Examinando por Materia "Bacillus thuringiensis"

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Biological cycle and comparative study of bioinsecticide efficiency on the Heliothis virescens (Lepidoptera:Noctuidae) borer in blueberry cultivation
(Universidad Nacional José Faustino Sánchez Carrión, 2023-07-20) Velásquez Ochoa, Edwin Ricardo; Quiliche Duran, Jean Piere Jesús
Objectives: To determine the biological cycle of H. virescens and the comparative efficiency of bioinsecticides of Bacillus thuringiensis (Bt) (native strain) with respect to Bt (Kurstaki strain) and nuclear polyhedrosis virus (NPV), on fifth instar larvae. Methodology: Postures and larvae of H. virescens were collected from agricultural farms in Huaral (Lima) and reared in the laboratory. The Bt and NPV strains were applied to fifth instar larvae under field conditions, evaluating larval mortality at 72 hours using Tukey's test with the Infostat software. Results: It was found that the life cycle of H. virescens was 77.78 ± 9.14 days with complete metamorphosis. Larval mortality was statistically similar (p> 0.05) with native Bt and Bt Kurstaki treatments, and NPV application outperformed (p< 0.05) both Bt treatments in fifth instar larval mortality. Conclusion: The life cycle of Heliothis virescens in blueberries has a complete metamorphosis with six larval stages ranging from 59-88 days and better control of fifth-instar larvae was obtained with NPV.
Efficiency of entomopathogenic bacteria and fungi on Oligonychus yothersi in vitro and on Persea americana Mill. plants
(Facultad de Agronomía de la Universidad del Zulia,, 2023-11-03) Parco Quinchori, Jhimy Andy; Valverde Rodriguez, Agustina; Cornejo, Antonio; Briceño, Henry; Barrionuevo, Laura; Romero, Javier
In the germplasm bank of 22 varieties of avocado (Persea Americana Mill.) belonging to the Fruit Horticultural Institute Investigation, HermilioValdizan National University (UNHEVAL)-Peru, it is common to observe a high population of the species Oligonychusyothersi, a phytophagous mite harmful to the crop. Controls with commercial acaricides are restricted in place, due to the presence of beehives installed in adjacent plots. The objective of this study was to evaluate the effect of four commercial formulations containing strains of Metarhiziumanisopliae and Beauveria bassiana and the toxins of Bacillussubtilis, Bacillus thuringiensis var.kurstaki (Btk) for the control of O. yothersi. The entomopathogenic products were evaluated in the field applying a randomized complete block design with five treatments and three replicates. In the laboratory, 500 adult mites were selected, placing 100 mites per Petri dish with three repetitions per treatment. It was found that the formulation Bacillus thuringiensis var.kurstaki under field conditions reduced the population incidence of mites by up to 98.07% in 49 days. In the laboratory, the B. subtilis and M. anisopliae formulations caused 100% mortality six days after application proving to be efficient control alternatives.