Virulence of entomopathogenic fungi against nymphs of Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae)
DOI:
https://doi.org/10.5433/1679-0359.2011v32n4Sup1p1783Keywords:
Beauveria bassiana, Metarhizium anisopliae, Isaria sp., Pathogenicity, Biological control.Abstract
The objective of this study was to evaluate the pathogenicity and virulence of isolates of Beauveria bassiana (Unioeste 47 and Unioeste 57), Metarhizium anisopliae (Unioeste 43 and Esalq 09) and Isaria sp. (IBCB 367 a d IBCB 394) against Bemisia tabaci (Genn.) (Hemiptera: Aleyrodidae). Suspensions of the isolates (1.0 × 109 conidia/mL) were sprayed on third instar nymphs on cabbage leaves. It was performed four replications, each one with 20 insects, for each treatment. The control consisted of sterile distilled water + Tween® 80 (0.01%). The number of killed nymphs was evaluated during seven days, and then they were kept in a moist chamber. To estimate the median lethal concentration (LC50), isolates suspensions of 1.0 × 105, 1.0 × 106, 1.0 × 107, 1.0 × 108 and 1.0 × 109 conidia/mL were sprayed on third instar nymphs. The number of nymphs with confirmed mortality was evaluated. The isolates B. bassiana Unioeste 47 (84.1%) and Isaria sp. IBCB 367 (98.6%) did not differ significantly, causing the highest mortalities. However, the isolate M. anisopliae Esalq 09 caused the lower confirmed mortality (23.2%). The LC50 of the B. bassiana isolates varied from 1.8 × 105 and 4.1 × 105 conidia/mL (Unioeste 57 and Unioeste 47, respectively). Among the isolates of M. anisopliae, Esalq 09 presented the highest LC50 value (7.8 × 108 conidia/mL), whereas Unioeste 43 presents the lowest (4,3 × 105 conidia/mL). The Isaria sp. isolates presented LC50 of 2.5 × 105 and 3.1 × 105 conidia/mL (IBCB 367 and IBCB 394, respectively). Therefore, B. bassiana Unioeste 47 e Isaria sp. IBCB 367 isolates had potential to B. tabaci control and for future field studies.
Downloads
Downloads
Published
How to Cite
Issue
Section
License
Semina: Ciências Agrárias adopts the CC-BY-NC license for its publications, the copyright being held by the author, in cases of republication we recommend that authors indicate first publication in this journal.
This license allows you to copy and redistribute the material in any medium or format, remix, transform and develop the material, as long as it is not for commercial purposes. And due credit must be given to the creator.
The opinions expressed by the authors of the articles are their sole responsibility.
The magazine reserves the right to make normative, orthographic and grammatical changes to the originals in order to maintain the cultured standard of the language and the credibility of the vehicle. However, it will respect the writing style of the authors. Changes, corrections or suggestions of a conceptual nature will be sent to the authors when necessary.