Fig. 5.

Parasitic wasp preference for volatiles from plants infested with aphids with or without different endosymbiont species. Parasitic wasp (Aphidius ervi) response for volatiles emitted by Vicia faba plants infested with aphids (Acyrthosiphon pisum) with or without different symbiont species. For each symbiont strain tested, the bars show standard errors and the asterisks the significance of the deviation from no choice (t-test: NS: non-significant; *p < 0.05; **p < 0.01; ***p < 0.001). Regiella insecticola (n = 10; column i—cured 319: t ₉ = −0.04, p = 0.4851; ii—cured 126: t ₉ = 0.35, p = 0.6340; iii—microinjected 319: t ₉ = −3.65, p = 0.0026; iv—microinjected 313: t ₉ = −2.81, p = 0.0102), Spiroplasma (n = 10; column v—microinjected 227: t ₉ = −3.40, p = 0.0039; vi—microinjected 237: t ₉ = −4.65, p = 0.0006), Serratia symbiotica (n = 10; column vii—microinjected 619: t ₉ = −2.54, p = 0.0158) and Rickettsiella (n = 10; column viii—microinjected 620: t ₉ = −1.89, p = 0.0456). Natural symbiont infections were removed with antibiotics in the Regiella strains 319 and 126, while the others were artificially microinjected into an aphid clone naturally lacking any secondary symbiont, and which was collected on Lathyrus pratensis