| Abstrakt: |
The aim of the present study was to determine the species composition of the harmful and beneficial entomofauna, the dominant harmful species and their entomophages, as well as the indices of species diversity, evennes and similarity in crops of two wheat varieties (Venka 1 and Dunaviya). The observations were carried out in the period 2019-2021, in the experimental field of the IASS "Obraztsov Chiflik" - Ruse. To establish the species composition of the entomofauna, the population density of the dominant harmful species and their entomophages, the classic method − cutting with a standard sweeping net - was used. Monitoring of the entomofauna showed differences in the quantitative and qualitative composition of harmful and beneficial insects during the three years of the study in both wheat varieties. Wheat hosts insects from seven orders - Coleoptera, Diptera, Hemiptera, Homoptera, Hymenoptera, Neuroptera and Thysanoptera. The english grain aphids /Sitobion avenae L./, the barley leaf beetle /Lema melanopus L./ and the green leafhopper /Cicadella viridis L./ were identified as harmful species of economic importance in both varieties of wheat. The density of harmful entomofauna is not high (there are enough beneficial insects) and it can be concluded that the state of natural equilibrium is preserved. Biodiversity is at normal levels and the evenness index makes it possible to protect the balance elements. [ABSTRACT FROM AUTHOR] |
