Learning can be detrimental for a parasitic wasp: R scripts and Telenomus podisi data

Animals have evolved the capacity to learn, and the conventional view is
that learning allows individuals to improve foraging decisions. We
describe a first case of maladaptive learning where a parasitoid learns to
associate chemical cues from an unsuitable host, thereby re-enforcing a
reproductive cul-de-sac (evolutionary trap). Telenomus podisi parasitizes
eggs of the exotic stink bug Halyomorpha halys at the same rate as eggs of
its coevolved host, Podisus maculiventris, but the parasitoid cannot
complete its development in the exotic species. We hypothesized that T.
podisi learns to exploit cues from this non-coevolved species, thereby
increasing unsuccessful parasitism rates. We conducted bioassays to
compare the responses of naïve vs. experienced parasitoids on chemical
footprints left by one of the two host species. Both naïve and experienced
females showed a higher response to footprints of P. maculiventris than of
H. halys. Furthermore, parasitoids that gained an experience on H. halys
significantly increased their residence time within the arena and the
frequency of re-encounter with the area contaminated by chemical cues.
Maladaptive learning in the T. podisi - H. halys association is expected
to further decrease parasitoid reproductive success and have consequences
for population dynamics of sympatric native and exotic host species.