum of abdomen, black. Length 



4-5.5 mm pomum 



Head in female with ridges about ocellar basin well defined and 

 thick; clypeus deeply and narrowly emarginate, lobes rounded; 

 head and thorax strongly punctate; frontal crest large, 

 slightly notched; body ferruginous, with antennae, large 

 spot including ocelli, stripe on anterior lobe of mesonotum, 

 stripe in front of scutellum, most of metanotum, and dor- 

 sum of abdomen except at sides and at apex, brownish 

 black. Male differs in having ocellar basin less distinctly 

 defined. Length 4-5 mm desmodioides 



P. atra Marlatt. 



P. hyalina (Norton). Messa hyalina Norton. Larva makes 

 galls on Salix fragilis. New Haven, 19 April, 1910 (B. H. W.). 



P. terminalis Marlatt. Larva makes galls on smooth-leaved 

 willow. 



P. rugulosa Marlatt. 



P. robusta Marlatt. Larva folds the leaves of Fopulus 

 tremuloides. 



P. placenta Norton. Nematus placenta Norton. 



P. populi Marlatt. Larva folds the leaves of Populus 

 grandidentata. 



'P. consors Marlatt. Larva makes galls on Salix sericea. 

 'P. borealis Marlatt. Larva makes galls on Salix sericea. 

 'P. pectoralis Marlatt. 

 'P. acuminata Marlatt. 

 'P. nigrita Marlatt. 



'P. gracilis Marlatt. Larva makes galls on Salix petiolata. 

 P. pallicornis (Norton). Nematus pallicornis Norton. 

 Larva feeds on willow. 



P. pisum (Walsh). Nematus pisum Walsh. Larva makes 

 galls on Salix discolor. New Haven, 20 May, 191 1 (A. B. C). 



P. pomum (Walsh). Nematus pomum Walsh. Nematus 

 hospes Walsh. Larva makes galls on Salix cordata and dis- 

 color. 



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