NOTES ON THE COLOURING MATTER OP APHIDES. 167 



List of the Parasitic Hymenoptera ivhich are illustrated 

 in the present and former volume of this Monograph. 



Aphidius cancellatus, Plate IV, fig. 4. 

 ^Coryna Garpenteri, Plate VII, fig. 2. 



— clavata^ Plate LXXXVI, fig. 5. 



— duhia, Plate LXIV, fig. 1. 

 Cynips atriceps, Plate LXXIII, fig. 6. 

 Diodontiis tristis, Plate LXXXVI, fig. 3. 



— minutns, Plate LXXXVI, fig. 4. 

 Ephedras plagiator, Plate VII, fig. 1. 

 Fsen atratuslV\2itQ LXXXV, fig. 4. 

 Trionyx rapce, Plate XL VI, fig. 7. 



Notes on the Colouring Matter op Aphides. 



To those who have mounted Aphides for the micro- 

 scope, in Canada balsam or other preserving fluids, 

 the fact must be familiar that a dye-like substance 

 proceeds from many of the darker kinds, which perma- 

 nently stains these liquids of a fine violet. The marked 

 blood-like stains proceeding from the bodies of the 

 " American blight," Schizoneura lanigera, has been 

 noticed by Smee and others. 



The proximity of the two families Coccus and Aphis 

 might perhaps, lead us to think that this colour had 

 something in it analogous to carmine, which is obtained 

 from an aqueous infusion of Coccus cacti, precipitated 

 by the joint action of a salt of tin and alumina, or a 

 tartrate. If such an identity of colouring matter were 

 an established fact, a chemist would regard it with 

 some interest. 



The colours of Aphides may be roughly grouped 

 into greens, yellows, reds, and dark brown or black, 



* In the explanation of the plate this insect is called Coryne. Pro- 

 bably it is identical with Ceraphron Carpenteri, 



