4U EDWARD NORTON. 



Genus I. CIMBEX. Oliv. 

 Cimbcr, Oliv., Ent.. 1789. 

 Crabro. Geoflr., Hist, des Ins., 1764. 

 Tenihrcdo, Linn., Fabr., Ac. 



Wingx with two marginal and three submarginal cells; first ^w^)- 

 margiiial receiving two recurrent nervures ; lanceolate cell with 

 straight cross-line; under wings with two middle cells; stigma length- 

 ened, hardly wider than costa ; costal edge wavy on each side of stig- 

 ma. Bullae in the submarginal cells as follows : one at the point re- 

 ceiving the first recurrent nervure, one below the middle of first cross 

 nervure, and two, one near the bottom and one near the top of second 

 nervure. 



Antnuise clavate, 7-articulate, third as long as fourth and fifth ; 

 soldered, oblong-ovate. 



Head as wide as th(n-ax, labrum narrow, hardly visible below the 

 nasus ; mandibles 3-dentate. 



Boilij stout, obscurely villose. Abdomen ovate in the females, 

 cylindrical in males, with a deep, whitish, membranous notch, which 

 is apparently in first segment of tergum, but is really the basal mem- 

 brane between the basal plates of metathorax. 



Legs. — Femora unarmed, the two posterior pair much thickened in 

 males, with a shallow channel beneath to receive the bent tibiae; tibiie 

 with two obtuse spurs at apex ; anterior tarsi with obtuse processes be- 

 neath ; a strong hook at tip of first joint of posterior tarsi of males; 

 claws simple. 



Larvse. twenty-two-footed, (6 pectoral, 14 abdominal, and 2 cau- 

 dal,) solitary ; bodies without hair, except in numerous small setiger- 

 ous tubercles. But one brood during the year. They rest in a spiral 

 position, tail inward, on the under side of leaves, and when disturbed 

 sometimes eject a fluid from pores above the spiracles. 



They form a strong, brown, oval cocoon, which drops to the ground 

 with the falling leaves, and remains on the surface during the winter, 

 the insect coming forth in June or July. This is the largest of tlu- 

 Tenthredinidjo, but does not appear in such numbers as to be injuri- 

 ous to vegetation. 



1. C americana. 



C'lmbex americana, Leach, Zool. Misc. Ill, 1817, 104. 'J,. 

 Lepel, Mon. Tenth, ".ii, 87. 

 Harris, Inj. Ins, 519, % 9 , fis;;. 24:?. 

 Norton, Proc. Ent. Soc. Thil. I. 201. 

 Cimhcx femorata, Kirby, Faun. Bor. Am., 254, %. 

 Steel blue; abdomen purple tinged, in the females more or less spotted with 

 yellow-white; antenna? and tarsi in part testaceous ; wings variable. Length 

 0.80— LOS. Br. wings 1.80—2.28 inch. 



