175 



Tlio newly liatohed larva (Fio-. 14, h) is from 3 to 4 mm. long, rather 

 slemler and elongate and tapering gradually from the head to the last 

 segment; head yellowish, eyes black. Full growth is attained in about 

 five weeks. The mature larva (Fig. 14, c) has a length of from 17 to 20 

 mm. and has the general form of the newly hatched larva. The head is 

 considerably less in diameter than the first thoracic segment and is of 

 a pale clay yellow with a greenish tinge and with the surface slightly 

 reticulated; the eyes are black and surrounded by a narrow dark brown 

 ring. The mandibles are tipped with brown. Tlie color of the body is 

 green or yellowish green, with the alimentary canal showing through 

 the semitransparent dorsum as a line of darker green. A whitish line 



Fig. U. — Xematius m a ry la adieus Korton: a a, eggs in -wheat blades ; b, young larvae; c, full-grown 

 larva: d, cocoon from which an adult has emerged; e and/, adult insects — e, male;/, female; a and b, 

 natui'al size: cto/, enlarged (original). 



crosses the stigmata, which are very small and light brown in color. 

 The head and body below the stigmata are armed with minute hairs, 

 which are light colored except on the last segment, where they are 

 prominent and brownish. 



The larva of this insect is at once separated from the Dolerus larva 

 by the possession of but seven pairs of abdominal feet, in which respect 

 it agrees with a large group of Tenthredinid larvse (Nematinae), includ- 

 ing the genus Nematus and its allies. 



The larvse at first feed together as shown in the illustration, but 

 separate and are practically solitary later. They feed on the wheat 

 blades and have not been observed to cut off the wheat heads, though 

 there is little doubt that they will do so, since the stalk just beneath 

 the head remains green longest. 

 12201— No. 5 2 



