Virulence effect of Metarhizium anisopliae (Met.) and Beauveria bassiana (Bals.) fungi against the peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae)

Abstract

Background The peach fruit fly, Bactrocera zonata (Saunders) (Diptera: Tephritidae), is a key pest of fruits in Egypt. Insect-pathogenic fungi are one of the biocontrol agents that increasingly substitute the traditional pesticides to overcome pesticide risks. Therefore, the present study aims to assess the fungal virulence of Beauveria bassiana (Balsamo) and Metarhizium anisopliae (Metchnikoff) against B. zonata pupae. Also, extended pathogenicity effect of these fungi on adult flies was studied. Results The results showed that M. anisopliae fungus had more pathogenicity to B. zonata pupae on the 2nd, 3rd, and 5th days post-treatment than B. bassiana. Pathogenicity fungal effects of treated larvae extended to the surviving adults. Fungal concentration and post-exposure interval reversely impacted the pupae by 63.88 and 63.59% mortality in the case of M. anisopliae and B. bassiana, respectively. The lethal concentration of treated fly by M. anisopliae (LC50 = 9.5 × 106 conidia/ml and LC90 = 9.9 × 107 conidia/ml) was lower than that of B. bassiana (LC50 = 5.1 × 107 conidia/ml and LC90 = 1.9 × 109 conidia/ml). Median lethal time (LT50) value was fungal species-dependent, and concentration. Metarhizium anisopliae was more virulent than B. bassiana; the lowest LT50 value was 9.48 days by M. anisopliae and 13.33 days by B. bassiana, depending on the fungal tested concentration of 2.3 × 106 conidia/ml. Conclusions The tested entomopathogenic fungi could be considered promising biocontrol agents against B. zonata and could be used for fly suppression through soil application in IPM programs.

The infection efficacy ofMetarhiziumstrains (Hypocreales: Clavicipitaceae) against the Queensland fruit flyBactrocera tryoni(Diptera: Tephritidae)

“…The Metarhizium pathogenicity (predominately Metarhizium anisopliae ) against various fruit fly species have been reported in other studies, including Bactrocera zonata ( Ibrahim et al 2014 , Gul et al 2015 , Hussein et al 2018 , Ahmad et al 2022 , El-Gendy et al 2022 ), Bactrocera cucurbitae ( Sookar et al 2014 , Hamzah et al 2021 , Iqbal et al 2021 ), Bactrocera dorsalis ( Faye et al 2021 , Melesse and Ferdu 2021 , Wang et al 2021 , Wangkeeree and Suwanchaisri 2022 ), and Ceratitis capitata ( Castillo et al 2000 , Ekesi et al 2002 , Quesada-Moraga et al 2006 , Beris et al 2013 , Soliman et al 2020 ), with limited research focus on Qfly fungal entomopathogens ( Carswell et al 1998 ). The strains used in the current study originated from local banana farm soils, and local adaption by these strains may facilitate prolonged control due to climate suitability ( McGuire and Northfield 2021 ).…”

Review of entomopathogenic fungi and nematodes as biological control agents of tephritid fruit flies: current status and a future vision

“…Screening of highly virulent strains or isolates is the primary step in biopesticide development. Mostly under laboratory conditions, fungal species or strains of M. anisopliae and B. bassiana are tested against fruit flies and often cause substantial mortality and sometimes more mortality than other EPFs (Dimbi et al, 2003a; Mahmoud, 2009; Imoulan & Elmeziane, 2014; Soliman et al, 2020; Usman et al, 2020a; Wang et al, 2021; El‐Gendy et al, 2022). Synergistic effects were obtained on larvae, pupae, and adults of Bactrocera zonata (Saunders) when M. anisopliae was combined with either B. bassiana or Lecanicillium muscarium R. Zare & W. Gams (Cordycipitaceae) (Mahmoud, 2009), compared to individual treatments.…”