Survey of natural populations of Trichogramma (Hym, Trichogrammatidae) in the vineyards of Alsace (France)

Activity of Trichogramma, assessed by trapping with host-eggs, was observed as early as April and continued until October in the vineyards and their s urrounding biotops. Trichogramma showed the greatest activity in April-May, July and September. Parasitized eggs were found before the main laying per iod of the first generation of the grapevine moths Lobesia botrana Den. and Schiff. and Eupoecilia ambiguella Hb. Four native species, Trichogramma ca coeciae Marchal, Trichogramma daunalae Dugast and Voegele, Trichogramma eva nescens Westwood and Trichogramma principium Sugonjaev and Sorokina were fo und.