Mixed infections of type I resistant codling moth larvae in treated orchard leaves

Abstract : We have previously demonstrated the occurrence of mixed infections when susceptible codling moth larvae were allowed to feed on apple leaves sprayed with Carpovirusine EVO2. Carpovirusine EVO2 contains both CpGV-M and CpGV-R5 genotypes. Now we present the dynamics of infections on larvae carrying a type I resistance. To that aim, we collected apple leaves just after a standard treatment of Carpovirusine EVO2 on an orchard. Neonate larvae of the RGV laboratory colony that carry the type I resistance, were deposed onto the leaves and allowed to eat for selected lengths of time, then transferred to clean rearing media. The infection status was individually analyzed after 7 days by qPCR followed by High Resolution Melting. No single CpGV-M infection was observed. The probability of mixed infections increased when increasing the time of feeding on the leaves.