Insecticidal activity and chemical composition of plant essential oils against cotton mealybug, Phenacoccus solenopsis (Tinsley) (Hemiptera: Pseudococcidae)
Mohamed Elhosieny Mostafa, Naglaa Mohamed Youssef and Anwaar Mohamed Abaza
Ten plant essential oils were extracted and tested for their toxicity against the adult females of cotton mealybug, Phenacoccus solenopsis (Tinsley) (Hemiptera: Pseudococcidae) under laboratory conditions. Mortality varied according to the essential oil type and the delivered dose (ppm). The most remarkable toxic essential oils after 24h and 72h of treatment were Thymus vulgaris followed by Mentha longifolia, and Cyperus articulates essential oils. The LC50 values were 29.03, 34.32 and 54.69 ppm, respectively after 24h while after 72h of treatments were 15.04, 24.93 and 29.21 ppm, respectively. Gas Chromatography-Mass Spectrometry was used to analyze the most potent essential oils and identify the most active ingredients.