Water stress decreases the biocontrol efficacy of a nucleopolyhedrovirus against the fall armyworm on maize

Drought events are expected to limit crop productivity in the context of current climate change. Drought is also likely to affect multitrophic interactions such as those involving plants, phytophagous insects and their natural enemies. We designed a two-phase experiment to test the effect of water availability and fertilizer treatment on the interaction between maize, the fall armyworm and its nucleopolyhedrovirus pathogen. Low irrigation of maize plants reduced virus efficiency in armyworm control. In addition, the insects did not feed on plants with high water availability and without fertilization. We conclude that water stress and plant nutrition can affect virus performance and thereby affect the efficiency of biological control and pest management, especially as water and nutrient limitation will likely increase under climate change.