Identification and Evaluation of Native Predators of Frankliniella occidentalis (Thysanoptera: Thripidae) in the Mediterranean

Predatory insects of Frankliniella occidentalis (Pergande) were surveyed from the summer of 1991 through the autumn of 1992 in nonsprayed vegetable and ornamental crops on the north Mediterranean coast of Spain. The predatory fauna comprised insects in 5 orders, 8 families, and 18 species. The anthocorid bugs Orius laevigatus (Fiever) and O. majusculus (Reuter) and the mirid bugs Dicyphus tamaninii Wagner and Macrolophus caliginosus Wagner were the most numerous and widely distributed species observed, constituting 95% of all predators. All 4 of these species were able to complete their nymphal development feeding on F. occidentalis nymphs. Developmental periods of both mirid bugs species was longer than that of both anthocorid bug species. Prey consumption during nymphal stages was high and similar for all 4 predator species. Adults of all 4 species consumed a higher number of F. occidentalis nymphs than did their nymphs. Fecundity and longevity were higher for both anthocorid bug species compared with both mirid bug species. The potential of all 4 species for biological control of F. occidentalis is discussed.