Effets protecteurs de l’huile essentielle de cymbopogon citratus (citronnelle) sur le poisson fumé (clarias gariepinus) en stockage contre deux insectes ravageurs

Abstract

Fish plays an important role in the world because it contains most of the vitamins and trace elements needed to fill some of the most serious and widespread deficiencies, and it is one of the segments of the global food sector where trade is enormous. This very rich food faces various problems including deterioration due to its own enzymes, microbial proliferation, losses caused by mites and insecte pests during storage. Chemicals are the means of control, unfortunately these products are extremely dangerous. Cymbopogon citratus has long been used for its fungicidal and also insecticidal and insect repellent effects on various populations of stored foodstuffs, and would be an alternative to these dangerous pesticides. The study aims to evaluate the protective effects of Cymbopogon citratus essential oils, in particular Cymbopogon citratus mycorrhizae, on smoked fish in storage against two insect pests. To achieve this, the toxicity of the essential oils was carried out in vitro by contact on filter paper. The insect repellent effect was performed In vitro using the preferential zone method in petri dishes. The fumigation test was carried out in the glass jars of 270 cm volume with leak-proof lids, filter paper discs (Whatman HPL3.1) with a surface area of 9 cm were each fixed with a black wire in the center of the inner side of the lids so that they take the middle height of these jars and 1ml of the essential oil solutions were spread. The direct contact test on smoked fish was carried out in the 5-litre buckets. The results obtained reveal that essential oils have repellent activities with rates of 100% and 97.5% respectively of Dermetes maculatus and Necrobia rufipes, and insecticidal activities with mortality rates of 92.5% of D. maculatus and 97.5% of N. rufipes at a dose of 5%. Cymbopogon citratus mycorrhizal essential oil significantly influenced mortality rates compared to non-mycorrhizal Cymbopogon citratus essential oil. Cymbopogon citratus essential oils have insecticidal activities against both insects studied.