Efficacy of soil isolates of entomopathogenic fungi against the bulb mite, Rhizoglyphus robini (Acari: Acaridae)

0543615 - BC 2022 RIV GB eng J - Journal Article
Konopická, Jana - Bohatá, A. - Nermuť, Jiří - Jozová, E. - Mráček, Zdeněk - Palevsky, E. - Zemek, Rostislav
Efficacy of soil isolates of entomopathogenic fungi against the bulb mite, Rhizoglyphus robini (Acari: Acaridae).
Systematic and Applied Acarology. Roč. 26, č. 6 (2021), s. 1149-1167. ISSN 1362-1971
R&D Projects: GA MŠMT(CZ) 8G15006; GA MŠMT(CZ) LM2018129; GA MŠMT(CZ) EF16_013/0001775
Institutional support: RVO:60077344
Keywords : Alliaceae * soil mites * Metarhizium
OECD category: Agronomy, plant breeding and plant protection
Impact factor: 1.314, year: 2021
Method of publishing: Limited access
https://www.biotaxa.org/saa/article/view/62953

The bulb mite, Rhizoglyphus robini, is a serious pest of garlic, onion and other crops. The mite is usually found in association with dangerous fungal pathogens such as Fusarium spp. Control of this pest has relied upon the use of synthetic acaricides but chemical control of the bulb mite is difficult because it is able to develop resistance quickly. Thus, alternative control methods, e.g. biological control, need to be developed and implemented. The aim of this study was to assess efficacy of selected strains of entomopathogenic fungi (EPF) against adult females of R. robini under laboratory conditions. New EPF strains were isolated from soil samples collected in onion and garlic fields in the Czech Republic and Israel using soil elution and cultivation on selective media. Fungal species were determined using macroscopic, microscopic and molecular markers. The
efficacy against R. robini females was tested in 17 isolated and 3 reference strains of EPF. Results revealed high variability among species and strains. The highest efficacy against R. robini mites was found in strains of Metarhizium anisopliae isolated from soil samples collected in the Czech Republic which caused mortality up to 99.3%, and a Metarhizium indigoticum strain from Israel causing 98.3% mortality after four days of bioassay. Isaria fumosorosea strains did not caused mortality higher than 40%. The lowest virulence was found in Beauveria spp. strains causing mortality of mites between 5 and 25%. Median lethal time (LT50) and median lethal concentration (LC50) in the three most virulent strains ranged between 2 and 4 days and between 1.01×104 and 2.36×105 spores/ml, respectively. The concentration-response models indicated that the M. indigoticum strain is more lethal than M. anisopliae strains. The present study showed that some strains of entomopathogenic fungi, especially from the genus Metarhizium, could be perspective biocontrol agents against R. robini.
Permanent Link: http://hdl.handle.net/11104/0326406