The efficacy of three formulations (i.e., natural lavender crude, essential oil, and gel) extracted from Lavender angustifolia was tested against vectors of the epidemic dengue virus, Aedesaegypti, to evaluate their larvicidal activity effect. The ethanolic extract of the lavender crude was prepared using a rotary evaporator, while the other extracts, such as essential oil and gel, were obtained from iHerb, a supplier of medicinal herbs in the US. The mortality rate of larvae was evaluated 24 h after exposure. Larvicidal activity of the lavender crude was 91% mortality at 150 ppm, 94% for essential oil at a concentration of 3000 ppm, and 97% for lavender gel at a 1000 ppm. Natural lavender crude was one of the most promising extracts tested against Ae.aegypti larvae, with lethal concentrations at LC₅₀ and LC₉₀ of 76.4 and 174.5 ppm post-treatment. The essential oil had the least effect on mosquito larvae, with LC₅₀ and LC₉₀ reaching 1814.8 and 3381.9 ppm, respectively. The lavender gel was moderately effective against Ae. aegypti larvae, with LC₅₀ and LC₉₀ values reaching 416.3 and 987.7 ppm after exposure. The occurrence of morphological abnormalities in the larvae treated with the three compounds, in turn, resulted in an incomplete life cycle. Therefore, our results indicated that natural lavender crude displayed the highest larvicidal activity against larvae, followed by gel and essential oil. Thus, this study concluded that lavender crude is an effective, eco-friendly compound that can be used as an alternative to chemical products to control vector-borne epidemic diseases.

Wolbachia are endosymbiotic bacteria found within many arthropods, including insects. A variety of benefits are provided by these bacteria to human and insect hosts, including protection from viruses and parasites and the ability to kill males. In this study, Wolbachia was identified in Aedes aegypti present in Jeddah, Saudi Arabia. A population of mosquitoes was collected from eight different areas, processed, and tested for Wolbachia using 16 S rRNA specific to Wolbachia bacteria and Wolbachia surface protein (wsp) under optimized PCR conditions. In five ecologically diverse sites to determine Wolbachia prevalence, we identified eleven diverse novel resident Wolbachia strains within Ae. Aegypti for the first time in Jeddah, Saudi Arabia. Future studies to evaluate the possible use of Wolbachia as a control agent in Aedes sp. in Saudi Arabia are necessary. Wolbachia prevalence rates and strain characterization through Sanger sequencing with multilocus sequence typing (MLST) and phylogenetic analysis revealed significant diversity. In developing biocontrol strategies, it is beneficial to consider the implications of resident Wolbachia strains.

Background: Forensic entomology utilizes insects for legal and criminal investigations, particularly in determining the time of death when traditional medical parameters become ineffective after 72 h. Insects play a crucial role in Post-Mortem Interval (PMI) estimation and provide insight into crime scene events. Methods: This study focused on the collection and molecular identification of forensic insects in Jeddah, Saudi Arabia. Rabbit carcasses were used as human analogs and were placed in specialized cages across five locations. Insects were collected twice daily for two weeks and identified based on their morphological and molecular characteristics. DNA extraction, polymerase chain reaction (PCR)and sequencing were used for genetic analysis. Result: Phylogenetic analysis revealed significant genetic similarities among the collected species, indicating low genetic diversity and a stable population structure. The key species identified were Sarcophaga dux, Wohlfahrtia nuba, Sarcophaga harpax, Chrysomya albiceps, Chrysomya megacephala, Chrysomya marginalis, Atherigona orientalis, Musca domestica and Hydrotaea capensis. These findings support the use of genetic analysis for accurate species identification in forensics. Additionally, this study highlights the potential impact of climate change on insect populations, suggesting future research directions in forensic entomology. This study contributes to the understanding of forensic insect ecology in the Kingdom of Saudi Arabia and enhances forensic investigation methods.

Mango fruits are one of the strategic fruit crops in different countries that are attacked by several serious pests such as Cryptoblabes gnidiella and Scirtothrips mangiferae. Natural extracts, especially essential oils, provide several promising insecticide agents to control different insects as an alternative to synthetic insecticides. Using Clevenger-type hydrodistillation, the essential oils of five thyme plants—Thymus vulgaris, Origanum vulgare, Thymus argenteus, Thymus citriodorus, and Origanum syriacum—from Saudi Arabia and Egypt were extracted, and GC/MS analysis was performed. In addition, some chemical parameters of the five species were determined, such as chlorophyll a, chlorophyll b, β-carotene, total antioxidant capacity, total phenols, and total flavonoids. Two compounds, thymol and carvacrol, were identified in T. vulgaris and O. vulgare at ratios of 69.45 and 64.82%, respectively. These major compounds were isolated and identified using ¹H NMR analysis. The insecticidal potentials of the five essential oils and their pure isolated compounds were evaluated on C. gnidiella and S. mangiferae on mango inflorescences. The results showed that T. vulgaris and O. vulgare oils were the most potent against C. gnidiella (LC₅₀, 183.33 and 164.68 ppm, respectively) and S. mangiferae (18.93 and 16.93 ppm, respectively). Thymol and carvacrol had the highest effect on both insects. Furthermore, the effect of thymol and carvacrol at LC₅₀ values on some biochemical parameters of C. gnidiella was determined. Therefore, thymol and carvacrol from Thymus species are promising compounds that could be used as insecticides against the harmful insects C. gnidiella and S. mangiferae on mango inflorescences.