and morphological data related ofresistance and susceptibility to diseases is important when selecting hybrids for commercial and scientificinterest. This study analyzed the cytopathology of B. mori trachea to BmNPV, isolated geographicallyin Paraná state, Brazil. Fifth instar larvae were divided into two groups, control and inoculated; theviral suspension used was 2.4 × 107polyhedral occlusion bodies/mL. From the second to the ninth daypost-inoculation, segments of silkworm organs, containing the trachea, were processed for transmissionelectron microscopy. Analyses of fresh hemolymph were also performed to verify the susceptibility of