Resurgence of phytophagous mites in papaya: can natural enemies provide a lasting solution to the increasing mite problem in papaya in the Americas?

Abstract: Papaya, Carica papaya, is a tropical fruit crop with 3 major key pests (fruit flies, aphids and leafhoppers) and several secondary pests, i.e., scales, mealybugs and mites, i. e., Tetranychus spp., and Eutetranychus spp. Chemical control practices aimed at controlling one of the key pests disrupt the beneficial fauna of the secondary pests, causing continuous resurgences. Through preliminary surveys and literature search, we verified that mites are now one of the major problems affecting papaya production in North and Central America (USA, Belize, Mexico). We concluded that the lack of natural enemies in these plantations was the major reason for mite severity. The first goal of the present study was to determine under Florida conditions, the efficacy and interactions of natural or resident predators, i. e., Neoseiulus longispinosus (Acari: Phytoseiidae), Neoseiulus umbraticus, Amblyseius largoensis inhabiting papaya and exotic predators, i. e., Amblyseius swirskii and Phytoseiulus persimilis. From this study we determined that the natural predator, N. longispinosus was a key predator; intraguild predation of introduced species, may affect its effectiveness. The second goal was to determine the best sampling unit to be used in the field to assess mite infestation and predator levels in papaya.