Rhinoceros beetle in oil palm: symptoms and control
The rhinoceros beetle, Oryctes rhinoceros, is the main pest of young oil palm. It breeds in rotting trunks and wood, then bores into the unopened spear of the palm. Its signature is a new frond that opens with V-shaped cuts. Freshly replanted estates are the most exposed, because a pile of old trunks is the perfect nursery.
Knowing the beetle
The adult is 40 to 50 millimetres long, dark brown to black, with a small horn on its head. It flies at night and is drawn to lamps. The female lays in decaying organic matter: dead oil palm or coconut trunks, sawdust heaps, rotten wood, refuse and animal dung. The grubs grow inside the heap for months before emerging as beetles that fly off in search of a spear to bore.
Signs of attack
The adult enters at the base of a young frond and eats the soft tissue at the growing point. The bore hole itself is often hidden; what shows is the result one or two months later, when the frond opens with "cut marks in a V-shaped pattern". If the growing point is destroyed the palm can no longer make leaves, and dies.
The Ministry of Agriculture's guidance names young palms on replanted land as the most at risk; bearing palms can be attacked too. A 2025 field study by INSTIPER in North Sumatra looked at exactly those age classes: immature palms of two and three years and first-year bearing palms.
Control: start with the breeding sites
Sanitation
The Ministry puts sanitation first: "clearing every breeding site". Trunk piles, sawdust and rotting wood are removed or destroyed. At replanting, how the old palms are felled matters: a 2026 INSTIPER study in Labuhan Batu Selatan found lower beetle populations and less damage where the old trunks were felled and buried than where they were felled and chipped, at one site in one season, so treat it as a lead rather than a rule.
Cover crops
The same guidance recommends a cover crop on replanted land to bury the trunk remains that would otherwise serve as nests, so the beetle has a harder time finding somewhere to lay.
Pheromone traps
The beetle's aggregation pheromone is ethyl 4-methyloctanoate, which draws males and females alike. The Ministry's design is a 15-centimetre PVC pipe two metres tall with the pheromone hung near the top opening and two kilograms of sawdust at the bottom, ten traps per hectare, checked and replaced monthly. Another page from the same directorate says "2 to 3 traps per hectare", and its 2023 coconut guidance gives "1 to 2 sachets per hectare" replaced every three months; the dose differs between guides, so follow the local extension officer.
Metarhizium anisopliae
This green fungus infects the grubs in their nest. The Ministry's dose: 50 grams per breeding site of 1 by 1 by 0.5 metres, or a sawdust trap box of the same size with 25 grams of fungus, five boxes per hectare, reviewed every three months. A Gadjah Mada University study on coconut in Kulon Progo (2009 to 2010) found 265 of 281 grubs in treated nests infected, and damage to new fronds fell from 4.73 percent in the control to 1.08 percent with pheromone alone and 0.65 percent with pheromone plus Metarhizium. Oryctes baculovirus is the second biological agent, released through ten infected beetles per hectare.
Questions people ask
- Does the rhinoceros beetle attack mature palms?
- It can, but the real losses are among young palms on replanted land. A mature palm has enough fronds to shrug it off; a seedling or an immature palm does not.
- Are pheromone traps enough on their own?
- No. Traps catch adults already on the wing while the grubs keep growing in the nest. The best results in the Gadjah Mada study came from sanitation, traps and Metarhizium together.
- Does Metarhizium kill adult beetles?
- Its main target is the grub in the nest, though the Ministry notes adults can be infected too. That is why the fungus goes on the debris heap, not on the palm.
In the game
In Sawit Simulator the beetle lives on "debris", a number from 0 to 100 on every block. Chopping forest leaves 55; burning leaves 10, or 40 when what burned was an oil-palm block, since charred trunks feed beetles too. Debris rots very slowly, almost four years for chopped forest, and all that time beetles breed in it: two per point of debris, doubling roughly every twelve days, and hopping to neighbouring blocks that also hold a nest.
As in the field, the game's beetles attack only seedlings and immature palms; mature palms are left alone. The answers are the same too: a sanitation crew clears 60 points of debris at once and is the only cure that lasts; a pheromone trap kills beetles for 120 days; Metarhizium slows breeding for 90 days. What is simplified: the game's cover crop holds a slope against landslides rather than burying nests, and the way old palms are felled makes no difference.
Sources
- Directorate General of Estate Crops, Ministry of Agriculture, SINTA: Kumbang Tanduk (quoting the 2010 guidance on major oil palm pests). In Indonesian. https://sinta.ditjenbun.pertanian.go.id/kumbang-tanduk/
- Directorate General of Estate Crops, Ministry of Agriculture, SINTA: Kumbang Oryctes rhinoceros (2 to 3 traps per hectare). In Indonesian. https://sinta.ditjenbun.pertanian.go.id/kumbang-oryctes-rhinoceros/
- Directorate General of Estate Crops, Ministry of Agriculture, Pengendalian Kumbang Oryctes rhinoceros pada Tanaman Kelapa, 1 August 2023. In Indonesian. https://ditjenbun.pertanian.go.id/pengendalian-kumbang-oryctes-rhinoceros-pada-tanaman-kelapa/
- Jurnal Perlindungan Tanaman Indonesia (Gadjah Mada University) 19(2), 2015, Tekanan Metarhizium anisopliae dan Feromon terhadap Populasi dan Tingkat Kerusakan oleh Oryctes rhinoceros. In Indonesian. https://journal.ugm.ac.id/jpti/article/view/17260
- AGROFORETECH (INSTIPER Yogyakarta) 4(1), 2026, Perbandingan Pengendalian Oryctes rhinoceros pada Kebun Kelapa Sawit Replanting dengan Sistem Tumbang Benam dan Tumbang Chipping. In Indonesian. https://jurnal.instiperjogja.ac.id/index.php/JOM/article/view/2399