Timing window identified for African armyworm viral controls
Changing the time at which viral biopesticides are applied to crops provides better control of armyworms, researchers from the UK-funded Sustainable Agricultural Research for International Development (SARID) programme have discovered. They looked at the relationship between African armyworms ( Spodoptera exempta) and the parasitic baculovirus, S exempta nucleopolyhedrovirus (SpexNPV). They found that although the virus was present in all S exempta adults, and probably present in all caterpillars. Viral loads carried by adults and larvae vary considerably within and between outbreaks, notes project leader Professor Kenneth Wilson. There is a “cycling” of viral loads between the rainy season when it is high, and the dry season when it is low, he adds.