Abstract
Introduction: Houseflies (Musca domestica) are one of the most significant sources of microbial contamination in meat processing facilities, as they act as direct mechanical vectors for numerous pathogens that can adversely affect food safety and human health. Given the risks posed by conventional chemical pesticides, this study highlights the need to seek safe and environmentally friendly alternatives, such as plant extracts (thyme extracts), which can help reduce the prevalence of this insect and mitigate its harmful effects.Objective: The study aims to evaluate the biological efficacy of alcoholic and aqueous extracts of thyme in controlling the various larval stages of the housefly, with a focus on comparing their respective effectiveness in inducing mortality rates and their impact on prolonging the larval growth period, as well as to study the effect of these treatments on pupal development and the resulting pupal weights. Methods: Alcoholic and aqueous thyme extracts were used at various concentrations (15, 20, 25, and 30 mg/mL), and the three larval stages (first, second, and third) of the housefly were exposed to these extract concentrations under strictly controlled laboratory conditions. Mortality rates were recorded for each stage, larval development duration was monitored, and the survival rate and weights of the pupae were assessed, in comparison with a control group that received no treatment. Results: The results showed that the alcoholic extract was more effective than the aqueous extract, with mortality rates of 100%, 90.3%, and 74.3% in the first, second, and third larval stages, respectively, while the mortality rates for the aqueous extract were 82.2%, 60.2%, and 50% for the same stages, compared to a very low rate of 3% in the control group. An increase in larval growth duration was also observed, particularly in the first instar, which lasted 4-4.5 days compared to 2 days in the control group; in addition, the highest mortality rate (100%) was recorded among pupa that emerged from larvae treated during the first and second instar. The results also showed a significant decrease in pupae weights, with the alcoholic extract recording the lowest weight of 11 mg, while weights ranged from 17–18 mg in the aqueous extract compared to 26 mg in the control group. Conclusions: The outcomes of the study indicate that thyme extract, particularly the alcoholic extract, is highly effective as a natural insecticide against houseflies, as it caused increased mortality rates in the larval stages, slowed growth, and negatively affected the development and weight of pupae, making it a promising and environmentally friendly option that can be adopted within integrated pest management programs to limit the spread of this insect.