How spider mites select their food sources and perform in corn genotypes grown under different levels of irrigation

There is a commonly accepted notion that corn plants become more susceptible to spider mite infestation when grown under drought stressed conditions, but experimental studies to support this notion are lacking. We hypothesized that spider mites have the ability to distinguish drought stressed plants and use this ability so select their food sources. We tested how spider mites locate their food source, and their choice between stressed and unstressed plants using Y-tube bioassay. In addition we carried out a green house study were plants were set in block allowing plants under different levels of irrigation to be in contact, to determine spider mite choice and performance by measuring their density over time. A follow up study was conducted in a field trial were we determined spider mite densities in different corn genotypes under different levels of irrigation over time. Our studies suggested that spider mites use olfactory cues to locate or chose their food sources, and when given a choice between unstressed and slightly or stressed plants, unstressed plants are less preferred. Plant characteristics that are altered by levels of irrigation and may influence spider mites choice were analyzed.