Field Incidence on Brontispa longissima (Gestro), an Invasive Pest of Coconut

The Coconut Leaf Beetle, Brontispa longissima (Gestro) (Coleoptera: Chrysomelidae) is one the most serious pests of coconut palms. This study was aimed to investigate the field incidence of Brontispa longissima infestation at Department of Agricultural, Parit Botak, Batu Pahat, Johor. B. longissima were collected from infested coconut and other palms and reared in the laboratory at MARDI, Serdang under ambient condition. The field incidence on the common varieties of coconut especially matag, pandan, tagnanan and other palms, oil palm were assessed. There was a significant difference in the mean percentage of leaf damage among palm varieties in the field (P<0.05). The pandan variety had the highest (40.93 +/- 0.91) mean of percentage leaf damage compared to matag (38.92 +/- 0.90), tagnanan (33.64 +/- 0.86) and oil palm (0 +/- 0.00). There was a significant (P<0.05) interactions between varieties and month on percentage of leaf damage in the field. The damaged incidence was highest in March and that the damage on pandan leaf was significantly (72.55 +/- 2.05) higher on matag (70.03 +/- 2.16), tagnanan (55.68 +/- 2.96) and oil palm (0 +/- 0.00).