The Action of Gelam (Melaleuca cajuputi) Stem Crude Extract as Natural Insecticide for Camponotus Sp.

摘要

Treatment of old historical wooden houses with synthetic preservative lined with chemical pesticide were known to cause hazards to human and the environment. Gelam tree crude extract was investigated in this study to explore its potential to repel wood damaging carpenter ants in order to reduce the use of hazardous pesticides and attack on the timber by wood boring insects. The crude extract from Gelam tree stem (Melaleuca cajuputi) was extracted by sequential extraction using hexane, dichloromethane and methanol. The repellent activity was tested at 20% w/v concentration using World Health Organization (WHO) recommended method on ant repellent testing for 3 hrs with 15 min’s interval. All the extracts showed significant repellent activity on the tested Camponotus sp. ants. The toxicity activity on Camponotus sp. was determined by using 10% w/v concentration of crude extract mixed with honey. Toxicity activity of methanol extract (84.3%) showed the high toxicity percentage against Camponotus sp. The LT50 recorded for Camponotus sp. tested with hexane, dichloromethane and methanol crude extract were 19.11 hrs, 11.89 hrs and 9.43 hrs respectively. This study indicated that M. cajuputi stem has potential to be further studied and developed as natural insecticide against carpenter ants for the application on wooden buildings.