Biological control of vegetable pests: from greenhouse to open field

The broad mite Polyphagotarsonemus latus, the spider mites Tetranychus urticae and T. evansi, and the whitefly, Bemisia tabaci, are serious pests of pepper and eggplant in Florida and elsewhere. Biological control of these and other pests pests using predaceous mites is commonly practiced in greenhouse vegetable production. Amblyseius cucumeris is used for broad mite and thrips control, A. californicus for broad mites and spider mites and A. swirskii for broad mite, whitefly and thrips. However, there is little information on the use of these predaceous mites in open field pepper and eggplant production in Florida. We evaluated A. cucumeris and A. swirskii in eggplant and ‘Serrano’ pepper in experimental plots in southwest Florida. Both mites provided significant levels of control of broad mite on both crops, although A. swirskii required fewer releases and provided better control when both mites were compared directly. In addition, A. swirskii controlled B. tabaci which is an especially important pest of eggplant in this region. Both pepper and eggplant receiving A. swirskii in 2007 yielded significantly more fruit than untreated plants or even eggplants receiving two acaricide sprays. However, A. swirskii did not provide adequate control of the spider mites Tetranychus spp, important pests of this crop in south Florida. Therefore, a mixture of A. swirskii and A. californicus was tested in eggplant. Preliminary data indicated persistence of both mites well into the crop cycle when released at planting with consequent suppression of all three pests.