All in all, this is the first paper looking at the effects of aging in aphid honeydew on not only the bacterial community but also the volatile community. To me this also raises the question if the hoverfly eggs would also have a higher emergence rate on these ages of honeydew.

Interestingly, the high presence of alcohols and ketones were not as interesting for the oviposition of E. balteatus, mostly preferring either fresh honeydew or 72 hour aged honeydew.

Further, we found that the volatilome of 24 hour aged A. fabae honeydew was dominated by Alcohols and Ketones, but after 24 hours no volatile class dominated the volatilome anymore. Likely indicating changing metabolism in the bacterial community.

As both honeydews aged, the relative abundance of these bacteria decreased, but the relative abundance of Acetic acid bacteria (i.e. Acinetobacter) and commensal bacteria (i.e. Staphylococcus) increased. Likely indicating that the aphid inhabiting microbes need the aphid environment to survive.

Interestingly, we found that the early community harbored a higher concentration of obligate endosymbionts such as Buchnera and gut-associated bacteria such as Erwinia.

We found that A. fabae honeydew harbored a more diverse bacterial community than A. pisum and also excreted a higher dose of volatiles than A. pisum honeydew.

We collected honeydew of both the black bean aphid (Aphis fabae) and the pea aphid (Acyrthosiphon pisum). Afterwards we let the honeydew age in open air for up to 72 hours. We sampled both the volatilome, bacterial community & oviposition preference of Episyrphus balteatus every 24 hours.

So like, if you're from Bremen and can help, please DM me 🥹