Biological method of struggle against the basic wreckers of the sweet corn in Republic of Moldova

Abstract

Every year, the demand of ecological products in the world is increasing more and more. Republic of Moldova also aspires to expand the areas of agricultural crops to get production with the "ecological" status. The sweet corn, is one of these cultures and every year the areas increase. However, because of the considerable develop of harmful insects on cultural fields, the damage reaches up to 15-20 % and more it is necessary to take measures of struggle. One of these, is a biological method and in this case it has appeared effective. For the period of sweet corn cultivation, excepting for the technology observance of cultivation of the given culture, there have been used biological methods of struggle against harmful insects. Depending on climatic conditions of each zone of the country where it is grown up this culture, different species of harmful insects develop. In R. Moldova, begining with year 2000, have been registered the following harmful species of insects on sweet corn: Aphis spp. (Aphididae); Agrotis spp. (Elateridae); Blaps halophila Fisch. (Tenebrionidae); Phylotreta spp. (Chrysomelidae); Helicoverpa armigera Hubner (Noctuidae) Ostrinia nubilalis Hb. (Pyraustidae). The constant useful fauna which develops due to these harmful species is: nabis spp. (Miridae); Chrysopa spp., (Chrysopidae); Coccinella spp. (Coccinelidae) and others. That is why, annually are let out individuals from species Trichogramma evanescens W., to reduce the number of harmful species H. armigera Hubner. This species annually damages on different cultures, including on sweet corn. The results on released trichogrammas in 2005, for struggle against harmful species H. armigera Hubner, are presented in this work.