Compatibility of different Metarhizium spp. propagules with synthetic acaricides for controlling Rhipicephalus microplus

Abstract

The inappropriate use of synthetic acaricides has selected resistant Rhipicephalus microplus populations. The present study evaluated the compatibility of different Metarhizium spp. propagules (conidia, blastospores, and microsclerotia) by incubating them with synthetic acaricides (amitraz, deltamethrin, and a combination of cypermethrin, chlorpyrifos, and citronellal) for 1 h, 5 h, 10 h, and 24 h. Conidia and microsclerotia of the tested isolates were usually more tolerant to synthetic acaricides than blastospores. Our study also analyzed the in vitro effect of deltamethrin associated with fungal propagules for controlling a population of R. microplus females that were not susceptible to this synthetic acaricide. The use of entomopathogenic fungi in association with deltamethrin in this tick population caused a greater tick control than did the use of the fungus or the synthetic acaricide separately.

Utilization of Metarhizium as an insect biocontrol agent and a plant bioinoculant with special reference to Brazil

“…Furthermore, Metarhizium spp. infections in ticks have been reported, both in the field and in semi-field conditions, demonstrating biocontrol results for Rhipicephalus microplus (Camargo et al, 2016;Marciano et al, 2021;Carneiro et al, 2022) and Rhipicephalus sanguineus (Reis et al, 2008) in Brazil. (Jaronski, 2007), and many have been demonstrated to be rhizosphere competent (Hu and St. Leger, 2002;Hu and Bidochka, 2021a), and these features can be exploited in biocontrol efforts (Bamisile et al, 2023).…”