PARASITE, APHTDIUS TESTACEIPES. 117 



with these synonyms collectively under A. testaceipes. The hosts 

 then would be as follows: Reared from Macrosiphum cucurbits by 

 the senior author at Lafayette, Ind.; reared from an aphidid on 

 Eragrostis sp., by Mr. D. W. Coquillett; reared from Macrosiphum 

 sp. on Audibertia stochoides, by Mr. Coquillett, at Los Angeles, Cal. 

 Swept from Eragrostis sp. by the senior author at La Fayette, Ind., 

 October 4, 1885; reared from Myzus sp. on HosacJcia glabra by Mr. 

 Coquillett at Los Angeles, Cal.; reared from Myzus rife (currant 

 aphis) by Prof. A. J. Cook, Lansing, Mich.; reared from Aphis gos- 

 sypii by Prof. G. F. Atkinson, Columbia, S. C; reared from Macro- 

 siphum sp. on Abutilon by Mr. Coquillett at Los Angeles, Cal. ; reared 

 from Aphis avense by Mr. J. W. Barlow, June 20, 1882, at Cadet, Mo.; 

 reared from Aphis on peach May, 1886, by Mr. Albert Koebele, 

 Fresno County, Cal.; reared from an aphidid on Baccliaris viminalis 

 by Air. Coquillett at Los Angeles, Cal. 



There are probably many other hosts besides the ones we have 

 mentioned of which as yet we have no knowledge; and when this 

 situation is taken under consideration it is very easy to see that it 

 would be only in rare instances and under peculiar conditions that 

 a locality would be found where Aphidius testaceipes would not be 

 lurking, waiting for favorable weather conditions and abundant 

 supplies of its host aphidids to make its appearance in greater or less 

 numbers. 



HIBERNATION. 



Aphidius is capable of withstanding extreme degrees of cold, as 

 witnessed by the fact that Toxoptera parasitized during November, 

 1907, at Richmond, Ind., did not give up adults until the 27th and 

 28th of March and the 4th of April following. During February they 

 were in the larval stage within an old dead body of a Toxoptera. 



Mr. Kelly found that at Leavenworth, Kans., the parasites hiber- 

 nated as larvae and pupae. This was shown by the fact that he found 

 Aphidius testaceipes in the field in this condition on November 13, 

 1907. From a lot of 50 dead parasitized Toxoptera from the same 

 field, that had been washed or rubbed off the leaves of the young 

 grain and were taken out of the mud about the wheat plants on 

 February 28, after the winter was practically over, Mr. Kelly found 

 that 17 contained full-grown larvae, 12 contained pupae of a light 

 color, and 21 contained pupae of a dark color; the latter apparently 

 were ready to develop promptly with the advent of warm weather. 

 Mr. Kelly collected, on the same date and also from this same field, 

 a number of Toxoptera in various stages of development that were 

 hibernating in the fields and which showed no signs of parasitism; 

 the weather had been such as to preclude the possibility of their 

 having recently been parasitized. These were placed in a warm 

 room and soon showed evidence of parasitism, Aphidius testaceipes 

 being finally reared from them. 



