Programa de Pós-Graduação em Agronomia

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Navegando Programa de Pós-Graduação em Agronomia por Autor "Andrade, Nathália Costalonga"

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    Bases biológicas de Trichogramma pretiosum (Riley, 1879) (Hymenoptera: trichogrammatidae) e nematoides entomopatogênicos sobre Rachiplusia nu (Guenée, 1852) (Lepidoptera: noctuidae) na cultura da soja
    (Universidade Estadual do Norte do Paraná, 2024) Andrade, Nathália Costalonga; Bueno, Adeney de Freitas; https://orcid.org/0000-0002-5462-5845; http://lattes.cnpq.br/7329418125245335; Alves, Viviane Sandra; https://orcid.org/0000-0003-2381-8115; http://lattes.cnpq.br/3794580975938452; Silva, Gabriela Vieira; https://orcid.org/0000-0002-6432-0391; http://lattes.cnpq.br/6593862082231188; Carvalho, Vanessa Andalo Mendes de; https://orcid.org/0000-0002-6310-1680; http://lattes.cnpq.br/8132224406035792; Bueno, Adeney de Freitas; https://orcid.org/0000-0002-5462-5845; http://lattes.cnpq.br/7329418125245335
    Brazil is considered the world's largest producer of soybeans (Glycine max) and has high levels of use of Bt soybeans, which provide control over various caterpillars that attack this crop, such as the species Rachiplusia nu (Guenée, 1852) (Lepidoptera: Noctuidae). However, the occurrence of this species has been reported in some Brazilian states on Bt soybeans (Cry1Ac), which may indicate resistance, increasing its importance as a pest insect. Therefore, the aim of this work was to evaluate the biological bases of Trichogramma pretiosum Riley, 1879 (Hymenoptera: Trichogrammatidae) and entomopathogenic nematodes (NEP) of the genera Heterorhabditis and Steinernema with a view to controlling R. nu, separately. To this end, tests were carried out with the parasitoid T. pretiosum to assess its biological characteristics and parasitism capacity on R. nu eggs at temperatures of 20, 25 and 30ºC. The parameters evaluated in the biology tests were: duration of development (egg-adult); percentage of emergence (viability); number of individuals per egg and sex ratio. The parasitism capacity was also assessed at the same temperatures, and the following biological parameters were observed: number of eggs parasitized daily; cumulative percentage of parasitism; total number of eggs parasitized per female and female longevity. For the NEP, experiments were carried out on the selection of isolates (pathogenicity and virulence), the efficiency of different concentrations (0, 25, 50, 75 and 100 IJ/cm²) and tests on production (total production, production per caterpillar, production per gram of R. nu caterpillar). As for the data on parasitoid action, in the experiments on biology, the parameters percentage emergence and number of parasitoids per egg were not affected by the conditions studied. As for the sex ratio, the results obtained at 25 and 30ºC and the duration of development (egg-adult) showed differences between the three temperatures. In the capacity bioassays, the parasitism rate of T. pretiosum was directly influenced by temperature, and longevity was greater as the temperature decreased, while the accumulated percentage of parasitism varied from 6 to 10 days, from the highest temperature to the lowest, respectively. The highest number of parasitized eggs was 46 eggs per female. As a result of the NEP selection, isolates UEL07 and UENP06 were selected, both Heterorhabditis amazonensis, which showed 100% mortality in R. nu. At all concentrations, the nematodes were pathogenic on R. nu, with results of 98 to 100% mortality at the highest concentration used for isolates UENP06 and UEL07, respectively. Finally, the average total production of NEP was 2.9 × 10⁴ for UENP06 and 3.9 × 10⁴ for UEL07.