Coconut Rhinoceros Beetle Infestation Discovered on Guam
Thursday, September 20, 2007 Mangilao, Guam
Last week, Aldrin Manapat and James Thomas Hollingsworth caught a very large, unusual looking beetle near the old Fujita Hotel site near the beach at Tumon Bay. The beetle was given to Brent Tibbatts at the Division of Aquatic and Wildlife Resources, which is part of the Guam Department of Agriculture who in turn sent it to be identified by Aubrey Moore, an entomologist at the University of Guam. According to Moore, the specimen is a female coconut rhinoceros beetle, Oryctes rhinoceros. This insect has not previously been collected on Guam and it is a major pest of coconuts and other palms, including betelnut. This beetle occurs naturally in many parts of Asia, including the Philippines, and it has been accidentally introduced to Palau, Samoa and Australia.
Adult beetles damage palms by boring into fronds before they open. When the fronds do open, they appear to have triangular sections cut out of them. Severe attacks by rhino beetles may result in the death of coconut palms. Immature beetles, referred to as grubs, feed on decaying wood and other plant material. They like to feed inside dead coconuts which are still standing.
During this past week, teams from the Department of Agriculture and the University of Guam have surveyed the island to find the rhino beetle infestation. They looked for beetles and the distinctive feeding damage caused by adults. It appears that the infestation is currently limited to Tumon Bay, all the way from the Hilton to Gun Beach. Survey teams found more than fifty coconut palms damaged by rhino beetles and they collected grubs at three locations. No adult beetles were seen.
This morning, Department of Agriculture officials met with University entomologists to discuss eradication of the rhino beetle before it spreads to other parts of the island and causes more damage. Eradication means killing all of the rhino beetles currently on Guam. Paul Bassler, Director of the Guam Department of Agriculture, says that “Successful eradication depends on us responding to this new threat without delay.” During the eradication program, grubs will be controlled by removal of breeding sites such as coconut stumps and rotting vegetation from the Tumon Bay area. At the same time, adult beetles will be trapped using a powerful attractant called an aggregation pheromone.
The public is asked to help in this effort by doing the following:
- If you find a rhinoceros beetle adult or grub outside of the Tumon area, please report it to the Plant Inspection Station at 475-1427. The adult is a very large beetle with a horn on the top of its head, and the grubs white, C-shaped, and have pink dots on their sides. Fact sheets and images of the coconut rhinoceros beetle and the damage it causes can be found online at:
- To prevent moving beetle eggs, grubs, and adults to other parts of the island, do not remove dead or rotting plant material from Tumon Bay.
FOR FURTHER INFORMATION, PLEASE CONTACT:
Aubrey Moore, Ph.D. Entomologist College of Natural & Applied Sciences University of Guam 303 University Dr. Mangilao, Guam 96923, USA Telephone (office): (671) 735-2086 Telephone (lab): (671) 735-2141 Telephone (home): (671) 653-5151 Telephone (cell): (671) 686-5664 Fax: (671) 734-4600