Management of Tuta absoluta in tomato by mass trapping

Management of the South American tomato leafminer, Tuta absoluta, with insecticides has led to widespread development of resistance. Mass trapping using traps baited with the female-produced sex pheromone is an attractive alternative method of management of this pest. The current study evaluated several commercial trap designs for capture of T. absoluta. Based on its small size and ease of handlng, the most effective trap is a small plastic container with entry windows cut on the sides and filled with motor oil over water. These traps are most effective when placed near ground level. Tests of septa containing 0.1 mg to 2 mg of the pheromone (95:5) E4, Z8-14Ac:E4, Z8, Z11-14Ac revealed that lower loadings were more attractive during the first week of use, but higher loadings were more attractive after 9 weeks. Ideal trap baits were loaded with 0.5 mg of pheromone. Higher numbers of T. absoluta were captured near upwind borders of tomato fields suggesting that treatments against T. absoluta should be concentrated near upwind parts of fields. Trapping in harvested and dried tomato plants revealed significant numbers of males suggesting post-harvest sanitation is very important.  Comparisons of conventional insecticide treatment versus mass trapping to lower T. absoluta damage in three different test sites showed that even when initial captures in monitoring traps were high (>35 males/trap/day), mass trapping at 48 traps/ha reduced leaf damage more efficiently than conventional insecticide treatment. Based on the typical insecticide recommendations against T. absoluta, mass trapping is an economically viable alternative.