Composition and fumigant protectant potential of Tunisian Citrus aurantium L. essential oils against Rhyzopertha dominica F.(Coleoptera: Bostrichidae)

In recent decades, agro-industrial waste has become recognized as a significant social, nutritional, and environmental problem. Thus, management strategies are urgent. The use of agricultural and food processing waste in new by-products is likely to out-compete any other offered solution. In this respect, the valorization of citrus peels from juices and jam industries is an important issue since Tunisia is well-known for the production of such crops. The present work assessed the insecticidal potential of essential oils extracted from the bitter orange Citrus aurantium L. as a protectant against adults of the lesser grain borer Rhyzopertha dominica F. Citrus aurantium fruit samples were collected from Nabeul and Bousselem localities (north Tunisia). Essential oils were analyzed by using gas chromatography-mass spectrometry (GC-MS) techniques and assessed for their fumigant toxicity against newly emerged R. dominica adults. Results showed quantitative and qualitative differences in oil composition in due to location. Limonene was the major and characteristic common compound with values of 92.36% and 93.69% for Nabeul and Bousselem, respectively. The fumigant bioassay showed that Citrus aurantium from Nabeul was more toxic and the corresponding LC50 and LC95 values were 307.89 and 652.91 µL/L air, respectively, within 48h of exposure. Our work indicates concern in the use of Tunisian Citrus aurantium essential oils as fumigant protectant against Rhyzopertha dominica during storage.