Oct. io, 1913 
Serpentine Leaf-Miner 
79 
within the mines of the host and usually some distance away from the 
remains of its victim. Figure 11 represents the pupa of this species. 
The pupal period is seven or eight days, and thus the life cycle of the 
parasite is considerably less than that of the leaf-miner. 
Diaulinus websteri Cwfd.* 1 — Diaulinus websieri (fig. 9, a) is very closely 
related to D . begini and, like the latter, it feeds externally upon the larva 
of its host. In the life-history studies 
made by the junior author at Salt Lake 
City, its habits were in no way distinguish¬ 
able from those of Diaulinus begini , the 
two species being reared together from 
larvae found attached to the same host. Fig - IO - —Larva of Dmuiinm begini. 
Greatly enlarged. (Original.) 
Diaulinus webs ten has been reared from 
Agromyzafrom Kansas, Utah, Arizona, and California, being the most 
abundant parasite reared in southern California and Arizona. Of the 
two species of Diaulinus reared by Mr. Wildermuth at Tempe, Ariz., this 
species constituted 66 per cent of the material, while D. begini comprised 
34 per cent. Of the Diaulinus reared at Salt Lake City D. websteri com¬ 
prised only 18 per cent, while 82 per cent were D. begini . 
This species was reared from mines of Agromyza pusilla in hedge mus¬ 
tard at Wellington, Kans., in 1912, by Mr. E. O. G. Kelly. Mr. C. N. 
Ainslie reared it from mines of Cerodontha dorsalis Loew in timothy 
leaves at Ely, Nev. It is also an enemy of Agromyza parvicornis Loew. 
Chrysocharis ainsiiei Cwfd* and C. parksi Cwfd *—These parasites 
(fig. 12) are very important in the control of Agromyza pusilla 
in the West. They feed internally and emerge from the 
puparia of the host. Their life history is imperfectly known. 
From hibernation material collected at Salt Lake City during 
the winter of 1911-12 adults emerged from April 18 to 20, 
which was 34 days before Agromyza pusilla was captured in 
the fields. 
From studies made by the junior author at Salt Lake City, 
Utah, in 1911 it was noticed that larvae of Agromyza collected 
in the field, which pupated under observation in the labora¬ 
tory, would often yield adults of Chrysocharis exclusively in¬ 
stead of those of Agromyza. Only one parasite issues from 
each puparium of the host, and dissections made of the 
puparia often revealed this to be entirely occupied by the 
larva or pupa of the single parasite, which had entirely con¬ 
sumed its host. But in some instances the puparium of Agromyza when 
dissected revealed two embryo parasitic larvae within the body of the 
host larva. As only one adult is known to emerge from each puparium 
of the host, it is highly probable that when two internal parasitic larvae 
1 The species of parasites marked with asterisks have been recently described in the Proceedings of the 
United States National Museum, v. 43, p. 163-188 (1912) by Mr. J. C. Crawford, Associate Curator, Division 
of Insects. 
Fig. 11.—Pu¬ 
pa of Diau~ 
linus begini. 
Greatly en- 
larged. 
(Original.) 
7954 °—13-6 
