i907.] White-grubs and May-beetles. 473 



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 blow-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. 



Ophion bifoveolatum 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 fulvus 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 next collected July 

 24, 1906, from among corn roots at Effingham, 111., 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- 



