Hidden infections, hidden impacts: Covert viral infections in a lepidopteran host

Summary

Insect viral infections are ubiquitous in nature. These infections can be classified in overt and covert infections. While the former induce clear symptoms of disease, often leading to host death, covert infections do not cause major visible symptoms and are vertically transmitted from their “healthy looking” parents to their offspring. Additionally, covert infections may revert to the overt state following the exposure of the insect population to a stressor (e.g. overcrowding).
Given their asymptomatic nature, these infections represent a burden for insect mass rearing applications (e.g. insects for food and feed industries), leading to substantial economic losses once they revert to the overt state. Despite this, covert viral infections are still largely unexplored. Therefore, this PhD project aimed at gaining a deeper understanding of the molecular mechanisms underpinning the relationship between the host Spodoptera exigua (beet armyworm) and its covertly infecting RNA (Family: Iflaviridae) and DNA (Family: Baculoviridae) viruses.