The so-called stem borer of moluccana koroi (Paraserianthes falcataria) has been identified as a bark-eating caterpillar, Indarbela quadrinotata Walker (Metarbelidae : Lepidoptera). The pest is polyphagous attacking many forest, shade and ornamental trees. Six new host trees were recorded for the first time. The pest has a single generation in a year. The peak infestation occurred during October- November. In 4-year old stands of P. falcataria, the mean percentage of trees infested ranged from 33.3 to 70.0 and the mean number of active larval holes per tree varied from 1.1 to 3.7. Unhealthy growing stock was most heavily infested.