Título:	Ecologia do gafanhoto stiphra robusta (Orthoptera : Proscopiidae) e seu controle biológico com o fungo entomopatogênico metarhizium flavoviride (hyphomycetes)
Outros títulos:	Ecology of the grasshopper Stiphra robusta (Orthoptera:Proscopiidae) and its biological control with the entomopathogenic fungus Metarhizium flavoviride(Hyphomycetes)
Autor(es):	Vicentini, Sérgio
Orientador(es):	Raw, Anthony
Assunto:	Fungos - agentes no controle biológico de pragas Controle biológico Gafanhoto
Data de publicação:	19-Mai-2020
Data de defesa:	1999
Referência:	VICENTINI, Sérgio. Ecologia do gafanhoto stiphra robusta (Orthoptera: Proscopiidae) e seu controle biológico com o fungo entomopatogênico metarhizium flavoviride (hyphomycetes). 1999. 138 f., il. Tese (Doutorado em Ecologia)—Universidade de Brasília, Brasília, 1999.
Abstract:	Considering diverse environmental pollution problems registered in Brazil and other countries due to use of chemicals in agriculture and livestock, the development of new pest control strategies is necessary, and biological control has emerged as an alternative. Following isolation of the entomopathogenic fungus Metarhizium flavoviride from cadavers of the grasshopper Schistocerca pallens (Orthoptera: Acrididae) it was possible to extend studies on biological control to other grasshopper pests, such as Stiphra robusta, the target of this work. In order to do that, reproduction and development of this insect were analyzed as well as the feasibility of using the fungus M. flavoviride. After collecting egg pods in the field, laboratory studies were initiated by determining the ideal deep for egg incubation in sandy soil. Incubations between 11 and 5 cm resulted in hatching rates varying from 95% to 97%, respectively. At 3 and 1 cm, hatching was only 74% and 23%. For eggs collected in the field, deeps from 11 to 5 cm led to incubation periods varying from 36 to 37 days, whereas it varied from 40 to 69 days at 3 and 1 cm. Eggs obtained at laboratory conditions needed a larger incubation period, varying from 87 to 93 days at 11 and 5 cm. At 3 and 1 cm, incubation period was 123 and 177 days. Eggs showed a high viability, resulting in approximately 97% nymphs and, from those, 92% reached the adult stage. However, storage under laboratory conditions of eggs in dried soil affected their longevity as time passed by. Reproduction capacity studies in the laboratory, revealed that females lay a minimum of 5 egg pods and a maximum of 8, and a total of 155 to 535 eggs are obtained per female. Following emergence, insects went through 7 nymphal instars, taking up to 106 days to reach the adult stage, with a life cycle from 7 to 8 months. Infection rates up to 100% were observed at 27°C and 32°C, with mortality onset at the fifth day. However, at 17°C and 22°C, there was a reduction in infection rates to 25% and 83%, respectively. Performance of M. flavoviride was affected by environmental factors, and mortality onset varied from 3 days in the treatment without conidial exposition to 11 days in treatment in which conidia were exposed during 4 days, after which mortality was no longer recorded. Better results were obtained when conidia were applied during the days (91%), in comparison to night applications (4.7%). This difference resulted in 55.6% and 3.94% of leaf consumption between day and night applications, respectively. Food consumption was reduced following fungal application (from 64% to 48%), and leaf ingestion was not observed from day 4th on. After 4 days exposure of conidia under field conditions, infection rate dropped from 83% to 57%.
Unidade Acadêmica:	Instituto de Ciências Biológicas (IB)
Informações adicionais:	Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Ecologia, 1999.
Programa de pós-graduação:	Programa de Pós-Graduação em Ecologia
Agência financiadora:	Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq).
Aparece nas coleções:	Teses, dissertações e produtos pós-doutorado

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