The palm weevil Rhynchophorus ferrugineus is one of two species of snout beetle known as the red palm weevil, Asian palm weevil or sago palm weevil. The adult beetles are relatively large, ranging between long, and are usually a rusty red colour—but many colour variants exist and have often been classified as different species (e.g., R. vulneratus). Weevil larvae can excavate holes in the trunks of palm trees up to long, thereby weakening and eventually killing the host plant. As a result, the weevil is considered a major pest in palm plantations, including the coconut palm, date palm and oil palm.
Originally from tropical Asia, the red palm weevil has spread to Africa and Europe, reaching the Mediterranean in the 1980s. It was first recorded in Spain in 1994, and in France in 2006. Additional infestations have been located in Malta, Italy (Tuscany, Sicily, Campania, Sardinia, Lazio, Marche, Puglia and Liguria), Croatia and Montenegro. It is also well established throughout most of Portugal, especially in the South. It also has established in Morocco, Tunisia, and other North African countries. The weevil was first reported in the Americas on Curaçao in January 2009 and sighted the same year in Aruba. It was reported in the United States at Laguna Beach, California late in 2010 but this was a misidentification of the closely related species, R. vulneratus, and it did not become established.
Larvae of Rhynchophorus ferrugineus are considered a delicacy in Southeast Asian cuisine. In some regions, however, larvae farming is strictly prohibited to prevent the potential devastation of plantation crops.
Taxonomy
Primarily due to the existence of numerous color forms across their ranges, the taxonomy and classification of red palm weevils has undergone a number of changes in understanding and circumscription. As such, the information in the literature should be viewed as a compilation of data which may apply to both species, depending primarily upon the biogeography; accordingly, the vast majority of publications presumably do refer to R. ferrugineus rather than vulneratus, as the former is by far the most widely invasive. The most recent genus-level revision in 1966 recognized two species of red palm weevil, ferrugineus and vulneratus, and for decades these were interpreted as separate taxa. A genetic study in 2004 concluded that vulneratus was not distinct from ferrugineus, and treated them as synonyms, a view that was accepted until 2013, when yet another genetic study came to the opposite conclusion, based on more comprehensive geographic sampling. Accordingly, the "red palm weevil" species that appeared in the US was vulneratus rather than ferrugineus, though the latter is the invading species in all of the other global introductions.
Distribution
Range
The native range of this species is considered to include Bangladesh, Cambodia, China, India, Japan, Laos, Pakistan, Philippines, Sri Lanka, Taiwan, and Vietnam; records from Indonesia, Malaysia, Myanmar, Singapore, and Thailand largely or exclusively refer to R. vulneratus. R. ferrugineus has now been reported and confirmed from Albania, Algeria, Aruba, Bahrain, Bosnia and Herzegovina, Croatia, Curaçao, Cyprus, Egypt, France (incl. Corsica), Greece, Israel, Italy (incl. Sicily and Sardinia), Jordan, Kuwait, Libya, Malta, Monaco, Montenegro, Morocco, Oman, Palestine, Portugal (incl. Madeira), Qatar, Saudi Arabia, Slovenia, Spain (incl. the Balearic and Canary islands), Syria, Tunisia, Turkey, and United Arab Emirates. Records from Australia, Papua New Guinea, Samoa, the Solomon Islands, and Vanuatu have not been confirmed and are likely to be specimens of R. bilineatus, a closely related species indigenous to the region.
CABI ISC range list
Africa
absent from Algeria
Djibouti
Egypt
Libya
Mauritania
Morocco
Tunisia
Nigeria
Asia
Bahrain
Bangladesh
Cambodia
China since 1997, first detection in Guangdong. The model of Ge et al 2015 predicts a wide area of invasion based on climate suitability, throughout the south, north to the east and west to central China. Fujian Guangdong since 1997 Guangxi Hainan Jiangsu Tibet Yunnan Zhejiang Georgia Hong Kong India Andaman and Nicobar Islands Andhra Pradesh Assam Bihar Daman and Diu Goa Gujarat Karnataka Kerala Maharashtra Meghalaya Odisha Tamil Nadu Tripura Uttar Pradesh West Bengal absent from Indonesia Iran Iraq Israel Japan Honshu Kyushu Ryukyu Islands Jordan Kuwait Lebanon Laos absent from Malaysia Myanmar Oman Pakistan Philippines Qatar Saudi Arabia absent from Singapore Sri Lanka Syria Taiwan Thailand Turkey United Arab Emirates Vietnam Yemen Socotra