Virulence of the Bio-Control Fungus Purpureocillium lilacinum Against Myzus persicae (Hemiptera: Aphididae) and Spodoptera frugiperda (Lepidoptera: Noctuidae)

Abstract

Eco-friendly entomopathogenic fungi are widely used to control agricultural insect pests. Purpureocillium lilacinum (Thom.) Luangsa-ard et al. (Hypocreales: Ophiocordycipitaceae) is a nematophagous fungus used for the bio-control of destructive root-knot nematodes. However, its insecticidal activities against agricultural insect pests haven’t been widely studied. In this study, P. lilacinum PL-1 was isolated from soil (Hefei, China) and identified by molecular and morphological analyses. The growth rate, spore production, proteinase, and chitinase activities of the isolate were analyzed. Virulence tests against green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae) and fall armyworm (FAW), Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) were performed. The median lethal concentration (LC50) and median lethal time (LT50) against aphids (via immersion) and LT50 against FAW (via injection) were determined. FAW eggs immersed in aqueous conidia suspension were infected after 60 h. Differentially expressed genes (DEGs) in the infection of FAW larvae by P. lilacinum were analyzed by quantitative reverse transcription PCR. The significantly upregulated DEGs include FAW immune genes (antimicrobial peptides, C-type lectins, lysozymes, prophenoloxidase, and peptidoglycan recognition proteins) and fungal pathogenic genes (ligase, chitinase, and hydrophobin). Our data demonstrate that P. lilacinum can be used as an entomopathogenic fungus against agricultural insect pests.

Dual RNA Sequencing of Beauveria bassiana-Infected Spodoptera frugiperda Reveals a Fungal Protease with Entomopathogenic and Antiphytopathogenic Activities

“…25 Purpureocillium lilacinum (Hypocreales: Ophiocordycipitaceae) was found to be effective against S. frugiperdaeggs instead of larvae. 26 B. bassiana ZK-5 can kill 90% of S. frugiperda eggs and 60% of newly emerged larvae (neonates), while the mortality rate of first to sixth instar larvae decreased from 20.0 to 7.8%. 27 Using UV-induced mutagenesis, we obtained two hypervirulent isolates of B. bassiana that exceeded the efficiency of the wild-type strain Bb2860.…”

“…Purpureocillium lilacinum (Hypocreales: Ophiocordycipitaceae) was found to be effective against S. frugiperdaeggs instead of larvae B.…”

Discovery of entomopathogenic fungi across geographical regions in southern China on pine sawyer beetle Monochamus alternatus and implication for multi-pathogen vectoring potential of this beetle

“…However, P . lilacinum has been reported to be a strong parasitic entomopathogen of aphid and moth insect pests that secretes proteases and chitinases ( Liu et al., 2022 ). Similarly, P .…”

UV‐induced mutagenesis of Beauveria bassiana (Hypocreales: Clavicipitaceae) yields two hypervirulent isolates with different transcriptomic profiles

“…The chitinase activity was measured according to a previous method 22 . Briefly, WT and mutants were cultured in 30 mL SDY at 28°C.…”

“…The chitinase activity was measured according to a previous method. 22 Briefly, WT and mutants were cultured in 30 mL SDY at 28°C. Next, 0.1 mL of 1% chitin medium (1% colloidal chitin, 0.4% NH 4 NO 3 , 0.05% K 2 HPO 4 , 0.05% MgSO 4 •7H 2 O, 0.05% KCl, 0.001% FeSO 4 •7H 2 O) was mixed with 0.1 mL cell-free culture supernatant and incubated at 45°C for 1 h. Then, 0.2 mL of 3,5-dinitrosalicylic acid (DNS) was added to stop the reaction.…”