Asian Journal of Research in Zoology

Agricultural production and household food storage in Assam face persistent challenges from insect pests, while the use of accessible plant-based materials for pest management remains insufficiently documented at the local level. The present study aimed to document insect pests associated with selected stored grains, pulses, and fruit and vegetable crops in and around The Assam Royal Global University, Guwahati, Assam, and to obtain exploratory mortality observations following exposure of the rice weevil, Sitophilus oryzae, to two self-prepared plant-based formulations. Field surveys and household-level observations were conducted to document pest occurrence, followed by preliminary identification based on observable morphological characteristics and photographic comparison using the INSECT ID application, with nomenclatural cross-reference through the Catalogue of Life. Three plant-based formulations were prepared using Lantana camara, dry chili, clove, methanol, etc.; two formulations, LR1 (Lantana-Methanol) and LR2 (Lantana-dry Chilli-Clove), were subjected to exploratory mortality observations against S. oryzae over a seven-day period. A total of 47 deaths were recorded following LR1 exposure, with 3 individuals remaining alive at the final observation, while 33 deaths were recorded following LR2 exposure, with 17 individuals remaining alive. FT-IR analysis of the two tested formulations provided preliminary information on their functional-group profiles. The study documents locally observed crop-associated pests and provides preliminary mortality observations for two self-prepared formulations. However, untreated and solvent controls, biological replication, and concentration-response testing were not included in the original bioassay; therefore, the observed mortality cannot be attributed specifically to the plant-derived constituents or used to establish formulation efficacy. Similarly, the preliminary taxonomic identifications were not independently verified using standardised taxonomic keys or expert confirmation. The findings should therefore be regarded as baseline observations that warrant validation through controlled, replicated, and taxonomically verified future studies.