Immigration and activity of Oryctes rhinoceros within a small oil palm replanting area.
Pheromone traps were used to monitor the immigration and activity pattern of adults of the rhinoceros beetle (Oryctes rhinoceros) within a 4.5 ha replanting block in an oil palm estate in Sepang in Selangor, Malaysia, from 1996 to 1999. Trapping started after about 5 months after replanting. The relationships of the trap captures with the heap population, palm damage, rainfall, and moon phases were also studied. Infestation of the block occurred almost simultaneously with replanting. The core region of the block was infested between month 4 and 7 after completion of felling and chipping. Female beetles were trapped more at the fringes than in the core of the replanting block. There was a relationship between the number of adult females trapped (at about 40-60 days before monitoring the population in the heaps) and the number of second instar larvae. There was an increase in the flight activity of the beetle during wet weather. Male beetles were more active during the full moon. Cumulative captures of each individual trap were related to the damage levels of adjacent palms. A high proportion (92%) of females captured in the traps were gravid, with a mean of 16 eggs per female. The results suggest that adult populations immigrate from adjacent mature plantings. This information can be exploited for more effective pest control. From authors' summary. KEYWORDS: TROPAG | Elaeis guineensis | pest insects | Oryctes rhinoceros | migration | biology | plantations | Elaeis | regeneration | South East Asia | Malaysia | Selangor.