EVALUATION OF SOME PLANT EXTRACTS AND BACTERIA FOR CONTROLLINC THE CUTWORM AGROTIS IPSILON<Hufn> (LEPIDOPTERA)

Abstract

The extracts of Piper nigrum fruits, Lupinus termis seeds, Melia azedaraclt leaves and Allium sativum globes were evaluated against 1st, 2nd and 4th instar larvae of Agrotis ipsilon. Ethanol benzene and water were used as solvents to make one extract. Two kinds of bacteria (Cry 1(C) and Cry I (A) of Bacillus thuringiensis) were also evaluated against the same larval instars. The mixtures of LC50 's of each plant extracts and each kind of bacteria were also tested. The obtained results indicated that the Piper nigrum was the most effective extract while the Allium sativum was the lowest one. Data showed that Cry I (C) gave more effect than Cry 1 (A). In addition, Piper nigrum extract gave the highest mortality when combined with Cry I (C) or Cry I (A) of Bacillus tlturingiensis. Lupinus tennis extract affected on larval mortality more than Melia azedarach extract but when mixed with bacteria, Melia azedaraclt became the most effective. Fecundity and productivity of Agrotis ipsiloti moths resulted from treated 1st, 2nd and 4th instar larvae with LC50•s of Piper nigrum extract, Ccy I (C) of Bacillus thuringiensis and their mixtures were significantly affected on oviposition. The oviposition period was reduced while the pre- and post­ oviposition periods prolonged. Also, the data showed reduction in the number of eggs per female and hatchability percentages. Microscopically examination showed signs of deformities where the cells of mid gut of the 4th instar larvae were affected after treatment with LC50's of Pipet nigrilni extract, Cry I (C) of B.t. and their mixtures. The treated larvae showed a great disintegration of the epithelium, vacuolization and separation of the peritrophic membrane.

Kev words: Black cutworm - Agrotis ipsilon - Plant extracts -Bacteria - Histopathology