Apply control measures if 3-5 beetles occur per ha up to 2 years after planting, and 15-20 beetles per ha thereafter.īIOSECURITY Vigilance is needed at seaports and airports against hitchhiking beetles. A fungus, Metarhizium anisopliae, from the Philippines is also used. Today, the key agent is a virus ( Oryctes rhinoceros nudivirus - OrNV) originally from Malaysia. Research into management of Oryctes started in the Pacific islands in the 1960s. Spread is on the wing, they are stronger flyers, and aboard ships and aircraft. They do not eat the frass from the tunnels instead, they drink the sap that comes from tunnelling. The beetles are nocturnal, flying to the tops of coconuts where they use their mandibles, horn and strong forelegs to tunnel into the crowns. Females live about 9 months, and lay about 50 eggs males live about 5 months. They are black with horns - those of the female often shorter than the male (Photos 9-12). The two pupal stages last 25-40 days.Īdults remain in the ground for 2-3 weeks and then chew their way out. The last stage makes a hollow where it feeds, lining it with liquid faecal material, and then pupates. There are three stages lasting 80 to 200 days (depending on quality of the diet), with the third stage up to 100 mm long and 20 mm diameter.
The C-shaped larvae or grubs are white then creamy with brown heads (Photo 8). Logs and stumps of many other kinds of trees are also hosts (Photo 7). Oval eggs (3.5 x 4 mm) are laid one at a time, 5-15 cm, below the surface of moist organic materials, such as sawdust, manure, compost and garbage heaps, or above ground in tunnels, debris in axils of coconut fronds, in still-standing but dead and rotten coconut palms, and in the rotten ends of fallen coconut trunks (Photo 6). Holes in the base of the fronds may be obvious when beetle populations are high (Photo 5). When the leaves unfold the damage is seen as V or wedge-shaped areas missing from the leaflets (Photos 1-4). The adult beetle does the damage, boring into the crown of coconut palms, cutting across young fronds and flowers.
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