Data for: A diverse parasite pool can improve effectiveness of biological control constrained by genotype-by-genotype interactions

The outcomes of biological control programs can be highly variable, with natural enemies often failing to establish or spread in pest populations. This variability has posed a major obstacle in use of the bacterial parasite Pasteuria penetrans for biological control of Meloidogyne species, economically devastating plant-parasitic nematodes for which there are limited management options. A leading hypothesis for this variability in control is that infection is successful only for specific combinations of bacterial and nematode genotypes.  Under this hypothesis, failure of biological control results from the use of P. penetrans genotypes that cannot infect local Meloidogyne genotypes. We tested this hypothesis using isofemale lines of M. arenaria derived from a single field population and multiple sources of P. penetrans from the same and nearby fields. In strong support of the hypothesis, susceptibility to infection depended on the specific combination of host line and parasite source, w..., Methods to collect the Data
Experiment 1: evaluating the significance of GxG interactions
The objective of this first experiment was to determine if attachment varies with the interaction of host line and parasite source. To do so, we measured attachment rate and load of J2s of four of our P. penetrans sources to our 13 M. arenaria isofemale lines. Attachment rate is the percentage of nematodes with one or more endospores attached. This measurement captures variation between host-parasite combinations in the percentage of hosts susceptible to infection. To measure attachment rate, we counted the number of nematodes with and without endospores for an average of 17.45 ± 0.70 (standard error) nematodes per flask. A second measurement, attachment load, is the number of endospores attached per nematode. Attachment load is estimated only for hosts with one or more endospores attached. Thus, attachment load can capture variation between host-parasite combinations in the number of parasites tha..., The data files are saved in CSV. We used Excel to build the data set and R to analyse the data.Â