چکیده (انگلیسی):

This study investigated the effects of some essential oils on Limantria dispar (Lepi-doptera: Lymantridae, gypsy moth) larvae, one of the most serious pests of cork oak forests. The es-sential oils were first formulated as oil in water (o/w) emulsions and used in laboratory bioassays to assess their lethal concentration (LC50). Microcap-sules containing the most promising oils (Rosmari-nus officinalis and Thymus herba-barona) were then prepared by a phase separation process, followed by freeze-drying. The formulations thus obtained, characterized in terms of essential oil content and composition, morphology, storage stability, and re-lease profile, were tested on gypsy moth larvae. The results showed that the tested oils possess interest-ing larvicidal effects that make them suitable for application in integrated control strategies. The mi-croencapsulation process gave high encapsulation yields (over 98%) with both essential oils, which have different chemical compositions. The micro-capsules had toxic effects at a concentration similar to that usually employed for localized treatments with microgranular synthetic pesticides. Toxicity appeared to be maximized when the microparticles adhered to the typical hair structures of several de-foliator families. These formulations seem to be able to protect the core material against environ-mental agents and could be considered for use in controlled drug release systems. The natural active principles they contain could provide an alternative system in insect pest control.