General Information

Damage is usually effected by feeding adults. The adult beetles bore through stem bases of frond into the heart of the palms to feed on the vegetative bud and young leaves. The damaged young leaves eventually grows out and exhibits V-shaped notches on fronds. Severely attacked palms with damaged hearts will die; leafless though can remain standing.

Feeding damage may reduce fruit production, kill both seedlings and young and old palms, and discourage replanting. Boring holes also provides entry points for lethal secondary attacks and/or infection by the palm weevil Rhynchophorus (where present) or pathogens. In Ivory Coast (Africa), the adults of O. boas (and also O. monoceros) have been reported to be carriers of the nematode Thelastoma pterygoton.

Oryctes boas breeds in manure heaps or decomposing vegetation but not in rotting wood. Population peaks during dry seasons and diminish in the wet season. All stages are present throughout the year, resulting in overlapping generations.

It has recorded feeding on other economically important commercial crops such as coconuts, bananas, sugarcane, papayas, sisal, pineapples, taro and date palms.

Distribution

Central and Southern Africa (tropical regions) including Madagascar, Yemen, Saudi Arabia.

Detection and Inspection

ADULT
Large, shiny, reddish-brown to black in colour. Approximately 3.5 – 4.5 cm long. The males have large rhinoceros-type frontal horn. Nocturnal insects and feed during nighttime. Strong fliers.

Average lifespan is 6 to 12 weeks. Females can live up to 16 weeks and lay about 40-50 eggs.

PUPAE
Fat and brown in colour measuring 4 cm long. Occurs in rotting plant debris with the larvae. Pupal period is about 3 weeks. Upon emerging from the pupal cases, the adults tunnel their way out of the breeding sites into the open. decaying plant matter that the larvae feed on. Larval development duration is 2 months with three larval instars.

LARVAE
Soft white, wrinkled grubs measuring 6 cm in length. Usually found curled up in a C-shaped position in the moist, decaying plant matter that the larvae feed on. Larval development duration is two months with three larval instars.

EGGS
Laid singly in manure heaps or decaying plant matter. Oval, dirty white and measure about 3.5-4 mm long. The larvae hatch after 10-12 days.

Prevention and Control

PHYTOSANITARY
Eggs are difficult to detect via visual inspection. Only the larger larvae beetles may be detected. Source germplasm from pest free areas, and ensure sanitation from sourcing to shipping. The import of germplasm material (seeds, pollen, tissue culture) must be accompanied by an import permit issued by or on behalf of the Director-General of Agriculture for Peninsular Malaysia (including Labuan), or the Director of Agriculture for Sabah, and a phytosanitary certificate issued by an authorised official from the country of export. The import conditions are available upon request from the Plant Biosecurity Division Malaysia. All consignments are subjected to inspection by the Agricultural Department prior to clearance by Customs. Germplasm material imported from high risk areas should be sent for third country quarantine before arrival onto Malaysian shores. The import of alternative host plant parts e.g. Phoenix dactylifera from infested areas should be enquired with DOA.

CULTURAL CONTROL AND SANITARY METHODS
A single beetle is capable of flying long distances and attacking many palms during its lifespan. Cultural control is the most feasible method. The recommended methods includes planting palms at the same time, at a close regular spacing so that a continuous canopy of foliage develops (isolated palms and palms of irregular height are more susceptible to attacks); cutting down and destroying dead palms; and remove plant debris and manure at the base of the palms. Other methods involve pheromone trapping, physical removal of adults and killing the beetles in the bore holes with a pointed wire.

Further reading

1. Appanah, S; Sim, H C and Sankaran, K V (2007). Developing an Asia-Pacific Strategy for Forest Invasive Species: The coconut beetle problem- bridging agriculture and forestry. In: Report of the Asia-Pacific Invasive Species Network Work-Shop. 22-25 February 2005. Ho Chi Minh City, Vietnam. 36 pp.
2. Bedford, G O (1980). Biology, Ecology, and Control of Palm Rhinoceros Beetles. Ann. Rev. Entomol., 25: 309- 339.
3. Beetle Identification App (Beetles of the World) (2015). Oryctes boas image. Url: http://beetleapp.com/sampleanimal- images/
4. CABI CPC (2014). Oryctes boas (rhinoceros beetle). Url: www.cabi.org/cpc/
5. EPPO Global Database (2015). Oryctes boas. Url: https:// gd.eppo.int/taxon/ORYCBO/distribution.
6. Hill, S D (2008). Pests of Crops in Warmer Climates and Their Control. Springer: UK. p. 270 & 272.
7. USDA-APHIS (2014). The Coconut Rhinoceros Beetle. URL: https://www. aphis.usda.gov/wps/portal/aphis/ourfocus/ planthealth?1dmy&urile=wcm%3apath%3a%2 FAPHIS_Content_Library%2FSA_Our_Focus%2FSA_ Plant_Health% 2FSA_Domestic_Pests_And_ Diseases%2FSA_Pests_And_Diseases%2FSA_ Insects%2FSA_Coconut_Rhino_Beetle%2F.
8. Van Emden, H (2013). Handbook of Agricultural Entomology. Wiley-Blackwell: UK. 334 pp.