The effect of four botanical volatile oil against aphid (Aphis gossypii) and mealybug pests (Phenacoccus solenopsis). A toxicological and chemical composition study

Given the economic damage caused by cotton mealybugs Phenacoccus solenopsis, (P. solenopsis) and aphids Aphis gossypii (A. gossypii), it was a need to look for more acceptable and safe materials. Four local plant extracts were assessed Ocimum basilicum, Origanum majorana, Pipper nigrum, and Schinus terebinthifolius represented by their volatile oils, against these two pests in the laboratory, with the following LC50 values for each applied volatile oil extract against aphid and mealybug 1938.05, 7391.33, 674.81, 5548.65, 644.45, 4383.52, 727.88, and 6735.62 ppm using the four previous extracts respectively. The highest mortality percentage was 50.0 and 49.3% for pipper nigrum, while the lowest percentage was for O. basilicum with 36.2 and 31.2% against P. solenopsis and A. gossypii, respectively. The oils that gave the highest mortality percentages pipper nigrum and Origanum majorana were analyzed using GCMS technique revealed the existence of major compounds belonging to the terpenoids chemical group, which have a noticeable role in the process of controlling these pests.