Limonoids and insecticidal activity on Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae) of Trichilia catigua A. Juss. (Meliaceae)

The aim of the study was to evaluate the effects of the seeds, exocarp and aril extracts from Trichilia catigua A. Juss. (Meliaceae) against Spodoptera frugiperda and present the phytochemical study carried out with the aril extract of T. catigua. Limonoids were isolated from the aril of T. catigua through chromatographic techniques and their structures were proposed by spectroscopic analysis and comparison with literature data. The effects of the seeds, exocarp and aril extracts from T. catigua against S. frugiperda were evaluated considering as parameters the duration and mortality of the larval phase, in addition to the pupal weight. Phytochemical investigation of the aril extracts of T. catigua has led to the identification of the limonoids 6 alpha-O-acetyl-7-deacetyl-14,15-dihydro-15-oxo-nimocinol (1), cedrelone (2) and 6 alpha-O-acetyl-7-deacetylnimocinol (3). The hexane and CH2Cl2 extracts of the aril showed a high rate of larval mortality (100 and 90%, respectively). In addition, a prolongation of larval phase and a reduction in the pupal weight were observed for insects treated with hexane, CH2Cl2 and methanol extracts of seeds and with CH2Cl2 extract of exocarp of T. catigua.

Automated summary

The aim of this study was to assess the effects of extracts from Trichilia catigua A. Juss. on the fall armyworm and conduct a phytochemical study on the aril extract. Limonoids were isolated and their structures were identified. The extracts showed high larval mortality, prolonged larval phase, and reduced pupal weight in the fall armyworm.