OVICIDAL EFFICIENCY OF SOME BOTANICAL OILS AGAINST HATCHABILITY OF POTATO TUBER MOTH, PHTHORIMAEA OPERCULELLA EGGS AND THEIR SIDE EFFECT ON CHRYSOPERLA CARNEA UNDER LABORATORY CONDITIONS

Abstract

laboratory experiments were conducted to investigate the ovicidal effect of six plant oils {Cloves (Syzygium aromaticum), Sesame (Sesamum indicum) , Peppermint (Mentha piperta), Colocynth (Citrullus colocynthis), Marjoram (Majorana hortensis), and Orange (Citrus sinenis) } against Phthorimaea operculella eggs. And to find out the compatibility of these oils with the predator Chrysoperla carnea . Data indicated that the toxicity values of the tested oils based on LC50 values were arranged in ascending orders as follows Marjoram ˂ cloves ˂ Sesame ˂ Peppermint ˂ Orange ˂ Colocynth. Marjoram oil revealed the highest mortality % while the LC50 was (0.646 ml/L) compared to other oils. Whereas Colocynth oil was the lowest toxic oil representing the highest LC50 (3.662 ml/L). Duncan analysis categorized the tested oils into three groups according to their negative effect on egg hatchability. Marjoram & Cloves oil came in the first category, where the hatchability % recorded 10.9 and 11.5, respectively at the concentration 1%. The study also indicated that superiority predation efficiency 96.4 % with Marjoram oil treated P. operculella eggs and predator lived for 15.3 days out of 16 days. Treatment with Marjoram oil was found safe to C. carnea in comparison to others natural oils. Data indicated that Duncan analysis categorized the tested oils into different groups at the length of biochemical analysis of fatty acid, total phenols, tannis and triglycerides. In spite of Marjoram oil recorded the highest inhibition of hatchability of P. operculella eggs but recorded 1866.7 μg trioleinml. So must be used freshly extraction of Marjoram oil in IPM program. (i.e. Expire date is very important at this case). Finally, the Marjoram oil had a promise resultsagainst P. operculla eggs especially it had not passive effects against one of the most common arthropod predators (green lace wing). This is a primary study needs for more efforts to apply in suitable way and tactics in the field and store in broad scale.