Journal of Oil Palm Research Vol. 21 (2) December 2009, p. 667-674
EFFECT OF Bacillus thuringiensis, TERAKIL-1® AND TERACON-1® AGAINST OIL PALM POLLINATOR, Elaeidobius kamerunicus AND BENEFICIAL INSECTS ASSOCIATED WITH Cassia cobanensis
A laboratory study on the effect of Bacillus thuringiensis (Bt) product, Terakil-1® and Teracon-1® on oil palm pollinating weevil, Elaeidobius kamerunicus and beneficial insects such as predators and parasitoids was studied to evaluate the safety and specificity of Bt product against non-target organisms in particular the beneficial insects as compared to chemical. The male spikelets were sprayed with Terakil-1® and Teracon-1® at different doses, ranging from 3.7×107 cfu ml-1 3.7×1011 cfu ml-1 and 0.1124 μg ml-1 – 1124 μg ml-1, respectively. At five days after treatment (DAT), Terakil-1® and Teracon-1® being target specific at dose of C5, 3.7×1011 cfu ml-1 and 11.24 μg ml-1, resulted in 21% and 25% mortality of beneficial insects, respectively. Whereas, at seven DAT, Terakil-1® and Teracon-1® being a safe Bt products at dose of C5, 3.7×1011 cfu ml-1 and 11.24 μg ml-1, resulted in 22% and 23% corrected mortality of beneficial insects, respectively. Cypermethrin at 5.5% w/w as a chemical control led to 100% corrected mortality of beneficial insects at five DAT. As for oil palm pollinating weevil, E. kamerunicus, Terakil-1® and Teracon-1® being a safe and environmental-friendly products, each resulted in 26% and 33% mortality of E. kamerunicus at seven DAT at 100-fold higher dose than the recommended dose of C3, 3.7×109 cfu ml-1 and 11.24 μg ml-1. Whereas, at seven DAT, Terakil-1® and Teracon-1® being a safe Bt products at dose of C5, 3.7×1011 cfu ml-1 and 1124 μg ml-1, resulted in 14% and 16% corrected mortality of E. kamerunicus, respectively. At five to seven DAT, the mean mortality of the adult E. kamerunicus subjected to the five different doses, 3.7x107cfu ml-1 to 3.7×1011 cfu ml-1 and 0.1124 μg ml-1 – 1124 μg ml-1 of Terakil-1® and Teracon-1®, respectively was not significantly different at P=0.05 when tested using Duncan’s Multiple Range Test, implying that even at very high doses, Bt products were equally safe to the weevils. Cypermethrin was significantly toxic to pollinating weevils as compared to high doses of Terakil-1® and Teracon-1®. Unlike chemicals, B. thuringiensis, Terakil-1® and Teracon-1® were found to be safe for beneficial insects under the oil palm and is therefore recommended for integrated control of bagworm under oil palm.
KEYWORDS:* Malaysian Palm Oil Board,
P. O. Box 10620,
50720 Kuala Lumpur,
Malaysia.
E-mail: mnajib@mpob.gov.my