Isolation, identification and virulence of indigenous entomopathogenic fungal strains against the peach-potato aphid, Myzus persicae Sulzer (Hemiptera: Aphididae), and the fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae)

Abstract

Background As different biogeographic strains and isolates of entomopathogenic fungi vary in their genetic, enzymatic and pathogenic characteristics, this study assessed the virulence of 2 indigenous strains of Beauveria bassiana (Balsam) Vuillemin and Metarhizium anisopliae (Metschn.) Sorokin (Ascomycota, Hypocreales: Clavicipitaceae), isolated from naturally infected insect cadavers, against the 3rd instar nymphs of Myzus persicae (Sulzer) (Hemiptera: Aphididae) and 3rd instar larvae of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) using leaf-dip and larval-dip methods, respectively. Results Both fungal isolates exhibited considerable pathogenicity against M. persicae and S. frugiperda. Mortality in all bioassays was conidial concentration and exposure time dependent and increased significantly along with both factors (R2 = 0.86–0.99 for B. bassiana and 0.82–0.94 for M. anisopliae). Moreover, M. anisopliae isolate appeared more virulent to S. frugiperda larvae than B. bassiana isolate, while the later fungal isolate was more lethal to M. persicae nymphs than the former one. At the highest conidial concentration (1.0 × 109 conidia/ml), M. anisopliae caused maximum mean mortality of S. frugiperda (88%) and M. persicae (65%) and B. bassiana exhibited maximum mean mortality of S. frugiperda (76%) and M. persicae (94%). Moreover, probit regression analyses showed LT50 values for M. persicae of 4.57 and 6.86 days at 1.0 × 109 conidia/ml for the isolates of B. bassiana and M. anisopliae, respectively, while LC50 values were 7.75 × 106 and 8.70 × 107 conidia/ml after 10th day of application, for the isolates of B. bassiana and M. anisopliae, respectively, against M. persicae. Similarly, LT50 values for S. frugiperda were 7.75 and 7.03 days for 1.0 × 109 conidia/ml concentration and LC50 values were 2.84 × 107 and 8.84 × 105 conidia/ml at 10th day data for the isolates of B. bassiana and M. anisopliae, respectively. Conclusion Overall study results demonstrated the effectiveness of B. bassiana and M. anisopliae against M. persicae and S. frugiperda, respectively. However, field evaluations of these indigenously isolated promising fungal strains against these insect pests.

Pathogenic potential of Metarhizium anisopliae and Lecanicillium longisporum on tea mosquito bug, Helopeltis theivora Waterhouse (Hemiptera: Miridae)

“…Metarhizium anisopliae (Deuteromycotina: Hyphomycetes) (Sahayaraj & Borgio Francis, 2010) and Lecanicillium longisporum (Ascomycota: Hypocreomycetidae) (Rachel et al, 2009) are commercially used as a biological control agent against various insect pests. Many previous studies have found that M. anisopliae was a promising biocontrol agent on various hemipteran pests such as Bactericera cockerelli (Hemiptera: Triozidae), Lygus lineolaris (Hemiptera: Miridae), Blissus antillus (Hemiptera: Lygaeidae) and Myzus persicae (Hemiptera: Aphididae) (Lacey et al, 2011;Houping et al, 2002;Samuels et al, 2002;Ullah et al, 2022). Similarly, L. longisporum also reported effectiveness against the following hemipterans viz., Planococcus citri (Hemiptera: Pseudococcidae) and Cinara pini (Hemiptera: Lachnidae) (Ghaffari et al, 2017;Nazemi et al, 2014).…”

Identification of entomopathogenic fungus Metarhizium rileyi infested in fall armyworm in the cornfield of Korea, and evaluation of its virulence

“…The results showed that this strain (KNU‐Ye‐1) was identical to the M. rileyi KNU‐Gunwi 2 B strain, previously identified in soil samples from Korea (Moe et al, 2021). Recent studies have reported the identification and virulence of M. rileyi against invaded FAW in various Asian countries, including China (Zhou et al, 2020), India (Shylesha et al, 2018), Pakistan (Ullah et al, 2022), and the Philippines (Montecalvo et al, 2022). To our knowledge, this is the first report of a native strain of M. rileyi infestation of S. frugiperda in a corn field in Korea.…”

Biological control of Spodoptera frugiperda J.E. Smith and Schistocerca piceifrons piceifrons Walker using entomopathogenic fungi

“…In this regard, local parasitoids from these families have already been reported in Mexico and in several African countries; consequently, these parasitoids can help to keep this pest under control in the Old World (Koffi et al, 2020). Regarding entomopathogenic fungi, Metarhizium anisopliae (Mechnikov) Sorokin can cause a 43-100% mortality in third-instar larvae of S. frugiperda (Ullah et al, 2022b;Munywoki et al, 2022) and a 70-100% mortality in nymphae and adults of S. p. piceifrons. Additionally, it can cause mortality in others species of the Acrididae family, including Melanoplus sanguinipes Fabricius (Barrientos-Lozano et al, 2021;Dakhel et al, 2019).…”