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living grubs kept in breeding-cages in my insectary. Adults have 
emerged in these experiments March 26, June 8, July 12, and Au- 
gust 8, and others have been taken at electric lights July 9, and in a 
corn field September 27. Those appearing March 26 lived in con- 
finement until May 14. We have thus seen these insects alive in 
every month from March to September inclusive. In the breeding- 
cages, remains of a white-grub were commonly found associated 
with the cocoon of the parasite. 
The adult of this species is a large blackish-gray fly with a gen- 
eral resemblance to the common large blo\v-fly, but with a grayish 
white sheen on the basal half of each segment of the abdomen, giv- 
ing the effect of equal alternating cross-bands of black and gray. 
OpJiion hifovcolatum Brulle. — This well-known parasite of the 
white-grub has been, reared by us several times from these insects. 
In one case the head and skin of a grub were woven into the wall of 
the cocoon of the parasite. The species has been bred by us repeat- 
edly from cocoons collected from the latter part of July to the first 
of September, and kept in breeding-cages through the winter, adults 
appearing from March 31 to April 27. 
The adult is a large, slender-bodied, dark red ichneumon-fly; 
and the cocoon is quite regularly elliptical, a half inch long by a 
fourth of an inch thick at the middle, smooth, dull brownish, or 
more or less blackish — especially towards the end. 
SparnopoHus fulvns Wied. — This bee-fly, which we have some- 
times noticed in corn fields and have collected from miscellaneous 
sweepings of vegetation in midsummer, also proves to be a parasite 
of the white-grub, as shown by breeding-cage work done in 1904 — 
1906. It was first detected in this relation by Mr. E. P. Taylor, of 
my office, who found a white-grub at Elliott, 111., August 25, 1904, 
with a dipterous larva attached to its back. This was placed in an 
insectary cage, which was not examined until April 21, at which 
time the white-grub had been completely destroyed, and the larva 
had completed its transformations. It probably had emerged in the 
fall of 1904. A larva of this same species was nejct collected July 
24, 1906, from among corn roots at Effingham, III, and was placed 
in a breeding-cage to obtain the adult. It pupated August 22, and 
emerged as a winged insect September 10. All our open-air collec- 
tions of this fly have been obtained in August. 
The adult is about as large as a common house-fly, but is covered 
with erect yellow fur. The pupa is not inclosed in the last larval 
skin. Its head bears three large points on each side anteriorly, and 
a smaller pair beneath at the base of the mouth-parts. The last seg- 
