essential oil (eo) of origanum vulgare l. was hydrodistilled and analysed using gas chromatography-flame ionization detection and gas chromatography-mass spectrometry. the monoterpenes, carvacrol (61.2%), -terpinene (9.6%), thymol (8.3%), and p-cymene (5.7%) were identified. oil-in-water nanoemulsion was prepared and characterized from the eo through a green procedure. botanicals had a remarkable mosquitocidal and effectively inhibited acetylcholinesterase activity of aedes aegypti. the nanoemulsion at 40 ug/ml caused 100% adult and larval mortality after 12 h. at 80 ug/ml, percentage mortality caused by eo products ranged between 55.11-100% for larvae, and 63.0 -100%. for adults after 24 h exposure, lc50's ranged between 13.2 and 75.7 ug/ml against larvae, and between 10.1 and 36.0 ug/ml against adults. the lethal time (lt50) decreased with nanoemulsion, eo and carvacrol. test products were safe towards the non-target aquatic species, gambusia affinis and diplonychus indicus. results recommend test botanicals as natural alternatives to control ae. aegypti.