42 



bloom on the surface. The larva is of the normal tenthredinid form, 

 the surface not very strongly v^'rinkled. 6-annulate. smooth, and not 

 shining: the head is pale, nearly white, or pale green tinged v^'ith 

 brown, clypeus with a distinct brown spot, a brown band sometime> 

 present above the clypeus. head usually darker on the upper third : 

 eyes black, mouth-parts dark brown, tips of mandibles darker: the 

 lateral surface, as well as the lower, varies from pale yellowish to 

 pale but distinct green, this color extending from the line of the spir- 

 acles, the darker coloration of the dorsal surface often almost envelop- 

 ing the spiracles: body slightly brownish in the folds; spiracles 

 small, elongate-oval, black. Segment 13 is much paler dorsally than 

 the remaining segments. Besides the three pairs of nearly white 

 thoracic legs, which are more or less infuscated at the stttures, there 

 are eight pairs of abdominal legs (segments 6 to 13). which are also 

 pale. Length. 13 mm. : Avidth. nearly luiiform from the second 

 thoracic to the antepenidtimate segment, 1.5 to 2 mm. 



Antepenultimate stage. — What appears to be the antepenultimate 

 stage closely resembles the mature form, but is less greenish in color 

 and has a proportionately larger head. In this stage, larva? are pale 

 green, with a somewhat irregular, ill-defined, broad, darker green 

 space on the sides jtist above the spiracles: white piliferous tubercles, 

 somewhat faint, but quite noticeable in living specimens, occur in this 

 stage. Length, 10 to 11 mm. : width, 1.2 mm. 



Younger stage. — A still earlier stage was represented by very few 

 specimens and was very much darker. Dorsal surface pale brown, 

 shading into black at the sides: piliferotis tubercles distinct, large 

 and white, arranged in regttlar sets: head almost uniformly dark 

 brown. Length, 7 to 10 mm. ; width, 0.9 to 1 mm. 



Larva? placed in a rearing cage in the insectary did not feed on 

 sugar-beet leaves, but when dock was substituted fed tmtil maturity. 

 From these larvae three adults issued September 2-1. Larva? kept by 

 the jtmior author with him on his trip westward were confined in a 

 small tin box and fed on beet leaves. From these one adult issued 

 October 3. The larva from which this adult came formed a naked 

 pmpa in the box September 23, and this pupa was kept wrapped in a 

 beet leaf until the adult issued. 



The pirpa. — The pupa is at first pale green, with dark extremities 

 and tips of feet and ]3alpi brownish. Before the adult emerges the 

 pupa darkens considerably. Length, 10 mm. 



The adult. — The general appearance of the adttlt sawfly and the 

 arrangement of the venation of the wings is shown by figure 15, a. 

 A brief characterization of the genus was given by Xorton in 1868,« 



Trans. Amer. Ent. Soc, Vol. II, p. 211. 



