Baculovirus transmission routes, mode of infection and dispersal pathways in the environment. After larvae ingest OBs while feeding on contaminated foliage a portion of the infected individuals develop lethal disease and release OBs onto the host plant where they can be transmitted to a susceptible host (red arrow). OBs on foliage are also washed by rainfall into the soil, from which they can be transported back to plants by biotic and abiotic factors (black arrows). Alternatively, insects that consume OBs but survive may continue to develop, pupate and emerge as covertly infected adults (blue arrows). These adults can disperse before laying eggs and passing the infection to their offspring. Vertical transmission can be sustain over several generations until some elicitor or stress factor triggers (orange arrow) the covert infection into lethal disease which returns to the horizontal transmission cycle (red arrows). [1]