From the dual cyclone harvest performance of single conidium powder to the effect of Metarhizium anisopliae on the management of Thaumastocoris peregrinus (Hemiptera: Thaumastocoridae)

PLoS One. 2023 Mar 27;18(3):e0283543. doi: 10.1371/journal.pone.0283543. eCollection 2023.

Abstract

Insect pests introduced in eucalyptus plantations in Brazil are mostly of Australian origin, but native microorganisms have potential for their management. High quality biopesticide production based on entomopathogenic fungi depends on adequate technologies. The objective of this study was to evaluate Mycoharvester® equipment to harvest and separating particles to obtain pure Metarhizium anisopliae conidia to manage Thaumastocoris peregrinus Carpintero & Dellapé, 2006 (Hemiptera: Thaumastocoridae). The Mycoharvester® version 5b harvested and separated M. anisopliae spores. The pure conidia were suspended in Tween 80® (0.1%) and calibrated to the concentrations of 1 x 106, 107, 108 and 109 conidia/ml to evaluate the pathogenicity, lethal concentration 50 and 90 (LC50, LC90) and lethal time 50 and 90 (LT50, LT90) of this fungus to T. peregrinus. This equipment harvested 85% of the conidia from rice, with production of 4.8 ± 0.38 x 109 conidia/g dry mass of substrate + fungus. The water content of 6.36% of the single spore powder (pure conidia) separated by the Mycoharvester® was lower than that of the agglomerated product. The product harvested at the concentrations of 108 and 109 conidia/ml caused high mortality to T. peregrinus third instar nymphs and adults. The separation of conidia produced by solid-state fermentation with the Mycoharvester® is an important step toward optimizing the fungal production system of pure conidia, and to formulate biopesticides for insect pest management.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Australia
  • Cyclonic Storms*
  • Heteroptera* / microbiology
  • Metarhizium*
  • Pest Control, Biological
  • Powders
  • Spores, Fungal

Substances

  • Powders

Grants and funding

Funding was provided by the following Brazilian institutions: “Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)”, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brazil (CAPES) granted the the scholarship in Germany (Financing Code 88881.134760/2016-01) and in Brazil (Financing Code 001) to S.G.M.V. and Programa Cooperativo sobre Proteção Florestal/PROTEF do Instituto de Pesquisas e Estudos Florestais/IPEF. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.