Data on prevalence, biological and physiological characteristics of the diamondback moth Plutella xylostella (Lepidoptera: Plutellidae) are presented. Pest damage is described. Reasons causing increase in harmfulness and economic importance of the insect are noted. An increase in the number of generations able to develop during growing season and earlier pest emergence are recorded under conditions of Siberian region. Factors contributing to the insect density dynamics, including plant species and variety, entomophagous arthropods and entomopathogenic microorganisms, have been considered. Range of chemical insecticides recommended for diamondback moth management in Russian Federation has been indicated. An increase in resistance to chemicals and certain entomopathogens in P. xylostella populations in different regions of the world has been recorded. Possibility of pheromone traps exploitation for efficient pest detection and monitoring has been established. Perspectives of novel efficient and safe means of pest density regulation have been defined.
Experiments on three varieties of Brassica oleracea (white cabbage, red cabbage, and cauliflower) were conducted during the years 2008-2011 in Western Siberia (Russia) to study the influence of host plant on herbivore infestation. The results revealed the evidence of different infestation of white cabbage, red cabbage, and cauliflower by the common herbivores in Western Siberia. Flea beetles as the earliest herbivores preferred to infest white cabbage. Contrary to those herbivores, M. brassicae and P. xylostella larvae infested red cabbage most of all. The latest herbivore of all plants studied, P. brassicae, preferred cauliflower but not red cabbage. The possible contribution of some factors in summary effects observed in the study was discussed. Further studies are being planned in which tritrophic interaction including B. oleracea plant, herbivore, and microbial insecticides should be investigated. These studies will help to develop biological insect control on Brassica oleracea crops in order to supply ecologically safe plant protection.
The article presents the results of the study of growth-stimulating and antifungal activity of strainsBacillus thuringiensisssp.fukuokaensisssp.morrisoni, ssp.toumanoffi, ssp.dakotaand ssp.amagiensis. The positive effect of all studied strains on morphometric parameters of spring rape and spring wheat seedlings was revealed. Treatment of spring rape seeds with spore-crystal mixtures ofB. thuringiensiscontributed to a significant increase in the length of roots by 1.93.4 times and sprouts – by 1.3-1.9 times, depending on the strain. Stimulation of plant growth was also observed in the inoculation of spring wheat seeds with suspension strains ofB. thuringiensis. However, a significant positive effect was revealed only in the variant with the use of the strain ofB. thuringiensisssp.fukuokaensis. There was a downward trend in the number of spring wheat seedlings affected with root rot when the seeds were treated with the strains ofB. thuringiensisssp.morrisoni,ssp.dakota,ssp.amagiensis. In the experiments with pure cultures it was found that all tested strains ofB. thuringiensisshowed a high degree of antagonistic activity to two types of phytopathogens. The inhibitory activity of the strains ofB. thuringiensison the 10th day of the experiment with regard toFusarium oxysporumranged from 68 to 83%,Alternaria alternata– from 71 to 89%. The analysis showed that all studied strains ofB. thuringiensisstimulated the growth of plants of spring rape and spring wheat and showed antifungal activity. The obtained data are of interest for further research in order to create multifunctional biological preparations for plant protection.
Due to the growing variety of vegetables, the impact of genotypic parameters of plants on pest resistance and efficiency of biological specimens is of high importance when selecting and creating new varieties and hybrids. The researchers found out the significant differences in stability of parental forms, hybrids and cucumber varieties of the Siberian selection in relation to twospotted spider mite. The paper finds out relatively resistant parental forms - ZhL-4 and GP-61/b, and also samples of the paternal form - GF-7 and a maternal line - ZhL-9 damaged by a phytophage in a strong degree have been defined rather steady against a phytophage. High acaricidal effect of Phytoverm was found on all studied varietal samples, however the most effective biospecimen restrained development of the pest on plants of relatively resistant to phytophage of female line ZL-4. Reproduction of the twospotted spider phytoseiulus did not depend on genotypic features of parental forms, varieties and hybrids of cucumbers. The number of acarifages increased by 7.8-8.2 times in two weeks after appearance on the plants inhabited by spider mite in comparison with the initial number, as a result of which the damage rate of plants by the pest of most cultivars decreased, and in male forms practically did not change (GF-19) or slightly increased (GF-7). According to biochemical parameters, cucumber varieties with different degree of resistance to phytophage differed in dry matter content. Non-resistant to twospotted spider mite female forms LL-9, LL-12/1 and Nadezhda variety contained the lowest concentration of dry matter (5.4%), the highest amount of dry matter was observed in female line LL-4, which has the highest pest resistance (6.0%). Since the inherited traits are predominantly transmitted by the maternal component and the paternal form enhances these properties, it is important to assess not only the yield and flavour qualities but also the degree of resistance of parental forms to pests when selecting cucumber varieties and hybrids.
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