Effectiveness of different bio-techniques for controlling the pin worm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae).
A study to evaluate the use of the egg-parasitoid, Trichgramma evanescens (West.) releases alone and/or in combination with certain bio-insecticides for controlling the tomato borer, Tula absoluta (Meyrick) (Lepidoptera: Gelechiidae) under field conditions was carried out at the experimental farm of the Environmental Studies and Research Institute, Sadat City University, Minufiya Governorate, Egypt during 2013 and 2014 tomato growing summer plantation. Results indicated that early practices, at seedling stage, of the tested control techniques achieved highest potential, best foliage and fruit protection, and played a vital role for suppression T. absoluta damage comparing to the same applications at either flowering or fruiting stages. Results revealed significant and positive efficacy by practicing 12 releases of T. evanescens (at the rate of 80.000 parasitoid/fed.) at seedling stage, which reduced the damage at both foliage and fruiting stages by the lowest mean numbers (1.31±0.195, 1.51±0.027, 0.4±0.018 and 0.43±0.018) and (1.06±0.098, 1.39±0.027, 0.37±0.015 and 0.31±0.012) of infested leaves, mines/leaf, surviving larvae and infested stems in both seasons, respectively. Also, a significant fruit reduction (0.70±0.012 and 0.61±0.015) was recorded at seasons 2013 and 2014, respectively. On the other hand, this treatment gave the lowest mean values (53.89±0.36 and 50.66±0.61 kg/ton) of loss of fruit infestation relative to the highest healthy fruit yield (10.18±0.023 and 10.5±0.02 ton/fed) in both seasons, respectively. Also, obtained results indicated that the technique of 4 releases of Trichogramma+4 applications of Protecto+Spinosad bait performed the best efficiency plant protection comparing to other tested treatments practiced at both flowering and fruiting stages in both seasons.