*3.2. Field Experiment*

Of the 868 first instar *C. pusaria* caterpillars released for the experiment, 296 (34.1%, Table 3) insects reached pupation. Fungi were detected on 87 out of the 191 dead pupae (45.5%). However, if we consider only Cordycipitaceae (3 species on 37 pupae), the average prevalence of fungal infections drops to 17.3% (2.2% in 2016 and 24% in 2017). The prevalence of fungi was thus considerably higher in the field compared to the lab rearings. The detected taxa (10 species, Table 1) overlapped with those that were identified in the laboratory rearing, except for two species of Mucorales, known as ubiquitous saprotrophs (but see also [24]). The 19 pupae, infected by a member of Cordycipitaceae plus another fungus, sugges<sup>t</sup> that the latter may represent saprotrophs exploiting the already dead moth tissue.

**Table 3.** Demographic parameters of *C. pusaria* in the field experiment. Total sample size is shown in brackets.

