Influence of the secondary endosymbiont Serratia Symbiotica on the resistance to the parasitism in the aphid Acyrthosiphon pisum

Aphids have an obligate association with the primary symbiont Buchnera aphidicola and is known to affect aphid fitness. Aphids commonly harbour other facultative bacterial endosymbionts and may benefit from their presence through increased resistance to parasitoids [1].
Present results suggest that the ability of hosts to defend against natural enemies depend not only on the presence of symbionts but also on the host genotype. Aphids represent a complex micro-environment for the parasitoid larvae and both the aphid physiology and endosymbiont influence their survival until mummification.