Rhinoceros Beetle - What is happening?

The coconut rhinoceros beetle recently arrived in Solomon Islands and is causing serious damage to coconut palms on Guadalcanal, Savo, North Malaita and Ngela. Many people are asking, “What is happening to control it?”

We mentioned last week that everyone can help by cleaning up and destroying the breeding sites; the beetles love piles of rotten vegetation especially dead, decaying, palms. Around town and anywhere else, dead palms should be cut down and destroyed as they are perfect breeding places. Palms which are not yet dead (they still have a growing spike) might recover and perhaps they can be left in place in case they do recover, but as soon as they are clearly dead they too should be destroyed. 

Figure 1. Young oil palm damaged by coconut rhinoceros beetle.

Oil palm too is being attacked (see picture) and GPPOL, with support from Biosecurity Solomon Islands, is implementing a range of methods to try to control the pest. On young palms they are using a pesticide to kill beetles attacking the palm, but this is only suitable before the palm is ready to produce pollen and fruit. On tall palms they are using an injection technique but this is expensive and not suitable for wide scale use.

Perhaps the most interesting work that is happening at GPPOL is the work to find a virus disease to kill the beetle. The same beetle in Fiji, Tonga and Samoa was controlled in the 1960s by a virus disease found in Malaysia, but from work done by researchers in New Zealand it seems the strain of beetle we have is not affected by the virus strain used in the South Pacific. Some other strains of the virus have been imported and some have successfully killed adult beetles in the laboratory. Work is ongoing to identify a virus strain that will control the beetle we have in Solomon Islands.

Figure 2. Adult beetle being infected with virus at the GPPOL laboratory.

Currently GPPOL staff at Ngalimbiu (Jaydita Pue and Martha Lela) are running tests to try to extract a virus strain that is effective in Solomon Islands . Soon they hope to begin releasing infected adults into the plantation. Initially this will be on a small scale but soon a new laboratory provided by the Sime Darby project (parent company of GPPOL) will arrive and it is hoped to step up the numbers considerably. This project is collaborating with another project supported by the New Zealand government to find new diseases. These projects, Biosecurity Solomon Islands and local stakeholders will be meeting in Honiara 23-25 January to plan activities for the next three years. The results of this meeting will be reported next week.

Work is also ongoing at GPPOL and at the Ministry of Agriculture and Livestock research laboratory at Henderson with a fungus disease that is known to kill the adults and larvae. The MAL Research Division is looking at new ways to bulk up the quantities of the fungus and GPPOL staff are looking at improved methods of releasing it into the beetle environment.