Repellent effects of some plant oils on Dermestes maculatus larvae in Smoke-dried West African lungfish (Protopterus annectens)

Abstract

Dermestes maculatus accounts for about 71.5% of dried fish infestation in most of the producing areas with a substantial loss in both dry weight and nutritional value. The study aimed to evaluate the repellent effect of oils extracted from Garlic (Allium sativum), Coconut (Cocos nucifera), Ginger (Zingiber officinale), Jatropha (Jatropha curcas), and Neema (Azadirachta indica) on Dermestes maculatus larvae in smoke-dried Protopterus annectens. The extracted oils from each plant were applied to the fish at varying concentrations of 0.001, 0.004, 0.016, 0.064, and 0.256 ml/g fish in triplicates. Late instar larvae of D. maculatus were introduced into Kilner jars containing fish treated with these oils and repellency was monitored for 24 hrs. Repellency was highest (87%) in A. sativum oil and lowest (59%) in A. indica oil at the highest concentration (0.256 ml/g of fish) within 24 hrs. of exposure. Furthermore, an increasing trend in repellency was observed with increasing concentrations of oils from all the plants used. The order of repellency performance was A. sativum > C. nucifera > Z. officinale > J. curcas > A. indica, starting with the highest to the lowest. Therefore, this study demonstrates the repellent properties of the oils in offering effective protection against infestation and damage by D. maculatus, suggesting that the oils can be utilized in post-harvest preservation of smoke-dried fish.

IMPACT STATEMENT

Smoked-dried fish, a vital source of animal protein and essential nutrients, significantly contributes to food security, employment, income, and foreign exchange, supporting sustainable development. However, a major challenge is the presence of Dermestes maculatus, a pervasive pest causing substantial losses in stored dry fish. This study focuses on the repellent effect of essential oils from selected plants known for their active ingredients, to combat D. maculatus infestation in smoked-dried Proptoterus annectens. The use of plant extracts as compared to chemicals presents a more sustainable and safe approach to preserving the nutritional value of fish products. Our results suggest the use of essential oils as a recommended strategy for preventing and controlling insect infestation in smoked-dried fish.

Keywords:

• Allium sativum
• fish
• repellency
• plant oils
• fatty acids
• Cocos nucifera

Reviewing Editor:

• M. Luisa Escudero-Gilete, Universidad de Sevilla, Spain

SUBJECTs:

• Marine & Aquatic Science
• Entomology
• Food Chemistry
• Food Engineering

Acknowledgment

The authors acknowledge the support of Mr. Dipo Aribido from the National Research Institute of Chemical Technology (NARICT), Zaria, Kaduna State, Nigeria for the support rendered during the study.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

We confirm that all the data generated during this study have been included within this document.

Additional information

Notes on contributors

Folasade Damilola Amulejoye

Dr. Folasade Amulejoye, currently serving as a lecturer at the Olusegun Agagu University of Science and Technology in Okitipupa, Ondo State, Nigeria, is dedicated to advancing knowledge in the field of aquatic sciences. Her research focuses on fish nutrition, breeding, and fisheries management.

Sahya Maulu

Sahya Maulu is a PhD Researcher in Fish nutrition and health at the University of Plymouth in the United Kingdom. His main areas of expertise include novel feed ingredients in aquaculture, fish nutrition, and fish health. However, his research interests cut across the fields of Aquaculture, Fisheries, Agriculture, and climate change.