Evaluation of different plant extracts against the Asian citrus psyllid Diaphorina citri (Hemiptera: Liviidae)

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, was also 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 registered System. The average values of the treatments were compared by the Tukey test (P less than or equal to 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.