Rhynchophorus ferrugineus
- Insect with chitinous carapace
- Crawling, flying
- Agricultural and forest pest
The palm weevil is a beetle from the weevil family and is now widespread worldwide. In the Mediterranean region, it threatens all palm trees, especially coconut, sago and date palms, and has caused millions of dollars of damage. It is considered one of the most damaging insects.
The palm weevil is not a disease vector.
More data
Class: Insects
Other names: Red palm weevil, Indomalayan palm weevil, Malayan palm weevil.
Size: 3.0 to 3.5cm
Weight: Variable
Age: 1 to 5 years
Appearance: Brownish-red in colour, underside and legs black.
Feeding type: Larva: Herbivore
Food: Soft and moist plant tissue in the growing area of the palm tree
Distribution: Worldwide
Original location: Southeast Asia
Sleep-wake rhythm: Diurnal
Habitat: Palm trees
Natural enemies: Squirrels
Egg laying: Approx. 300 eggs inside the palm crown
Social behaviour: Colony formation of up to 300 beetle larvae
Threatened with extinction: No
- Originally, the palm weevil is a native beetle of the Thai island of Kho Samui. Since the 1980s, it has spread to Europe and Africa via the Mediterranean region. Since its immigration to these areas, it is considered the largest weevil to be found there.
- Through the import of palm trees from Southeast Asia, the palm weevil was introduced to Spain, Greece, France, Italy and Portugal, where it has since caused millions in damage. The palm weevil is the biggest threat to palm vegetation in the Mediterranean region today.
- On the Balearic Islands of Mallorca and Ibiza, the palm weevil was discovered in 2006; 10 years later, about 4% of the palm trees had been destroyed, which corresponds to about 11’700 mainly date palms. The problem is of such magnitude that any infestation must be reported immediately to the authorities and the pest control with highly toxic insecticides begins. Infested areas are separated from the rest of the palm tree and disposed of exactly as prescribed. If the entire palm tree has to be removed due to an official measure, costs of approx. 1,000 Euros are incurred. The follow-up costs for the purchase of a new palm amount to approx. 2,000 Euros.
- Although the palm weevil originally comes from the tropical zone, it can also survive the winters in temperate latitudes. Its well-developed flying ability promotes its spread and reinfection of palm plantations.
- The palm weevil prefers to attack freshly cut or weakened palms. The beetle can "smell" the sweet sap emerging from the cut surface from up to 20 km away. Here the female beetle lays about 300 creamy-white shiny eggs, from which the larvae hatch after 2 to 5 days.
- The larval stage, which lasts up to three months, is the actual feeding stage of the palm weevil. During this time, a colony of up to 300 larvae destroys a palm tree.
- At the tip of the trunk in the area of the leaf bases (palm heart), the larvae eat their way through the tissue up to one metre into the growth zone. They feed on the sap and fibres of the palm tree.
- The infestation is not visible for a long time in this phase, but when the first visible damage occurs, the tree is already lost without salvation. The leaf fronds die, the eroded growth cone (palm heart) can no longer form new leaves.
- After the 3-month larval stage, the larva forms an oval, elongated pupa chamber made of plant fibres. After about 14 to 21 days, the beetles hatch.
- Early detection of infestation is very difficult. It can also vary greatly from species to species of the palms. Experts agree that although highly toxic insecticide cocktails are used preventively and directly in case of infestation (inoculation technique), there is no guarantee that the infested palm can be saved.
- For early detection of larval activity, a sensor (bioacoustic method) is inserted into the interior of the palm tree to perceive the feeding and digestion sounds of the insects. Experts can hear the pests nestled in the trunk smacking when they put their ear to the trunk.
- The larva of the palm weevil is eaten raw, smoked, roasted or steamed as sago worm by the indigenous peoples of Southeast Asia (Malaysia, Vietnam, Papua New Guinea). Sago worms are a delicacy and an important source of protein.
In which area does the pest occur?
The area of application determines which products are recommended to control this pest.
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