Insecticidal Activity of Secondary Metabolites of Locally Isolated Fungal Strains against some Cotton Insect Pests

Abstract

Microbial pest control is one of the best alternatives to chemical insecticides. Beauveria bassiana and Trichoderma harzianum are important entomopathogens of many insect pests. Cotton leafworm (Spodoptera littoralis) and aphids (Aphis gossypii) are the most destructive pests in crop production such as cotton, cabbage, tomato, potato, and lettuce. The present study sought to isolate both fungal strains (B. bassiana and T. harzianum) and extract their secondary metabolites by ethyl acetate then evaluate the efficacy of crude extract against both insect pests (S. littoralis and A. gossypii). Also, Gas chromatographymass spectrometry (GC-MS) analysis was conducted to both extracts of isolated fungi. The results indicated that both extracts of tested fungi have insecticidal activity against both tested insects. B. bassiana extract was more toxic against both insects than T. harzianum. The extract of T. harzianum was more toxic against A. gossypii more than S. littoralis. The LC 50 values of B. bassiana and T. harzianum against S. littoralis were 575 and 3238 ppm respectively but, they were 226 and 389 ppm against A. gossypii respectively. GC-MS analysis indicated the presence of some identified compounds as insecticides in both extracts of fungi such as: n-Hexadecanoic acid; Hexadecanoic acid, methyl ester; 9,12-Octadecadienoic acid, methyl ester, (E,E)-; Tetradecanoic acid, 12-methyl-, methyl ester; 7,10-Octadecadienoic acid, methyl ester and trans-13-Octadecenoic acid. This study recommended that the ethyl acetate extract of both tested fungi can be used as an alternative of chemical pesticides to control A. gossypii but in the case of S. littoralis can be used the extract of B. bassiana only.

Phytochemical, Cytotoxic, and Antimicrobial Evaluation of Tribulus terrestris L., Typha domingensis Pers., and Ricinus communis L.: Scientific Evidences for Folkloric Uses

“…These derivatives are reported to be important in personal care products such as hair and skincare, antiperspirants, and deodorants. Their antibacterial, antifungal [ 28 ], insecticidal, antimicrobial [ 36 , 37 ], and preservative properties [ 27 ] have been reported. Six different types of fatty acid esters were identified in both methanol extracts with reported antioxidant, thyroid inhibitor [ 33 ], anticancer [ 34 ], anti-inflammatory [ 32 ], hemolytic, antiandrogenic, lubricant, pesticide, nematicide, hypocholesterolemic [ 30 ], and dienophilic [ 31 ] activities.…”

Agro-waste derived compounds (flax and black seed peels): Toxicological effect against the West Nile virus vector, Culex pipiens L. with special reference to GC–MS analysis

“…A literature survey regarding the biological activities of the phytochemical constituents of our studied extracts in GC–MS profiling Table 2 showed that there are many studies reporting many biological activities of the same obtained constituent in our study from a variety of botanical extracts. Many biological activities including the insecticidal activity are recorded for the following constituents: 9-2-Methyl-Z, Z-3, 13 octadecadienol (terpenoid) which act as a Pesticide, herbicide, insecticide and as a pheromone [ Adeyemi et al, 2017 ], the second constituent: 9,17-Octadecadienal, (Z)- an insecticidal Aldehydecompound and act also as an Antieczemic, Nematicide, Antihistaminic and Antimicrobial [ Oni et al, 2020 ], the third constituent, Nonanoic acid, 9-oxo-, methyl ester a Potent antifungal, Antioxidant, Potent Antimicrobial [ Sen et al, 2017 ] beside its larvicidal activity [ Sen et al, 2017 ], fourthly 9,12-Octadecadienoic acid (Z,Z)- known as linoleic acid a Polyunsaturated Fatty acid which has many activities like Insecticidal activity [ Christiana et al, 2019 ], Anti-inflammatory, Hypocholesterolemic Cancer preventive, Hepatoprotective, Nematicide Insectifuge, Antihistaminic Antieczemic, Antiacne, 5-Alpha reductase inhibitor Antiandrogenic, Antiarthritic and Anticoronary, [ Adeyemi et al, 2017 ] and finally Octasiloxane, 1,1,3,3,5,5,7,7,9,9,11,11,13,13,15,15-hexadecamethyl- which has an antimicrobial activity)[ Ahmed et al, 2020 ] beside its insecticidal activity [ Abdullah, 2019 ].…”

Correlation between Irradiation Treatment and Metabolite Changes in Bactrocera dorsalis (Diptera: Tephritidae) Larvae Using Solid-Phase Microextraction (SPME) Coupled with Gas Chromatography-Mass Spectrometry (GC-MS)

“…Considering the pathways and mechanisms of fatty acid synthesis in insects, this result may be caused by the enhancement of the activity of key enzymes such as Acetyl CoA carboxylase or fatty acid synthase, leading to a certain degree of lipid accumulation [ 43 , 44 , 45 , 46 ]. Moreover, n-Hexadecanoic acid and Tetradecanoic acid were found to be responsible for the insect growth inhibitory and insecticide activity [ 47 , 48 , 49 , 50 ]. Therefore, irradiation treatment can lead to fatty profile changes and was found to be lethal to treated insects, but the mechanism was more complicated than we expected.…”