Utilization of Penicillium and Mycorrhizal Fungal Species for Controlling Anopheles Mosquitoes

Abstract

Mosquito-borne diseases remain a significant public health challenge in Nigeria, with insecticide resistance increasingly compromising conventional chemical control strategies. This study evaluated the potential of Penicillium and mycorrhizal fungal species as biological control agents against Anopheles mosquitoes, specifically assessing larvicidal and adulticidal efficacy, determining lethal concentrations and times, and characterizing bioactive secondary metabolites. Mosquito larvae and adults were exposed to three concentrations (0.25 × 10⁸, 0.5 × 10⁸, 1.0 × 10⁸ CFU/ml) of fungal spore suspensions, with mortality recorded at 24, 48, and 72 hours. Bioactive compounds were identified using Gas Chromatography-Mass Spectrometry (GC-MS). Data were analyzed using one-way ANOVA and probit analysis. Penicillium species achieved 72% larval mortality at 1.0 × 10⁸ CFU/ml after 72 hours, while mycorrhizal fungi achieved 63% under identical conditions. Adulticidal activity was lower, with Penicillium causing 57% and mycorrhizal fungi 42% mortality. LC₅₀ and LC₉₀ highlighted the effectiveness of both fungi at low doses, for larvae; Penicillium LC₅₀ (1.24) is more potent than mycorrhiza (1.58). For adults both require a higher concentrations than for larvae but Penicillium (2.86) again outperforms Mycorrhiza (3.95). GC-MS analysis identified dibutyl phthalate as the predominant compound in both fungi (71.77% in Penicillium, 83.18% in mycorrhiza), along with hexadecanoic acid ethyl ester, 2, 4-di-tert-butylphenol, and various alkanes and fatty acid esters with documented mosquitocidal properties. All effects were dose-dependent and time-dependent (p < 0.05). Penicillium and mycorrhizal fungi demonstrate significant potential as biological control agents for mosquitoes