177 



A single specimen <»f the liymenoiiteious parasite Lampronota frig- 

 ida Cr. was reared from a eocoon of this Saw-fly and also an luuleter- 

 miued species (not fonnd). 



CEPHUS OCCIDENTALIS M. SP. 



The Cephus sp. referred to in the opening of this article as being 

 reared from grass in California by Mr. Koebele proves to be iinde- 

 seribed. 



The habits of this insect are exactly similar to the European Corn 

 Saw-fly CcphuH pygmwufi^ the larvie boring in grass working from the 

 top towards the root and spinning in the base of the grass stem a silken 

 tube in Avhieh it hibernates. 



Before spinning up the grass stem is partly cut through (Fig. 15, c) 

 to facilitate the emergence of the adult insect which takes jdace in May. 



Fig. 15.— Cephus occidentalis u. sp: a, larva; b, adult insect, female; cbase of grass stalk showing 

 excavation of larva, all inclosed (original). 



The larva (Fig. 15, a) is about one-half inch long, cylindrical, whitish 

 in color and with a resinous brown head. The general characteristics 

 of shape and structure are shown in the figure. It does not differ from 

 the larva of Gephm pygmieus except in being smaller and less robust. 



The adult insect (Fig. 15 h) agrees almost exactly with Cephus pyg- 

 ma'Ufi in coloration, coming much closer to it in this respect than to any 

 other American species, but is in every way more slender and graceful 

 and would never be mistaken for the European species. The head is 

 narrower in jiroportion to the body and is more globular when viewed 

 from the side. Viewed from above it narrows more posteriorly from the 

 eyes than pygnumis. The grass in which this insect breeds was not de- 

 termined, but is a hollow-stemmed marsh grass, probably a species of 

 Elymus. 



