Efficacy of Moringa oleifera Seed and Leaf Powders as Natural Insect Repellents in the Preservation of Sun-Dried Mormyrus Fish in Mubi-Nigeria

Abstract

Insect infestation poses a major threat to the quality and shelf life of sun-dried fish, causing physical damage and nutritional losses. The search for eco-friendly alternatives to chemical preservatives has led to the exploration of plant-based bio-pesticides. This study investigated the potential of Moringa oleifera seed and leaf powders as natural insect repellents for preservation in sun-dried Mormyrus fish in Mubi, Adamawa State, Nigeria. Freshly dried Mormyrus fish samples were collected from fishers at Kiri Reservoir and transported to Mubi for experimentation. Moringa leaves and seeds were shade-dried, ground into fine powders, and applied at varying concentrations. Five treatments were established: T1 (control, no treatment), T2 (25 g moringa leaf powder MLP), T3 (50 g MLP), T4 (25 g moringa seed powder MSP), and T5 (50 g MSP), each replicated three times. One hundred grams of sun-dried fish were stored per carton (15 cartons in total) for 90 days under ambient conditions. Four insect species were identified during the storage period: Necrobia rufipes adults, N. rufipes larvae, Dermestes maculatus adults, and Diptera larvae. The control (T1) recorded the highest infestations with 5.67 adult N. rufipes and 23.66 Diptera larvae, whereas T5 (50 g seed powder) recorded the lowest numbers (2.67 adult N. rufipes and 7.00 Diptera larvae). The highest mortality of N. rufipes larvae (310.33) occurred in T5, while adult D. maculatus mortality (2.33) peaked in T3 (50 g leaf powder). The application of M. oleifera seed and leaf powders effectively reduced insect infestation and increased pest mortality in sun-dried Mormyrus fish. These findings suggest that moringa-based powders are promising eco-friendly alternatives for fish preservation. Future research should explore the synergistic effects of moringa with other botanical extracts and evaluate its long-term efficacy as a biological control agent.