The effects of water-stress, temperature, and plant traits on the outbreak potential of a specialist and generalist spider mite species (Acari: Tetranychidae)

The host-generalist two-spotted spider mite [Tetranychus urticae (Acari: Tetranychidae); TSM] and host-specialist Banks grass mite [Oligonychus pratensis (Acari: Tetranychidae); BGM] are common pests of corn (Zea mays L.) in the arid western United States. Climate warming and decreased precipitation may promote conditions favored by these spider mites. However, rapid evolution of spider mite resistance to commercially available acaricides is driving the need for alternative solutions for managing outbreaks. Planting of drought-tolerant corn hybrids has been proposed to be a dual-purpose strategy for mitigating water deficits for irrigation and reducing leaf conditions favorable for BGM outbreaks. However, understanding of the mechanisms responsible for reducing the BGM in the field is lacking, and determining whether outbreaks of the TSM can also be averted using drought-tolerant corn is a pressing concern. We conducted a two-year field study testing a drought-tolerant corn hybrid and a...