178 
The species may be characterized as follows : 
2 Black; basal joints of the maxillary palpi, large spot on mandibles, two spots 
beneath anterior wings, membranous regions of thorax, small spot on lower poste- 
rior edge of dorsum of first segment, larger one on second segment, band, dentate on 
basal margin, on apical half of dorsum of third, fifth, and sixth segments, and more 
or less of the lower and apical margin of the remaining segments, lemon yellow. 
Legs black, slender; spot on posterior coxe above, upper side and tip of femora, 
yellow; tibiw and tarsi reddish yellow except tips of posterior tibize and their tarsi, 
which are brownish; last joint and claws of middle and anterior tarsi also brownish. 
Antenne 20-21 jointed, longer than head and thorax, slender to joints 7, beyond 
which the articles are shorter and thickened. 
Wings slightly smoky; veins brown except costal and margin of stigma, which 
are yellowish; a small infuscated spot at base of discoidal vein; second recurrent 
vein joins the third submarginal cell near the base of the cell; cross veins of lanceo- 
late cell slightly curved and oblique. 
Abdomen not much longer than head and thorax, strongly compressed laterally. 
Length, 9-11 mm. 
Exp. al., 16-19 mm. 
g Smaller and more slender thanthe ° ; abdomen less compressed; antennz 18-21 
jointed. Coloration as in 9 except a large spot on the clypeus, one just below the 
eyes in front, the entire pectal region of the thorax, and the posterior margin of the 
third, fifth, and remaining ventral segments, which are lemon-yellow. 
The under side of the coxa, trochanters, and femora, including the apex of the 
latter above, are lemon-yellow; the tibize and tarsi are as in the case of the 9°. 
In some specimens the femora are entirely yellow or with a narrow black line on 
the anterior pair above, and the yellow band on the third ventral segment is occa- 
sionally obsolete. 
Length, 8-9 mm. 
Exp. al., 15-17 mm. 
Habitat: Santa Clara County and Santa Cruz Mountains, California, 
Nevada, and Montana. 
Described from 24 females and I4 males, of which 25 specimens from 
California were bred by Mr. Koebele, and 13 from Nevada and Montana 
were collected. 
The economic importance of this insect arises from the fact that it 
may be expected at any time to abandon its natural food-plant in favor 
of the small grains, on which it can doubtless successfully develop. 
Such changes in the food-habits of our native insects are constantly 
occurring, to the great detriment of our Agriculture, as is illustrated by 
the attacks of the Nematus and Dolerus species on wheat, already de- 
scribed—these insects unquestionably normally affecting wild grass. 4 
PARASITES AND REMEDIES. 
Parasites.—A number of parasites have been found to attack the Saw- 
fly larvee studied. Of these two were reared from Nematus, Lampro- 
nota frigida Cr., and an undetermined form (not found), and an unde- 
termined Ichneumonid (not found) from the Dolerus larvee, described as 
form three. 
On one of the larvee of Dolerus sp. (form 4) occurred three parasitic 
larvee (Huplectrus ? sp.) attached externally to the dorsum of the first 
