ACARICIDAL ACTIVITY OF SYZYGIUM CUMINI L. FRUIT EXTRACTS AGAINST TETRANYCHUS URTICAE KOCH (ACARI: TETRANYCHIDAE)

Abstract

The two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae) is an important polyphagous pest that infests many plant species world-wide. The acaricidal, ovicidal and repellent activity of different extracts of Syzygium cumini L. fruits were evaluated against T. urticae under laboratory conditions in the Department of Entomology, Hajee Mohammad Danesh Science and Technology University (HSTU), Dinajpur. The S. cumini fruit extracts were tested at 0.5, 1.0, 2.0 and 3.0% concentration. All the extracts had direct toxic and repellent effects on T. urticae. Mortality percentage was gradually increased with the increase of doses. The methanol extract showed the highest mortality (96.87%) of adult females followed by ethanol (91.66%) at 3% concentration. The LC50 values of methanol, ethanol, acetone and water extracts for adult females were 0.202, 0.281, 0.375 and 1.694, respectively and for eggs were 0.233, 0.255, 0.290 and 2.516, respectively. In the repellency test, all extracts showed repellency effects and significantly decreased the number of eggs on treated bean leaves. The methanol extract was found more effective as repellent against adult females of T. urticae followed by ethanol, acetone and water extracts ether causing reduction in egg production per female by 96.73, 94.03, 92.50 and 85.0%, respectively. In persistence test, extract of methanol showed highest mortality (41.66%) at 1 hour after treatment followed by ethanol (38.33%), acetone (35.00%) and water (28.33%). The lethal concentration effects of the extracts fade within two or three days. The result suggested that extracts of S. cumini has acaricidal activity against T. urticae, and the methanol and ethanol extracts are the most efficient.