Data from: Nectar bacteria affect life history of a generalist aphid parasitoid by altering nectar chemistry

1. Nectar is a crucial energy resource that strongly mediates the
interactions between plants and animal pollinators or plant defenders.
Previous research has shown that nectar is commonly colonized by
microorganisms, most commonly bacteria and yeasts, which can have a strong
impact on nectar chemistry. However, at present little is known about the
effects of microorganisms on the fitness of animals feeding on nectar. 2.
We used three nectar bacteria representing different metabolic groups
(Asaia sp., Lactococcus sp. and Rosenbergiella sp.) and the common
generalist aphid parasitoid Aphidius ervi (Haliday) (Hymenoptera:
Braconidae) to test the hypothesis that different nectar-dwelling bacteria
affect nectar consumption and insect longevity differently by altering the
chemistry of nectar. 3. Bacteria significantly affected nectar chemistry
by altering its acidity, sugar and amino acids composition/concentration
and by adding compounds synthesized by the microbes. Although inoculation
with bacteria did not affect nectar consumption, a significant difference
in insect longevity was observed. The impact on longevity was species
specific, with Lactococcus being beneficial and Asaia having a detrimental
effect. 4. Bacteria have a strong impact on nectar chemistry and changes
in nectar chemistry may not only influence the foraging behavior of
flower-visiting animals and impact on plant fitness, but also influence
the fitness of nectar-consuming organisms. As effects were species
dependent, changes in nectar chemistry induced by different bacteria may
have contrasting effects on the interactions between plants and insects.
It is therefore essential to know how different microbes alter nectar
chemistry to understand the relationships between plants,
nectar-inhabiting microbes and nectar-consuming animals.