APHIDIVOROUS HYMENOPTERA. 149 



" Assuming that the Aphis is again resuscitated in 

 May there are about seven months of the year in 

 which the entire species is reduced to a condition 

 analogous to that of an annual plant whose vital 

 powers are transferred to its seeds, liable to dispersion 

 through the sport of accident — to be swept off by the 

 torrent or scattered by the wind." 



The nests of this species often contain " blobs of 

 honey-dew," covered with a film of the white dust 

 which covers the insect. I have before noticed that 

 this curious secretion is often abundant in the curled 

 leaf -tufts of the Schizoneura of the elm. 



It will be noticed that Brachycohis stellar 103 has an 

 economy very similar to that of the preceding species, 

 C ryptosiphum artemisice, which also constructs con- 

 torted leaf-tufts. 



Aphidivorous Hymenoptera. 



The predatory and parasitic habits of the Ichneu- 

 monidse are too well known to allow here of more than 

 a passing sketch, and it will be well to confine our 

 remarks pretty much to such as relate only to the 

 economy of Aphides. Such a notice perhaps, will be 

 thought legitimate, inasmuch as numerous minute 

 species of the Hymenopterous group — a group which 

 Messrs. Kirby and Spence considered probably com- 

 posed one-fourth of the whole insect world — exert their 

 powerful influence in keeping down the redundance of 

 life of the Aphis family. 



The predaceous Hymenoptera of Great Britain have 

 been estimated by Westwood to comprise, at the very 

 least, three thousand species. 



Of the two great sections Terehrantia and A.culeata 

 of Latreille, concerning the first it will only be neces- 

 sary to remark on the Aphidivorous Cynipidse, Ichneu- 

 monidse, and Chalcidise ; and as to the second section, 

 viz. the Aculeata, to treat on some of the more impor- 



