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Ipre&acioue an^ parasitic Enemiee of 



tbe Hpbi&ea 



(tncluMnci a Stu^p of 1b^per*=patasttes)» 



By H. C. a. Vine. Plates VIII. and IX. 



S it is only among the larval forms of the Syrphidae 

 that the aphis-eaters are to be found, it is of great 

 interest to identify if possible the respective larvae, 

 in order to ascertain in what species the aphidivor- 

 ous habit prevails. The principal difficulty 

 encountered in this study is the fact that fully 95 

 per cent, of the imagines, reared at great expendi- 

 ture of time and trouble, prove to be the common 

 Syrphus luniger, or some nearly allied variation. Another difficulty 

 is caused by the irregular periods of abstinence which more or less 

 affect all these larvae, and during which they not infrequently die 

 from the attack of some species of fungus. I have, however, 

 succeeded in placing beyond doubt the position of three aphidivo- 

 rous larvae, and these, with the addition of one species which I 

 have as yet failed to rear to maturity, comprise all which I know 

 to be aphis eaters. 



The eggs or young grubs have been obtained in different 

 localities around Bath and near Radstock, Somerset, and by the 

 kindness of Mr. C. J. Watkins, numerous specimens have been 

 sent me from Pains wick, Gloucestershire. Hence the specimens 

 observed may be taken to be fairly representative of English 

 species. 



A vast proportion of the larvae, wherever collected, are more 

 or less rough in skin, brown, or very dark grey, finely speckled 

 with black, sometimes beset with small spines, and having a more 

 or less black, or occasionally coloured, lines, visible through the 

 transparent outer skin, down the centre of the dorsum. These 

 larvae form pupa cases, of a dark grey brown, coffee brown, or 

 brown black, which retain the finely sprinkled black specks of the 

 larvae, and frequently exhibit slight oblique marks of lighter or 

 darker colour, together with five dark lateral spots, and in some 



International Journal of Microscopy and Natural Science. 



Third Series. Vol. V. k 



