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The Scientific World Journal
Volume 2012 (2012), Article ID 651416, 7 pages
Research Article

Impacts of Horticultural Mineral Oils and Two Insecticide Practices on Population Fluctuation of Diaphorina citri and Spread of Huanglongbing in a Citrus Orchard in Sarawak

1Faculty of Agriculture and Food Sciences, Universiti Putra Malaysia Campus Bintulu Sarawak, Jalan Nyabau, 97008 Bintulu, Sarawak, Malaysia
2Faculty of Resource Science and Technology, Universiti Malaysia Sarawak, 94300 Kota Samarahan, Sarawak, Malaysia
3Centre for Plant and Food Science, University of Western Sydney, Locked Bag 1797, Penrith New South Wales 2751, Australia

Received 11 November 2011; Accepted 1 February 2012

Academic Editor: Aurelio Gómez-Cadenas

Copyright © 2012 Stephen Chan Teck Leong et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Aspects of the incidence and spread of the citrus disease huanglongbing (HLB) in relation to the vector Diaphorina citri population fluctuation were studied from January 1999 to December 2001 seasons in a 0.8 ha citrus orchard at Jemukan (1° 33′N, 110° 41′E), Southwest Sarawak in Malaysia. In relation to insecticide and horticultural mineral oils (HMOs) use, levels of HLB infection rose quite rapidly over the next 3 years in the unsprayed control and less rapidly in the other treatments such as imidacloprid, nC24HMO, and triazophos/cypermethrin/chlorpyrifos. Levels of HLB as determined by Polymerase Chain Reaction (PCR) were 42.2%, 9.4%, 11.4%, and 22.7%, respectively. The effects of nC24HMO and conventional pesticides on the citrus psyllid population and parasitoids in citrus orchard were also determined.