الفهرس | Only 14 pages are availabe for public view |
Abstract Toxicity of eight plant extracts namely; Ficus nitida, Vinca rosea, Hibiscus mutabilis, Ficus elastic var decora, Bignonia purpura, Nerium oleander, Nephrolepis bostoniensis and Zinnia elegans were tested against Tetranychus urticae Koch and the phytoseiid mite Euseius scutalis (Athias & Henriot), as a widespread predatory mite associated with this pest. Vinca rosea and Nerium oleander MeoH were the most potent to T. urticae. The LC50 values were 184.19 and 213.42 ppm, respectively. On the other hand, the LC90 values were 953.28 and 1294.7 ppm, respectively. The other six plant extracts were less toxic. The LC50 of Vinca rosea and Nerium oleander against E. scutalis were 588.55 and 745.34 ppm, and the LC90 values were 3742.2 and 6555.75 ppm, respectively. Adult longevity, oviposition period, egg hatchability and the number of deposited eggs of T. urticae were decreased when treated with LC25 and LC50 concentration of Vinca rosea extract. Meanwhile, the incubation, pre-oviposition and generation periods were prolonged for treated females. Treatment of females with the LC25 and LC50 concentration of Nerium oleander MeoH extracts affected on the biology of T. urticae as follow; adult longevity, oviposition period, egg hatchability and the number of deposited eggs were decreased. On the other hand, the ABSTRACT incubation and pre-oviposition periods were prolonged for treated females. The generation period of Nerium oleander was non significant compared with control. Vinca rosea and Nerium oleander MeoH extract had mild effect on the life cycle of E. scutalis adult females. Key words: Plant extracts - Vinca rosea - Nerium oleander – Tetranychus urticae Koch – Euseius scutalis Athias & Henriot . |