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

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 (R) equipment to harvest and separating particles to obtain pure Metarhizium anisopliae conidia to manage Thaumastocoris peregrinus Carpintero & Dellape, 2006 (Hemiptera: Thaumastocoridae). The Mycoharvester (R) version 5b harvested and separated M. anisopliae spores. The pure conidia were suspended in Tween 80 (R) (0.1%) and calibrated to the concentrations of 1 x 10(6), 10(7), 10(8) and 10(9) 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 10(9) conidia/g dry mass of substrate + fungus. The water content of 6.36% of the single spore powder (pure conidia) separated by the Mycoharvester (R) was lower than that of the agglomerated product. The product harvested at the concentrations of 10(8) and 10(9) 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 (R) is an important step toward optimizing the fungal production system of pure conidia, and to formulate biopesticides for insect pest management.

Automated summary

This study evaluated the effectiveness of Mycoharvester (R) equipment in harvesting and separating pure Metarhizium anisopliae conidia for controlling Thaumastocoris peregrinus Carpintero & Dellape, 2006. The equipment harvested 85% of the conidia from rice, with a production rate of 4.8 x 10^9 conidia/g dry mass of substrate + fungus. The separated pure conidia had lower water content compared to the agglomerated product. The product harvested at concentrations of 10^8 and 10^9 conidia/ml caused high mortality in T. peregrinus nymphs and adults.