Exploring the impact of a chemical disinfectant and an antiviral drug for RNA virus management in the Mediterranean fruit fly mass-rearing

The Mediterranean fruit fly is an agricultural pest of a wide variety of fruit crops. An effective method to counteract them in the field is through the application of the sterile insect technique, which requires the mass-production of sterile males. The presence of pathogens, and specifically viruses, threatens the well-being of mass-reared insects generating an interest on the development of strategies for viral elimination or containment. Thirteen RNA viruses have been described in the medfly although so far only one of them, Ceratitis capitata nora virus, has been associated with detrimental effects on medfly development. In this context, medfly larvae were supplied with a chemical compound (formaldehyde) and an antiviral compound (ribavirin) via oral feeding to (1) test the potential of these compounds for viral elimination and (2) analyze their effect on medfly development. Overall, formaldehyde treatment did not reduce the viral titer for any of the tested viruses, while ribavirin effectively reduced the levels of two widespread RNA viruses but not in a dose–response manner. However, the addition of both compounds correlated with detrimental effects on medfly fitness, arguing against their use in mass-rearing facilities.