This dataset contains data from a meta-analysis on the benefits and costs of hosting secondar symbionts in plant-sucking insects, as described in the paper: "Zytynska, S.E., Tighiouart, K. & Frago, E. (2021) Benefits and costs of hosting facultative symbionts in plant-sucking insects: A meta-analysis. Molecular Ecology https://doi.org/10.1111/mec.15897 "

Many animals have evolved associations with symbiotic microbes that benefit the host through increased growth, lifespan, and survival. Some interactions are obligate (essential for survival) while others are facultative (beneficial but not essential). Not all individuals host all facultative symbionts in a population, and thus there is likely a trade-off between the cost of hosting these symbionts and the benefits they confer to the host. Plant-sucking insects have been one of the most important models to test these costs and benefits experimentally. This research is now moving beyond the description of symbiont effects towards understanding the mechanisms of action, and their role in the wider ecological community. We present a quantitative and systematic analysis of the published evidence exploring this question. We found that whitefly and true bugs experience benefits through increased growth and fecundity, whereas aphids experience costs to their fecundity but benefits through increased resistance to natural enemies. We also report the lack of data in some plant-sucking groups, and explore variation in effect strengths and directions across aphid host, symbiont and plant species thus highlighting the importance of considering the context dependency of these interactions.

Meta-analysis: The main inclusion criteria across the groups were: (1) data on at least one insect species; (2) an experimental test of facultative symbiont effects on insects, either experimentally cured of a symbiont, or inoculated with one (Experimental), or a comparison of field-collected infected and uninfected aphids (Natural); (3) any of the following types of variables tested: any behaviour, growth, fecundity, survival, or parasitism-resistance related variable; and (4) data on means, an estimation of variation, and sample size. In addition, we only included studies that used artificial curing methods (e.g. antibiotics) with demonstrated negative effects on symbionts, but not their insect hosts. If novel methods to remove symbionts were used, we only included studies that demonstrated that the technique used had no direct negative effects on insect fitness.

Analysis: data were analysed in R using metafor package.

The ReadMe file contains an explanation of each of the variables in the dataset, the extracted data, the assigned group and the associated values of Hedges' g used in the meta-analysis (also see the R code file). 

Three datasets

(1) main dataset for Heteroptera, whitefly and aphids

(2) aphid dataset for host-plant effects

(3) aphid dataset for multiple hosting of symbionts