Felicia MURESAN and D. MUSTEA
Agricultural Research Station Turda; Agriculturil Street, 27, Turda, 3350 ROMANIA

In the regions of Transylvania favorable to maize crop, about 8-13 % of the yield is lost due to the damages caused by the European Corn borer (Ostrinia nubilalis Hbn.). At the some hybrids the yield loss may reach 21-22 %.
This damages produced by Ostrinia nubilalis on maize crop determined the application one of biological methods of central no polluting the environment and agrofeeding products contributing in echilibriurn maintaining in agroecosystems

Between 1996-1998 at Agricultural Research Station Turda was used as biological methods of this pest to control some of parasites species of Trichogramma (T. maidis, T. evanescens, T. dendrolimi), biological products (Thuringin 6000, Dipel 2x) and chitin inhibitors (Match 050 EC, Insegar 25 WP) that produce interruption of larvae transformation in pupa and from eggs to larvae.

T. maidis was proved to be the most adapted at maize crop, followed by T. evanescens  which reduced the attack frequency of borer very significantly and yield increase was about 19%.
The biological products used reduced significantly the attack of this borer and the yield increase was about 10 %.

Key words: Ostrinia nubilalis, Trichogramma spp., biological products, attack frequency, yield.