Prevalence of Nasopharyngeal Myiasis among Dromedary Camels and Influence of Cuts Dates on Chemical Composition, Antioxidant and Larvicidal Efficacy of Mentha longifolia L. Essential Oil against Cephalopina titillator

This study aimed to determine prevalence of nasopharyngeal myiasis among camels and evaluate the variation of Mentha longifolia oil yield, components, antioxidant activity, and larvicidal effect against Cephalopina titillator during three cuts (28 th of April, 4 th of June, and 22 nd of July).Clinical and post-mortem examinations of 300 dromedary camels slaughtered in Giza province, Egypt showed a high prevalence of nasopharyngeal myiasis (58%).Risk factors linked to high infestation were being more than 3 years old (70.8%) and cooler seasons (74%); where it reached 81.3% in Winter.The highest oil yield was obtained on the 22 nd of July.The relative percentages of the main constituents (pulegone, followed by eucalyptol, then I-menthone) showed variation in all three cuts.The highest percentage of pulegone (63.79%) was on the 28 th of April, followed by 62.41% on the 4 th of June, and decreased to 55.25% on the 22 nd of July.In contrast, the 3 rd cut produced the highest Eucalyptol (18.26%) and I-menthone (9.83%).M. longifolia oil at 200mg/mL caused 100% mortality of 2 nd and 3 rd larvae within 2 and 8h, respectively.Essential oil of the 2 nd cut showed superior efficacy compared to ivermectin-treated larvae, with lower LC50 and LC90 values.Light and scanning electron microscopy revealed significant damage to the oil treated larvae, including swelling, degeneration, and atrophy of the cuticle, the mouthparts and antennal lobes.These findings highlighted the danger of nasopharyngeal myiasis, effect of cut dates on M. longifolia oil yield and constituents, and its potent anti-C.titillator.