Spider mites inhibit russet mite population growth. Russet mite population size (number of mites/plant; + SE) on wild-type (WT) (cv. CM) and def-1 plants that had been infested with russet mites alone (RM) or co-infested with spider mites (Both mites) 14 days after infestation with RM. Plants had been infested with RM for seven days when SM was introduced. Values represent the mean of 13 to 15 plants. Asterisks represent significant differences as determined by Student t-test (*, P <0.05; **, P <0.01). SE, standard error.