ABSTRACT
The presence of Sitophilus zeamais causes damages through severe weight reduction, depreciation of commercial value of the product and reduction of its nutritional value, also acting as a disseminator of fungus, favouring the deterioration of stored product, causing the increase of moistness and temperature of mass of grains, due to the insects, metabolism. The present work was aimed at evaluating the effects of irradiated aqueous, hexanic and ethanolic extractsof Solanum paniculatum, Dahlia pinnata, Pennisetum purpureum, Allamanda cathartica, Dieffenbachia brasiliensis, Lavandula angustifolia, Rhododendron simsii, Annona squamosa, Agave angustifolia, Ocimum basilicum, Coffea arabica and Hibiscus rosa-sinensis, in order to identify new substances for integrated pest management (IPM) of pests and to observe possible effects of gamma radiation such as the increase, reduction, activation and inactivation of natural products to control pests. The effect of contact in adults of S. zeamais t was evaluated. An experimental irradiator of Cobalt-60, model Gammacell 220 was used for the irradiation. The vegetal extracts were exposed to doses of 2.5; 5.0; 7.5 e 10.0 kGy, in environment temperature. The best results were obtained with aqueous extract at 10.0 kGy and ethanolic extract at 5.0 kGy of H. rosa-sinensis, which showed 30.0 and 32.0 of efficiency respectively. The aqueous extract and hexanic of C. Arabica at a dose of 5.0 kGy showed 42.0 of efficiency, differing statistically from the others. The extracts of O. basilicum presented efficiency between 30.0 and 44.0. According to the results we verified that the gamma radiation interferred on behavior of natural products for pest control and it can result in increase, reduction, activation and inactivation of the same.
KEY WORDS:
Sitophilus zeamais; gamma radiation; control; extracts; natural products.