Title: Controle microbiano da traça-da-batata, Phthorimaea operculella (Zeller, 1873) (Lepidoptera:Gelechiidae), com granulovírus
Abstract: Different aspects of a Brazilian granulovirus strain, PhopGV, isolated from the potato tuber moth Phthorimaea operculella were investigated with the purpose to reveal the biological control potential of this pathogen and perspectives for in vivo production.The relationship of larval mortality-virus concentration for P. operculella was determined at different temperatures on potato leaves and tubers.Virulence of PhopGV to P. operculella was not affected by temperatures from 18 to 30°C.Larvae treated on foliage proved to be less susceptible to PhopGV than larvae treated on tubers.The maximum yields of infected larvae were similar at 18, 24 and 30 °C (32.0, 31.4 and 34.8%, respectively) and these yields were achieved by the optimal virus concentrations of 41, 6.3 and 62 x 10 5 OB.mL -1 .Consequently, the amount of virus inoculum to generate similar yields of infected larvae was much lower at 24 °C than at 18 and 30 °C.However, the time until harvest the infected larvae was longer at 18 °C and shorter at 30 °C than at 24 °C.The total haemocytes count for last instar healthy larvae were 2.5-fold higher than the infected larvae.The virus persisted viable on tubers under storage conditions for at least to 60 days post-treatment resulting in mortality above 80%.The pathogen was also highly virulence to the tomato pinworm Tuta absoluta, causing high mortality, delayed larval growth and inhibited pupation of infected larvae.This Brazilian PhopGV strain has potential to control PTM larvae on potato tubers at a broad range of temperature.