Data from: Evolved pesticide tolerance influences susceptibility to parasites in amphibians

Because ecosystems throughout the globe are contaminated with pesticides,
there is a need to understand how natural populations cope with pesticides
and the implications for ecological interactions. From an evolutionary
perspective, there is evidence that pesticide tolerance can be achieved
via two mechanisms: selection for constitutive tolerance over multiple
generations or by inducing tolerance within a single generation via
phenotypic plasticity. While both mechanisms can allow organisms to
persist in contaminated environments, they might result in different
performance tradeoffs including population susceptibility to parasites. We
have identified 15 wood frog populations that exist along a gradient from
a close to agriculture and high, constitutive pesticide tolerance to a far
from agriculture and inducible pesticide tolerance. Using these
populations, we investigated the relationship between evolutionary
responses to the common insecticide carbaryl and host susceptibility to
the trematode Echinoparyphium lineage 3 and ranavirus using lab exposure
assays. For Echinoparyphium, we discovered that wood frog populations
living closer to agriculture with high, constitutive tolerance experienced
lower loads than populations living far from agriculture with inducible
pesticide tolerance. For ranavirus, we found no relationship between the
mechanism of evolved pesticide tolerance and survival, but populations
living closer to agriculture with high, constitutive tolerance experienced
higher viral loads than populations far from agriculture with inducible
tolerance. Land-use and mechanisms of evolved pesticide tolerance were
associated with susceptibility to parasites, but the direction of the
relationship is dependent on the type of parasite, underscoring the
complexity between land use and disease outcomes. Collectively, our
results demonstrate that evolved pesticide tolerance can indirectly
influence host-parasite interactions and underscores the importance of
including evolutionary processes in ecotoxicological studies.