Entomopathogenic fungus \kur{Metarhizium anisopliae} is one of the most common species used in biological control against pests. The thesis is analyzing effectiveness of original strains and continuously passaged strains of \kur{M. anisopliae} through nutrient substrates and different developmental stages mealworm \kur{(Tenebrio molitor)}. For original and continuously passaged strains were also evaluated the growth and spore production at different temperatures cultivation. In this thesis was investigated the efficacy of the original strains of \kur{M. anisopliae} on selected economically important pests. Strains were tested on populations of adults Pollen beetles \kur{(Meligethes aeneus)} and Cabbage seedpod weevil \kur{(Ceutorhynchus obstrictus)} and the eggs of Colorado potato beetle \kur{(Leptinotarsa decemlineata)} in laboratory conditions. Other entomopathogenic fungi were tested on the eggs of Colorado potato beetle eggs.