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As alternatives to chemical insecticides, entomopathogenic fungi or wild plants and their secondary metabolites are being used. These biocontrol agents are significant because of their biodegradability, specificity, eco-friendliness, and utility as agents to reduce insecticide resistance. In this study five ethyl acetate extracts of locally isolated fungal strains (Talaromyces atroroseus, Fusarium chlamydosporum, Talaromyces stipitatus, Trichoderma lixii, Beauveria bassiana) as well as alkaloid extract of Haloxylon salicornicum were extracted and investigated as biocontrol agents against cotton mealybug Phenacoccus solenopsis. The results indicated that all extracts had toxic effects against P. solenopsis except the extract of T. stipitatus. The LC50 values and toxicity index indicated that the alkaloid extract of H. salicornicum was the most toxic one (26 ppm) after 72 hours of treatment followed by the extracts of F. chlamydosporum (77 ppm), then B. bassiana (84 ppm) and T. lixii (118 ppm). On the other hand, there were significant changes in tested insect enzyme activities (amylase, lipase, glutamic oxaloacetic transaminase (GOT), glutamic pyruvic transaminase (GPT), and acetyl choline esterase (AchE) as well as total proteins and lipids in the insects treated with the alkaloid extract of H. salicornicum, and ethyl acetate extracts of F. chlamydosporum and B. bassiana after 24 hours of treatment compared to the control. GC/MS analyses of fungal extracts indicated that there were some bioactive compounds like hexadecanoic acid, octadecanoic acid, and tetradecanoic acid. In addition, the anabasine compound was found as a major constituent of the alkaloid extract of H. salicornicum and identified by 1H NMR and GC/MS analysis. In conclusion, according to this study, it was recommended that the alkaloid extract of H. salicornicum and the ethyl acetate extracts of F. chlamydosporum, B. bassiana, and T. lixii be used as alternatives to chemical insecticides for controlling the cotton mealybug P. solenopsis. [ABSTRACT FROM AUTHOR]

Cotton aphids, Aphis gosspyii and cotton jassids, Amrasca biguttula are destructive piercing sucking pests to many strategic crops, especially cotton, not only in Egypt but also all over the world. Using synthetic pesticides to control these pests led to several deleterious impacts. Natural pesticides can be used as a harmless alternative. Nine compounds were isolated from different fractions of Retama raetam using chromatographic techniques and identified by spectroscopic methods as eugenol (1), alpinumisoflavone (2), licoflavone C (3), ephedroidin (4), anagyrine (5), spartiene (6), genistein-8 β -C-glucoside (7), isoprunetin (8) and isoprunetin 7-O- β -D-glucopyranoside (9). The methanol crude extract and its fractions (hexane, chloroform, ethyl acetate and butanol), as well as the isolated compounds were examined against A. gosspyii and A. biguttula as insecticides. The results showed that chloroform fraction was the most potent fraction against A. gosspyii and A. biguttula, with LC 50 values of 65.66 and 64.43 ppm, respectively. As well, compounds 1 , 5 and 6 were found to be more active, with LC 50 values of 69.84, 25.49 and 27.22 ppm for A. gosspyii and 65.17, 24.07 and 24.78 ppm for A. biguttula , respectively. The most potent compounds (1 , 5 and 6) exhibited AChE inhibition toward A. gosspyii compared with the control. So, it can be concluded that the isolated compounds eugenol 1 , anagyrine 5 and spartiene 6 are the active principles due to their capability to inhibit AchE activity. [Display omitted] • Seven polyphenol and two alkaloid compounds were isolated and identified from Retama raetam plant. • Insecticidal activities of different fractions and isolated compounds were studied on Aphis gosspyii and Amrasca biguttula. • Eugenol, anagyrine and spartiene are the active principles due to their capability to inhibit AchE activity. [ABSTRACT FROM AUTHOR]