Efficacy of Carum copticum extract as a green pesticide against groundnut seed beetle, Caryedon serratus

Abstract Background Caryedon serratus (Olivier, 1790) (Coleoptera: Chrysomelidae) is a major groundnut pest that infests groundnut kernels. This study aimed to extract phytochemicals from Carum copticum using a Soxhlet extractor with methanol as an organic solvent and to evaluate their efficacy against C. serratus. Results Methanolic extract and its fractions showed significant adulticidal effects after 4 days of treatment, with 87.11 ± 2.21% and 70.10 ± 2.52%, respectively. A sex ratio imbalance, extension or reduction of developmental phases, decreased fecundity, and reduced fertility. In comparison to the control, the hexane fraction produced fecundity averages of 55.33 ± 2.01 eggs, and the ethyl acetate fraction produced an average of 41 ± 0.25 eggs, corresponding to reductions in spawning rates of 52.93% and 63.25%, respectively. Gas chromatography–mass spectrometry (GC–MS) were used to identify the major bioactive chemicals in C. copticum , and there was thymol (C 10 H 14 O), 1-methylbenzene (toluene, C 10 H 14 ), 7-oxabicycloheptane (C 10 H 18 O), 1-pentene4-methyl (C 6 H 12 ), and octane (C 8 H 18 ). C. serratus was exposed to three distinct concentrations of the plant's crude and fractions of extract of organic solvents (hexane, ethyl acetate, and methanol). Conclusions All concentrations caused substantial mortality in C. serratus eggs and adults. This study shows that the efficacy of C. copticum is due to the active chemicals present in the extract that can be employed as a biocontrol agent against the major pest C. serratus .