The Influence of Pesticide Exposure on Route-specific Infection
Outcomes
While oral infection with Btt did not result in immediate excess
mortality compared to unexposed individuals, we considered the
possibility that infection outcomes could be exposure route-specific. To
determine whether the interaction between pesticide resistance, exposure
to pesticides, and infection outcomes might be route-dependent, we
septically infected susceptible and OP-selection regime larvae exposed
to control and OP diets. Individuals from the susceptible regime that
were exposed to OP had lower survival against septic Bttinfection compared to the other groups (Fig. 2; Suppl. Table 6)
indicating an outsized cost of combined OP exposure and septicBtt infection in control regime larvae. This result contrasts
with the improved survival observed in the Bt x OP treatment interaction
term after oral exposure in that after septic infection, beetles
co-exposed to OP did not have higher survival (Fig. 1A, OP PTx:BtTx).