Environmental and anthropogenic factors influencing key cabbage Lepidopteran pests in the southwestern Siberia

The lepidopteran pest community composition on cabbage (Brassica oleracea L.) as the main vegetable crop in the conditions of southwestern Siberia was presented. In 2015-2019, the dominant cabbage pests were diamondback moth (Plutella xylostella L.) and cabbage moth (Mamestra brassicae L.). The continuous application of insecticides against the cabbage pests along with climatic factors led to a change in insect species community composition. This was manifested as an increase in the number of the diamondback moth and a decrease in the abundance of other Lepidoptera species. The mean number of diamondback moths varied from 0.06 (in a year of low numbers) to 1.4 specimens per plant (in years of outbreaks), and for cabbage moth - 0.12 (2015) and 0.43 (2016), respectively. In commercial cabbage field, both egg-laying and caterpillars of Pieris brassicae L. and P. rapae L. were found as a single individual. During the years of research, we noted earlier diamondback moth and cabbage moth appearance dates in the field. More frequent diamondback moth outbreaks were observed. The period of cabbage damage by the diamondback moth lasted longer than usual during the growing seasons due to an increase in the number of insect generations in the conditions of the southwestern Siberia

The effect of silicon dioxide nanoparticles combined with entomopathogenic bacteria or fungus on the survival of Colorado potato beetle and cabbage beetles

Three types of modified silicon dioxide nanoparticles (SiO2, 10-20 nm) with additives of epoxy, silane and amino groups, used independently and in combination with the entomopathogenic bacteria Bacillus thuringiensis subsp. morrisoni and fungus Metarhizium robertsii were tested against Colorado potato beetle (Leptinotarsa decemlineata) and cabbage beetles (Phyllotreta spp.). All three nanoparticles were found to have an entomocidal effect on Colorado potato beetle larvae and crucifer flea beetles when ingested. Increased susceptibility of insects to B. thuringiensis or M. robertsii blastospores and their metabolites was shown after exposure to the modified silicon dioxide nanoparticles. The potential of modified silicon dioxide nanoparticles to enhance the efficiency of biopesticides based on the bacteria B. thuringiensis and fungi M. robertsii is considered in the paper