Efficiency of spinosad, Bacillus thuringiensis and Trichogramma brassicae against the tomato leafminer in greenhouse.

Abstract

The objective of this study was to evaluate the efficacy of three eco-friendly control agents, either singly or in a pairwise combination, for the control of the tomato leafminer, Tuta absoluta (Meyrick) (Lep: Gelechiidae). They include the naturally derived pesticide spinosad, a commercially available formulation of Bacillus thuringiensis var. Kurstaki (Bt), and a native population of Trichogramma brassicae Bezdenko (Hym: Trichogrammatidae). Tomato plants containing the T. absoluta were treated with one of the seven following treatments in a greenhouse: (1) a single release of T. brassicae against the eggs; (2) two applications of Bt (2 kg ha^-1); (3) and (4) one application of spinosad at two rates (60 and 120 g a.i. ha^-1); (5) T. brassicae release+Bt spray; (6) T. brassicae release+spinosad spray; and (7) spinosad spray+Bt spray. The highest mortality rate was recorded for the spinosad+Bt (88.33±1.43%) and T. brassicae+spinosad (78.33±3.74%) combinations, respectively; while the lowest mortality rate was obtained through the single application of T. brassicae (31.67±4.84%). Based on our results, the Bt and spinosad seem to be suitable candidates for combination with other biological and cultural techniques towards an integrated management of the tomato leafminer.