Ethanolic crude extracts of neem ( Azadirachta indica ), oregano ( Lippia graveolens ), guava ( Psidium guajava ), Cleopatra mandarin ( Citrus reshni ) and garlic ( Allium sativum ), were evaluated in doses of 50 and 500 ppm. Oregano oil, 2 and 4%, mixed with Tween detergent as emulsifier, also was evaluated. To determine the efficiency of these extracts either as repellents or bioinsecticides, against the Asian citrus psyllid Diaphorina citri ; insects found on the plants were counted at 24 and 48h after the application; dead insects were registred only at 48h after application. The data obtained were analyzed using the statistical package SAS® System. The average values of the treatments were compared by the Tukey test (P<0.05). The best treatment as repellent at 24h and 48h after the application was the garlic extract at a dose of 50 ppm, showing the 84.37% and 87.50%, of insects repelled, respectively. The best treatment as bioinsecticide was oregano oil 4%, showing a mortality of 70.31% of the Asian citrus psyllid. The results obtained show a promissory alternative to use the oregano oil in a program of integrated pest management.
Alonso et al. (Wed,) studied this question.