The synanthropic housefly, Musca domestica, augments the transmission of several detrimental diseases like cholera and avian flu. Consequently, during the last century, many physico-chemical methods including synthetic compounds have been applied for its control. But these methods have proven to be prohibitive due to their side effects and serious issues like resistance development, environmental contamination, and detrimental effects on non-target fauna. Therefore, in view of these objectives, we investigated the effects of bay essential oil (EO) against M. domestica. The attractant/repellent assays were conducted by double choice technique. Different enzyme assays evaluating the effect of LC50 concentration of the tested essential oil on larval gut were taken into consideration. To determine the composition, the tested oil was subjected to GC-MS/MS analysis. Further, the morphological alterations caused by EO treatment to third instar larvae were observed in a Nova Nano SEM machine. Data was statistically analyzed by one-way ANOVA using Tukey’s test (p < 0.001). The LC50 and LC90 values were calculated by probit analysis. The adulticidal bioassay revealed significant effects with LC50 concentration as 43.03 mg/dm3 against the newly emerged adult flies while in larvicidal assay mortality was dose dependent showing maximum effect at LC50 0.0629 μg/cm2. The pupicidal activity was more effective at a dose of LD50 64.09 μl/0.25 L of air which either killed the pupae or caused deformity in the emerged adults. Likewise total sugar, protein, glycogen, and lipid contents of larvae were reduced after treatment with EO when compared with the normal larvae along with some gut enzymes. The EO reduced the acetylcholinesterase activity from 0.013 U/mg protein in normal larvae to 0.0093 U/mg protein after EO treatment. The GC-MS/MS analysis of the bay EO showed the abundance of myrcene, linalool, eugenol, chavicol, and anethole along with diterpenoid, geranylgeraniol. However, the insecticidal activity of tested EO might be majorly imparted by eugenol content. The FESEM analysis showed shrinkage of integument and distortion to intersegmental regions caused by the tested compound. The present study concludes the significant efficacy of bay EO against M. domestica which could be employed to breakdown its population below threshold levels to prevent the menace of vector-borne diseases.

中文翻译：

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月桂精油对家蝇、家蝇（双翅目：蝇科）的生防功效

合人类家蝇，家蝇，增加了霍乱和禽流感等多种有害疾病的传播。因此，在上个世纪，包括合成化合物在内的许多物理化学方法已应用于其控制。但这些方法已被证明是禁止的，因为它们有副作用和严重的问题，如抗性发展、环境污染和对非目标动物群的不利影响。因此，鉴于这些目标，我们研究了月桂精油 (EO) 对家蝇的影响。通过双重选择技术进行引诱剂/驱避剂测定。考虑了评估受试精油的 LC50 浓度对幼虫肠道影响的不同酶测定。为了确定成分，对测试油进行 GC-MS/MS 分析。此外，在 Nova Nano SEM 机器中观察到由 EO 处理对三龄幼虫造成的形态变化。使用 Tukey 检验通过单向方差分析对数据进行统计分析 (p < 0.001)。LC50 和 LC90 值通过概率分析计算。杀成虫生物测定显示 LC50 浓度为 43.03 mg/dm3 时对新出现的成年果蝇有显着影响，而在杀幼虫测定中，死亡率呈剂量依赖性，显示 LC50 为 0.0629 μg/cm2 时的最大作用。在 LD50 64.09 μl/0.25 L 空气的剂量下，杀蛹活性更有效，这会杀死蛹或导致成虫畸形。同样，总糖、蛋白质、糖原、与正常幼虫和一些肠道酶相比，用 EO 处理后幼虫的脂质含量和脂质含量降低。EO 将乙酰胆碱酯酶活性从正常幼虫的 0.013 U/mg 蛋白降低到 EO 处理后的 0.0093 U/mg 蛋白。海湾 EO 的 GC-MS/MS 分析显示月桂烯、芳樟醇、丁香酚、查维醇和茴香脑以及二萜、香叶基香叶醇的丰度。然而，测试的 EO 的杀虫活性可能主要受丁香酚含量的影响。FESEM 分析显示由测试化合物引起的珠被收缩和节间区域变形。本研究得出的结论是 bay EO 对 M.domestica 的显着功效，可用于将其种群分解到阈值水平以下，以防止病媒传播疾病的威胁。