EN
Using of several biocenotic indexes (relative abundance, frequency, Shannon-Weaver's and Cody's formulas) in relation to the ecological analysis of aphid parasitoid guilds is discussed. The comparative ecological analysis of aphid parasitoid guilds based on Shannon's formula is demonstrated. With the use of the proposed methods we can search for reservoirs (habitats, plant species) and alternative hosts (aphid species of noneconomical importance) of beneficial aphid parasitoids in an agricultural landscape.