Cinnamomum verum, a source of phytocompound leads against Odoiporus longicollis (Coleoptera: Curculionidae).

Bananas are the fourth most important food crop in the world. Odoiporus longicollis (Oliver), commonly called the banana pseudostem weevil, is one of the serious insect pests that affect the banana production. Though cultural practices and synthetic insecticides are used against this insect pest, indiscriminate use of the synthetic insecticides is expensive, causes health problems or develops pest resistance. The present study was conducted to investigate the insecticidal efficacy of Cinnamomum verum against the fourth instar larvae of O. longicollis, its impeding effects on the pest, and identify the potential bioactive compounds. The acetone extract of the plant showed larvicidal activity in a dose-dependent manner with an LD50 value of 4.12 g/100 mL. The extract induced hyperproteinemia, increased amino acid content, correlated variations in the activity of aspartate transaminase and alanine transaminase, an increase in trehalose content, and a reduction in the haemocyte count of the haemolymph. Fourier transform infrared spectroscopy and high resolution mass spectroscopy analyses of the extract could identify three bioactive compounds: trans-13-octadecenoic acid, 9-octadecenamide and spiro(tricyclo(4.4.0.0.(5.9)]decane-10,2'- oxirane],1- methyl -4- isoprol (relative abundance 7%, 29% and 13%, respectively), resulting in synergistic action. The results suggest C. verum could be used as a source of natural insecticidal agents for the management of O. longicollis, as an alternative to synthetic insecticides. [ABSTRACT FROM AUTHOR]