8o 
Journal of Agricultural Research 
Vol.I.No.i 
start to develop in one host, one kills and consumes the other. During 
September in the Salt Lake Basin 88 per cent of the puparia collected 
in the mined leaves of alfalfa yielded adults of Chrysocharis, and the 
two species were about equally represented. Both species have been 
collected in northern and central Utah, southern Idaho, the Imperial 
Valley of California, and in southern Arizona. C. parksi has also been 
reared from mined alfalfa leaves collected at Redding, Cal., in the Sacra¬ 
mento Valley. It was also reared from Agromyza mines in leaves of 
nasturtium and narrow-leaved plantain at Salt Lake City. 
Derostenus arizonensis Cwfd.—This parasite of the larva of Agro¬ 
myza constitutes a new species and is apparently confined to the South¬ 
west. It was reared 
in large numbers by 
Mr. Wildermuth from 
mined alfalfa leaves 
collected in the Salt 
River Valley in Ari¬ 
zona, where it com¬ 
prised 36 per cent of 
the larval parasites so 
reared. Three speci¬ 
mens were reared by 
Mr. Urbahns from 
mined alfalfa leaves 
collected at El Cen¬ 
tro, Cal. 
Fig. 12 .—Chrysocharis parksi , a parasite of the serpentine leaf-miner. 
a. Middle and hind legs of Chrysocharis ainsliei. Greatly enlarged. 
(Original.) 
A single specimen 
obtained from the large number of parasites reared at Salt Lake City, 
Utah, was reared from an Agromyza larva in a leaf of fenugreek ( Trigo - 
nella foenum-graecum). It was described by Mr. J. C. Crawford in the 
Proceedings of the United States National Museum, volume 45, page 
3i5» I 9 I 3* 
Derostenus diastatae How.—This species has been reared from 
mines of Agromyza pusilla in cowpeas at La Fayette, Ind., by Mr. Philip 
Luginbill. In the Eastern States it is an important parasite of Agromyza 
parvicornis and A. angulata. It has not been recorded west of Kansas. 
Derostenus punctiventris Cwfd.*—This insect was reared from puparia 
of Agromyza in mines in leaves of alfalfa at Salt Lake City, by Mr. C. N. 
Ainslie, and by the junior author, from alfalfa and white clover at Salt 
Lake City, Utah, and Lyman, Wyo. It was reared only occasionally and 
is of minor importance as an enemy of this leaf-miner. It also attacks 
Agromyza parvicornis. 
Derostenus pictipes Cwfd *—This parasite was reared from mines of 
Agromyza pusilla in cowpeas at Columbia, S. C., by Mr. G. G. Ainslie in 
1908 and at La Favette, Ind., by Mr. Philip Luginbill in 1911. It was 
