British Braconidm. 13 



refer for the most part to species previously published, or 

 not being conceived upon any fixed plan, they are in 

 general useless for identification. My own opportunities 

 of observing these insects have been too few and too 

 desultory to be of much importance in so wide a subject, 

 and the increased number of species which I am able to 

 record, as well as the facts relating to their habits, are 

 largely due to my friend Mr. Bignell, who with his accus- 

 tomed liberality, entrusted to me his whole collection for 

 a long time. This collection includes the pucerons and 

 their parasites exhibited together, with the necessary notes 

 of their origin, and is probably unique in the kingdom. 

 The Aphides have been named from Buckton's Monograph, 

 while they were fresh ; the parasites were determined by 

 me. I need scarcely remark that this operation involves 

 much difficulty. It appears useless, except in a limited 

 number of cases, to collect specimens at hap-hazard, as 

 they can seldom be identified with certainty. The mi- 

 nute differences which distinguish them, and the dissimi- 

 larity of the sexes, are serious obstacles, which become 

 still more intractable after the drying of the specimens. 

 The only way seems to be, to take from their food-plant a 

 sufficient number of infested Aphides (easily recognised 

 by their swollen and motionless bodies), and to keep them 

 till their parasites come forth : by this means the correct 

 association of the sexes is insured, and their characters 

 may be verified or recorded from fresh specimens. A cer- 

 tain smattering of botanical knowledge is requisite, suffi- 

 cient to name the wild and garden plants of Great Britain ; 

 and also the somewhat rarer accomplishment of a know- 

 ledge of Aphides ; but this latter may always be acquired 

 by the use of Buckton's Monograph. 



A few hyperparasites of the Aphidiides have been ob- 

 served, the commonest being the minute Cynipids of the 

 genus Allotria. It is now certain, from the observations 

 of Bigcell, that these are true hyperparasites, depositing 

 their eggs in the bodies of the Aphidii contained within 

 the pucerons. Other parasites, of less certain habits, 

 belong to the Chalcididae and Proctotrypidse, respecting 

 which it still remains doubtful whether their attacks are 

 directed against the Aphides themselves, or against their 

 internal devourers. I shall take occasion to mention 

 these hyperparasites in their proper places. 



