Data for: Does parasitoid species diversity promote protective symbiont diversity?

How does diversity in nature come about? One factor contributing to this diversity are species interactions; diversity on one trophic level can shape diversity on lower or higher trophic levels. For example, parasite diversity enhances host immune diversity. Protective symbionts mediate host resistance and are therefore also engaged in reciprocal selection with their host’s parasites. Here, we applied experimental evolution in a well-known symbiont-aphid-parasitoid system to study whether parasitoid diversity contributes to maintaining symbiont diversity. We used caged populations of black bean aphids (Aphis fabae), containing uninfected individuals and individuals infected with different strains of the bacterial endosymbiont Hamiltonella defensa, which protects aphids against parasitoids. Over multiple generations, these populations were exposed to three different species of parasitoid wasps (Aphidius colemani, Binodoxys acalephae, or Lysiphlebus fabarum), simultaneous or sequential mi..., Data on aphid demograph from the experimental evolution experiments (\"basic\") was collected by counting aphids (roughly estimated by counting aphids in groups of ca. 10 individuals) and mummies (exact counts) and measuring plant size (i.e. total stem length of all plants) for each pot in each cage. Prior to data analysis, data for each cage was combined to obtain a single value for each cage in each generation (see associated paper for details).
To analyse H. Defensa composition (\"mol\") we first collected aphids at the end of generations 3 and 6, extracted their DNA, used diagnostic PCRs to amplify part of the bacterial 16S rRNA and part of H. defensa's murE gene for sequencing to distinguish H. defensa haplotypes. Data was recorded as either H. defensa absent or present and in the later case the identity of the haplotype. From this we calculate the proportion of H. defensa negative aphids and each H. defensa haplotype. This proportion was used in subsequent analysis (see associated pap..., , # **Data for Does parasitoid species diversity promote protective symbiont diversity?**

### Experimental procedures

We conducted an experimental evolution experiment with 30 replicate populations (cages) over six generations each with the same initial composition of different haplotypes of the protective symbiont Hamiltonella defensa or no H. defensa. In each generation our artificial populations were exposed to different wasp species either individually or in combination. In each generation we collected data on aphid demographics and in generation three and six. In addition we conducted infection tests using each possible symbiont haplotype – parasitoid species combination.

### Results

Contrary to our expectations we found little effect of parasitoid treatment on *H. defensa* composition.

## **Description of the data and file structure**

### basic.txt:

Data on aphid demographics collected during transfer in each generation.

* id1: Unique identifier for each pot-generation com...