The effectiveness of neglected Malaysian plants as biological repellent against Malayan Black Bug (Scotinophara coarctata Fabricius) / Siti Faridah Amin

Average rice yield loss damage by various insect pests toward paddy plants in Asia is reported about 20%. One of the major insect that commonly attacking paddy plants and caused direct damage to the yields is Scotinophara coarctata (Fabricius) or also known as Malayan black bug. Malayan black bug belongs to Hemoptera order has a black head, collar and cicatrices; reddish to brown abdomen, yellowish brown antenna and reddish brown legs with tibiae and tarsi. This bug has bad smell and regarded as noisome insects. The Scotinophara coarctata is one of the sap feeding insect and it is difficult to manage. This bug will attack the paddy plant at all stages of its growth and cause disease called bug burn. Nowadays, the fastest and effective ways to control pest in crops used is by using synthetic organic and chemical insecticides. But, it may cause damage to the environment, ecology, pest resurgence, pest resistance and effects on non-target organisms. The bio-pesticides give many advantages to the plants, human, ecology and not harmful compared to chemical pesticides. The repellent activity of five selected plants which were Piper betel, Murray a koenigii, Annona muricata, Citrus microcarpa and Pandanus amaryllifolious had been tested by using vial bioassay, through four different concentrations were tested in this experiment which were 5%, 10%, 15%, and 20% as well as water as control. The result showed that all the treatments are able to repel this bug. The most effective concentration for all treatment is C4 (20%) for Piper betle, Murraya koenigii, Annona muricata and Pandanus amaryllifolious while for Citrus microcarpa the most effective concentration is C 2 and C 3 (10% and 15%). The effectiveness of the repellence are in the following sequence Piper betle > Pandanus amaryllifolious > Annnona muricata > Murayya koenigii > Citrus microcarpa.