Microbial control of the tomato leaf-miner, Tuta absoluta (Povolny) (Lepidoptera: Gelechiidae) by biopesticides in relation to some biological parameters.
The tomato leaf miner, Tufa absoluta (Povolny) (Lepidoptera: Gelechiidae) was treated as newly hatched and 3rd instar larvae by two biopesticide formulations; Protecto and Biover as well by the mixture of both to evaluate their toxicities to the pest. Biological and life table parameters of T. absoluta were reported when treated as newly hatched larvae by LC50s of the biopesticides. Obtained results showed that Protecto was the much effective compound used, followed by Biover and then the mixture. The later mixture gave antagonistic effect against the pest. Newly hatched larvae were more susceptible than 3rd instar larvae. Larval and pupal durations, adult longevity, post ovipositional period and life cycle of T. absoluta were increased when treated by LC50s, except for the mixture treatment. Percentages of larval mortality and sterility were decreased in all treatments. The biopesticides had decreasing effects on egg laying rate, egg hatchability, pupation, percentages of adult emergence ovipositional period and fecundity compared with the control. On the other hand, the life table parameters of T. absoluta under biocides treatments were affected. The progeny/female (Mx) and survival rate (Lx) of T. absoluta were decreased, especially in case of Protecto. Also, the biopesticides treatments decreased the net reproductive rate (Ro), increase rate (intrinsic rate of natural increase (rm) and finite rate of increase (erm)), compared with the control. Vice versa, Protecto, followed by Biover increased the time of generation (T) and doubling time (DT).