372 WILLIAM T. M. FORBES 



stripes on base and fourth segment strongest; and tuft black and yellow, more 

 broadly spreading than usual. Legs contrastingly banded with black and yellow, 

 the hind metatarsus variable in proportions. Fore wing hyaline, like male exitiosa 

 and pictipes, but with the black costal edge broader, because of the wider spacing 

 of the costal veins; discal bar rather thick, and almost wholly bright red. 15 mm. 



Larva imjuiline in oak galls. 



New York to Illinois. New York: Mosholu, Brooklyn. , 



13. C. decipiens II. Edwards. Similar to C. rubristigma; border of fore wing 

 extending in a third way to cell, yellow between the veins. 15 mm. Probably a 

 variety of C. rubrisiigma or its female, (nicotiaiuc H. Edwards, imperfecta H. 

 Edwards. ) 



Mosholu. Xew York; Colorado; Texas. 



14. C. rhododendri Beutenmiiller. Palpi black above, straw yellow below; body 

 black, with strong transverse stripes on segments '2. 4, and 5; anal tuft, in male, 

 large and mostly black. Legs blackish bronze, pale at spurs and joints. Eore wing 

 with scaling almost all black (a few yellow scales) ; outer margin extending two- 

 fifths way in to cell, leaving five hyaline spots; discal bar narrow, black. 9-13 mm. 

 Our smallest Sesian. 



Larva on Rhododendron. 



Xew York; Pennsylvania. Xew York: Ithaca, Brooklyn. 



15. C. bassiformis Walker. Purple-black; palpi yellow with some dark on upper 

 side of terminal segments; vertex with yellow line; female antenna;, as generally 

 in the following species, with the apical half largely Avhite, but extreme tip black. 

 Abdomen with fine yellow stripes on segments 1 to 4 and typically on 6 and 7; 

 the anal tuft narrowly edged with yellow; in the female, with the stripes on 

 4 and heavy, on 3 and 5 light. Hind tibia? yellow below, often mostly black 

 above; the tarsi mostly yellow. Eore wing with border broad, and more or less 

 yellow-scaled; typically with five hyaline cells. 20-25 mm. (lusirans, eupatorii, 

 etc., H. Edwards). (H 46:21.) 



In variety sexfasciata H. Edwards (bollii H. Edwards) there are only four 

 hyaline cells, and the outer border is broader. Variety consimilis H. Edwards has 

 segment 6 as well as segment 5 without yellow. 



August; September. Larva in stem and root of Eupatorium. 



Massachusetts to Wisconsin and Texas. Xew York: Tuckahoe, Staten Island; 

 Sea Cliff, Long Island. 



10. C. scitula Harris. Antennre and palpi as in (7. bassiformis; abdomen with 

 the yellow band on segment 4 typically much heavier than the others, often cover- 

 ing the whole segment ; segment 2 with heavy band, but those on 1 and 7 very weak 

 or absent. Hind tibiae yellow, with a black band between spurs; metatarsi con- 

 trasting, yellow. Wings as in C. bassiformis. 15 mm. (H 46: 29.) 



June and July. Larva reported from under bark of Cornus, oak, hickory, chest- 

 nut. Crata?gus (Wellhouse). and in oak galls; but perhaps mixed with other 

 species. certainly from Andricus galls on oak. 



Distribution uncertain; much confused with pyri. bassiformis, and other species 

 in collections. Glen House, Xew Hampshire. Xew York: Hudson, Long Island. 



17. C. tipuliformis Linna?us. Palpi black on outer face, yellow within. Abdomen 

 with bands on segments 2, 4 and 0, and on 7 of male, that on 6 of male weak; anal 

 tuft black. Hind legs black, with yellow at spurs and joints only. Fore wing like 

 that of C. bassiformis. 20 mm. '(H 46: 20.) 



June. Larva in pith of currant and gooseberry stems: rarely injurious. This 

 appears to be the only northern species which belongs to Chama>sphecia. 



Generally distributed. Xew York : Plattsburg. Buffalo, Ithaca. Kendall, Albany, 

 Staten Island; Pinelawn. Long Island. 



IS. C. pyri Harris Black; palpi yellow, with outer side mostly black; neck 

 black; abdomen with a slender yellow line above, expanding on lower part of side 

 into a patch which reaches base of body ; segment four of abdomen narrowly yel- 



