125 
buff color, and with a soft exterior surface, in touch as well as 
in color reminding one of the punk used by dentists. Upon 
cutting this cocoon open, it will be found to consist of about a 
dozen delicate layers, the outer ones soft and loosely spun, the 
inner ones more and more compact and paler in color. Within 
this cocoon, if fr^sh, there will be found a whitish grub which, 
though lacking legs, has the joints of the body, at the sides, 
swollen so as to look like the fleshy pseudopods possessed by 
many larvae. * * * From having repeatedly found the head 
parts of some Lamellicorn larva attached to these cocoons, I 
had long suspected that such larvae formed the food of this 
Tiphia, and on carefully examining these head-parts I recognized 
them as belonging to the common white grub. But all doubt 
as to this fly being parasitic on said white grub ceased when, in 
1872, Mr. A. W. Smith, of St. Louis, brought me a number of 
the cocoons which he had taken from a low part of his farm on 
the Illinois bottom, where the white grub was very thick, and 
the yellow cocoons so numerous as to attract attention. v * 
Ophion bifoveolatum is likewise reported by Bilev as a white 
grub parasite (Proc. Ent. Soc. Washington, Yol. II., p. 134), 
and this was quite probably the species of Ophion bred at 
my office in 1886. From white grubs brought to the insectary 
April 27 the specimen emerged May 11, but was lost from my 
collections before being determined specifically. 
A tachinid fly has also been found parasitic on the grubs 
(Proc. Ent. Soc. Washington, Yol. II., p. 134), and a second fly, 
Microplithalma nigra , Macq., has been repeatedly bred by us 
from the dead bodies of white grubs. The habits of the family 
Dexidm, to which this last mentioned insect belongs, make it 
doubtful, however, if these flies may not have developed from 
eggs laid on the bodies of grubs already dead. 
Tiphia iuornata> mentioned above, ought probably to be called 
a predaceous father than a parasitic insect, as it attacks the 
grub from without, and devours it bodily. Ants destroy white 
grubs in breeding cages,! and very possibly attack them some¬ 
times in the field. It is quite likely that various other preda- 
* “Tiphia inornata. Larva.— Length 0.25-0.50 inch when full grown; greatest diameter 
Vz the length; largest in middle; 12 joints and a subjoint, exclusive of head. Head bent over 
on the breast. Color translucent-white, with a broad, transverse, opaque wrinkle around 
each joint; on all the stigmata-bearing joints except 1, this wrinkle is constricted into two 
ellipsoidal pieces dorsally, strongly bulging laterally into semi-oval tubercles, like pseudo¬ 
pods, and subobsolete ventrally. Labrum edged with brown. Stigmata small, circular, 
brown, and placed on posterior part of joint 1, and on anterior part of joints 4-11. Anal 
slit transverse. 
“Desciibed from 13 specimens. The color becomes more yellowish in alcohol. 
“Imago.— This inject is very variable in size. 2 male, 7 female specimens which I have 
bred from the cocoon ranging from 0.35 to tU'>8 inch in length of body. The wings are either 
very faintly or more deeply smoky-yellow. The color is jet black,but on my largest female a 
faint bluish or purplish hue is noticeable. In studying by the light of the specimens before 
me. Say’s three descriptions which follow, I am forced to the conclusion that they all refer 
to but one species. Certain features common to all the specimens are curiously omitted in 
one or other of the descriptions, and inserted in one or both the others, while every feature 
mentioned belongs to the one species taken in its variations. It becomes a question, in 
such a case, which name to use, but I employ the first because it is appropriate, and seems 
to have been the only one used by subsequent authors.”— C. V. Riley. 
+ Fifth Ann. Rep. Vt. Agr. Exper. Station (1891), p. 153. 
