PLATE LXVIII. 



Aphis instabilis. (Page 94.) 



Fig. 1. — Apterous viviparous female. 



Figs. 2 and 3. — Varieties of tlie pupa. 



Figs. 4 and 5. — Varieties of the winged female. 



Aphis sambucaria. (Page 95.) 



Fig. 6. — Oviparous female, showing two advanced 

 ova. 



Fig. 7. — Winged male. c. Cornicle of the vivi- 

 parous female. 



