Virulência de Thyrinteina arnobia virus (TaV) e de Bacillus thuringiensis à Thyrinteina arnobia (Lepidoptera: Geometridae): efeito da temperatura no desenvolvimento das lagartas e do pH da calda de pulverização
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Data
2003-02
Autores
Colmenarez, Yelitza Coromoto [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Este estudo teve por objetivo avaliar a eficiência do Thyrinteina arnobia vírus (TaV) e de Bacillus thuringiensis quando submetidos a diferentes condições de pH e temperatura no controle da lagarta parda Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae). Foram testadas 4 temperaturas (18, 22, 26 e 30º C) e 4 pHs diferentes (5, 6, 7 e 8). Os ovos de Thyrinteina arnobia foram provenientes de uma criação em dieta artificial, mantida em laboratório. Os entomopatógenos foram aplicados em folhas de Eucalyptus grandis, para posterior oferecimento à lagartas do 3º. e 5º. instares. O ensaio de pH foi conduzido em sala climatizada (temperatura: 25 ± 1oC ; UR: 70 ± 10 % e fotofase de 13 horas), enquanto que os ensaios de temperatura os tratamentos foram conduzidos em câmaras de BOD e fotofase de 13 horas. Os experimentos foram instalados no delineamento experimental inteiramente casualizado e a distribuição dos tratamentosem esquema fatorial 4x3, com 10 repetições de 5 lagartas cada uma, sendo avaliadas 150 lagartas para cada tratamento. Os dados obtidos foram submetidos à análise de variância e as médias comparadas pelo teste t (LSD) ao nível de 5 % de probabilidade. A variável avaliada foi a mortalidade acumulada das lagartas. As observações foram feitas diariamente porém, para a análise estatística consideraram-se as avaliações realizadas aos 4, 6, 8, 10 e 15 dias. Os dados foram corrigidos utilizando-se a raiz quadrada de x + 1. No experimento sobre a influência da temperatura, foi verificado que quanto maior a temperatura, maior a mortalidade causadas pelo TaV e pelo B. thuringiensis, tanto para lagartas de 3o. instar quanto para lagartas de 5o. instar de T. arnobia. As temperaturas mais favoráveis para a expressão da ação de ambos os patógenos foi 26 e 30ºC. No experimento sobre o efeito do pH da calda de pulverização... .
The objective of this work was to evaluate the efficiency of Thyrinteina arnobia virus (TaV) and Bacillus thuringiensis when exposed to different conditions of pH and temperature to the eucalyptus brown looper control Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae). It was evaluated at 4 different temperatures (18, 22, 26 and 30ºC) and 4 different pHs (5, 6, 7 and 8). T. arnobia larvae were reared in an artificial diet and maintained in the laboratory. The entomopathogens were applied to Eucalyptus grandis leaves, and these were offered to larvae at the 3rd and 5th instars. The pH assay was conducted in a controlled conditions (temperature of 25 ± 1oC ; RH: 70 ± 10 % and photophase of 13 hours). The temperature assays were conducted at a controlled temperatures, in a BOD room with photophase of 13 hours. The experiments were installed in the following factorial analysis 4x3, with a experimental design completely randonized, with 10 replications with 5 larvae each one. The data obtained were submitted to ANOVA and means compared by t test (LSD) (P£ 0.05). The variable evaluated was the accumulative larvae death. The observations were made daily, but for the statistical analysis only the evaluations in 4, 6, 8, 10 and 15 days were considered. The temperature experiment showed that higher temperature caused higher mortality to both 3rd and 5th instars of T. arnobia larvae. The more favorable temperatures were 26ºC and 30ºC for the expression of both pathogens. The results of suspention pH experiment showed that pH 7,0 was the most adequated for the B. thuringiensis action for both instars of T. arnobia. However, the TaV action in T. arnobia larvae was not affected for the different pHs evaluated. In different experiments carried out, 3rd instar larvae were more susceptible than to 5th instar. Also for the different temperatures and of different pHs, B. thuringiensis... (Complete abstract, click electronic address below).
The objective of this work was to evaluate the efficiency of Thyrinteina arnobia virus (TaV) and Bacillus thuringiensis when exposed to different conditions of pH and temperature to the eucalyptus brown looper control Thyrinteina arnobia (Stoll, 1782) (Lepidoptera: Geometridae). It was evaluated at 4 different temperatures (18, 22, 26 and 30ºC) and 4 different pHs (5, 6, 7 and 8). T. arnobia larvae were reared in an artificial diet and maintained in the laboratory. The entomopathogens were applied to Eucalyptus grandis leaves, and these were offered to larvae at the 3rd and 5th instars. The pH assay was conducted in a controlled conditions (temperature of 25 ± 1oC ; RH: 70 ± 10 % and photophase of 13 hours). The temperature assays were conducted at a controlled temperatures, in a BOD room with photophase of 13 hours. The experiments were installed in the following factorial analysis 4x3, with a experimental design completely randonized, with 10 replications with 5 larvae each one. The data obtained were submitted to ANOVA and means compared by t test (LSD) (P£ 0.05). The variable evaluated was the accumulative larvae death. The observations were made daily, but for the statistical analysis only the evaluations in 4, 6, 8, 10 and 15 days were considered. The temperature experiment showed that higher temperature caused higher mortality to both 3rd and 5th instars of T. arnobia larvae. The more favorable temperatures were 26ºC and 30ºC for the expression of both pathogens. The results of suspention pH experiment showed that pH 7,0 was the most adequated for the B. thuringiensis action for both instars of T. arnobia. However, the TaV action in T. arnobia larvae was not affected for the different pHs evaluated. In different experiments carried out, 3rd instar larvae were more susceptible than to 5th instar. Also for the different temperatures and of different pHs, B. thuringiensis... (Complete abstract, click electronic address below).
Descrição
Palavras-chave
Lagarta, Pragas agricolas - Controle biologico, Entomologia, Biological control
Como citar
COLMENAREZ, Yelitza Coromoto. Virulência de Thyrinteina arnobia virus (TaV) e de Bacillus thuringiensis à Thyrinteina arnobia (Lepidoptera: Geometridae): efeito da temperatura no desenvolvimento das lagartas e do pH da calda de pulverização. 2003. v, 70 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Ciências Agronômicas, 2003.