Coinfection accelerates transmission to new hosts despite no effects on virulence and parasite growth

One of the fundamental aims of ecological, epidemiological and evolutionary studies of host-–parasite interactions is to unravel which factors affect parasite virulence. Theory predicts that virulence and transmission are correlated by a trade-off, as too much virulence is expected to hamper transmission dueowing to excessive host damage. Coinfections may affect each of these traits and/or their correlation. Here, we used inbred lines of the spider- mite Tetranychus urticae to test how coinfection with T. evansi, impacted virulence-transmission relationships, at different conspecific densities. The presence of T. evansi on a shared host did not change the relationship between virulence (leaf damage) and the number of transmitting stages (i.e., adult daughters). The relationship between these traits was hump-shaped across densities, both in single and coinfections, which corresponds to a trade-off. Moreover, transmission to adjacent hosts increased in coinfection, but only at low T. urti..., , , # # Coinfection accelerates transmission to new hosts despite no effects on virulence and parasite growth

\[[https://doi.org/10.5061/dryad.zw3r228gk\]’https://doi.org/10.5061/dryad.zw3r228gk’](https://doi.org/10.5061/dryad.zw3r228gk]’https://doi.org/10.5061/dryad.zw3r228gk’)

## Description of the data and file structure

 
The data were collected from 2 laboratory experiments in which different inbred lines of *T. urticae* were used to measure virulence ‘damage to 2cm2 bean leaf fragments’ and transmission, measured as movement between 3 bean leaf fragments linked by 3 cm Parafilm ‘plastic’ bridges. Missing data are denoted as n/a.

### Files and variables

#### File: Godinho\_FINAL.xlsx

\**Description:** There are 3 data sheets.
 
The data from the first experiment are in the sheet: ‘Experiment1_WithinHostMeasures’.

The variables are:

Column A ‘Block’, this is the temporal experimental block measures were taken.

Column B ‘Line’, is the *T. urticae* inbred line.

Column C ‘ID2’ is...