Red palm weevil
Rhynchophorus ferrugineus
Figure 1. Red palm weevil adult intercepted in the UK on a gourd imported from Sri Lanka © Fera
Background
Rhynchophorus ferrugineus Olivier (Coleoptera: Curculionidae) is a highly invasive pest of
palms that can have a significant economic, environmental and social impact when
introduced into new geographical areas. It is the most important pest of date palm
(Phoenix dactylifera) in the world and a serious pest of coconut (Cocos nucifera). It is
native to southern Asia and Melanesia but since the 1980s it has rapidly expanded its
geographical range westwards. It reached Saudi Arabia and the United Arab Emirates in
about 1985, spreading throughout the Middle East and into Egypt. In 1994 it was detected
in Spain and in 1999 in Israel, Jordan and the Palestinian Authority Territories. It has since
spread widely in the Mediterranean region where the two main palm species of concern
are date palm and Canary Island date palm (Phoenix canariensis), the main crop and
ornamental species. It also attacks several other ornamental palms that are regularly
imported into Britain, such as chusan palm (Trachycarpus fortunei). It has devastated
ornamental palms in many areas of the Mediterranean, changing the landscape. The
European Commission has introduced emergency measures to prevent the further spread
of R. ferrugineus within the community.
Plant Pest Factsheet
Figure 2. Red palm weevil larva © Luigi Barraco Figure 3. Red palm weevil pupa © Luigi Barraco
Figure 4. Red palm weevil cocoon, consisting of
tightly woven fibres, removed from the base of a
dead palm, China © C. Malumphy
Figure 5. Red palm weevil adult on an adult hand
to indicate the size of the beetle, China © C.
Malumphy
Figure 6. Red palm weevil adult feeding damage to
palm foliage © 2003 International Palm Society
Figure 7. Collapsed palm due to red palm weevil
infestation, Italy © V. Martino - NPPO Campania
region
Figure 8. Red palm weevil larva (indicated by an
arrow) tunnelling inside the stem of a palm, Italy ©
G. Pesapane - NPPO Campania region
Figure 9. Palm with a broken apex due to red palm
weevil infestation, Italy © R. Griffo - NPPO
Campania region
Figure 10. Dying and dead Canary Island date
palms, Greece © C. Malumphy
Figure 11. Red palm weevil adult killed by an
entomopathogenic fungus, China © C. Malumphy
Figure 12. Dying Canary Island
date palm, Montenegro © C.
Malumphy
Figure 13. Dead and infested
palms in a park, Italy © C.
Malumphy
Figure 14. Pheromone trap for
monitoring red palm weevil,
China © C. Malumphy
In 2013, an outbreak of R. ferrugineus was found in Brittany, France, in plants imported
from Spain. In 2016 there were further findings in France on imported palms, in Normandy
and Auvergne-Rhône-Alps. These findings suggest that, despite emergency measures,
the pest is moving in trade. In October 2016 a large number of R. ferrugineus larvae and a
few adult beetles were confirmed inside a round-leaf fountain palm (Saribus (= Livistona)
rotundifolia in Essex. The palm had been imported from Italy in March 2016. The infested
palm was destroyed and the surrounding area surveyed by the Plant Health and Seeds
Inspectorate. A single live adult R. ferrugineus had been previously intercepted in
association with a gourd imported from Sri Lanka in 2014.
Geographical Distribution
Rhynchophorus ferrugineus is present in the following regions and countries: Europe and
Mediterranean: Albania, Algeria, Croatia, Cyprus, Egypt, France, Greece, Israel, Italy,
Jordan, Libya, Malta, Morocco, Palestinian Authority Territories, Portugal, Slovenia, Spain,
Tunisia and Turkey. It may also be more widespread in North Africa. Asia: Bahrain,
Bangladesh, Cambodia, China, Georgia, India, Indonesia, Iran, Iraq, Japan, Jordan,
Kuwait, Laos, Lebanon, Malaysia, Myanmar, Oman, Pakistan, Philippines, Qatar, Saudi
Arabia, Sri Lanka, Syria, Taiwan, Thailand, United Arab Emirates, Vietnam and Yemen.
Caribbean: Aruba, Curaçao and Netherlands Antilles. Oceania: Australia, Papua New
Guinea, Solomon Islands, Vanuatu, Western Samoa.
Host Plants
Rhynchophorus ferrugineus feeds primarily on palms (Arecaeae) although it has
occasionally been found feeding on non-palm hosts such as Saccharum officinarum (sugar
cane). Palm hosts include: Areca catechu (betel nut palm), Arecastrum romanzoffianum
(Queen palm), Arenga saccharifera (sugar palm), A. pinnata (sugar palm), Borassus
flabellifer (toddy palm), Borassus sp. (palmyra palm), Brahea armata (Mexican blue palm),
Butia capitata (pindo palm), Calamus merrillii (rattan), Caryota cumingii (fishtail palm), C.
maxima (giant mountain fishtail palm), Chamaerops humilis (dwarf fan palm), Cocos
nucifera (coconut), Corypha utan (Synonyms C. gebang and C. elata, gebang palm), C.
umbraculifer (talipot palm), Elaeis guineensis (oil palm), Howea forsteriana (Kentia palm),
Jubaea chilensis (Chilean wine pam), Livistona australis (cabbage tree palm), L.
decipiens (ribbon fan palm), L. chinensis (Chinese fan palm), L. saribus (serdang palm), L.
subglobosa, Metroxylon sagu (sago palm), Oneosperma horrida, O. tigillarium (nibong
palm), Phoenix canariensis (Canary Island date palm), P. dactylifera (date palm), P.
sylvestris (Indian date palm or silver date palm), P. theophrasti (Cretan date palm),
Roystona regia (synonym Oreodoxa regia, royal palm), Sabal umbraculifera (pygmy date
palm), Saribus (aka Livistona) rotundifolia (round-leaf fountain palm), Trachycarpus
fortunei (Chusan palm) and Washingtonia spp.. ‘Susceptible species’ as listed in EU
measures are underlined above, but it should be noted that the weevil has been found on
other hosts.
Description
Adults are large, about 35 mm long and 10 mm wide, although they can be up to 42 mm
and 16 mm wide (Figs. 1 and 5), with a long rostrum (an elongate projection from the front
of the head), characteristic for the weevils. They are reddish-brown in colour with variable
dark markings on the pronotum (section of the body behind the head). Eggs are whitish-
yellow, smooth, shiny, cylindrical, with rounded ends, slightly narrower at the anterior end,
and about 3 mm long and 1 mm wide. Larvae (Fig. 2) are legless, with a creamy-white
body and brown hard head capsule, and grow up to 50 mm in length. The wing cases, legs
and other appendages can be seen on the pupa (Fig. 3). Pupation occurs in an elongate
oval, cylindrical cocoon made of fibrous strands, about 40 mm in length (Fig. 4). The
cocoons are remarkably tough.
Biology
All life stages may be spent inside the host palm. Each adult female deposits between 200
to 300 eggs in separate holes or cavities on the host plant. Eggs hatch in two to five days,
and larvae bore into the interior of the palms (Fig. 8), feeding on the soft succulent tissues,
discarding all fibrous material. The larval period ranges from 36-78 days (average 55 days)
depending on temperature and host species. Pupation occurs in a fibrous cocoon and the
adult weevils (Fig. 5) emerge 2-3 weeks after pupation. Thus the life cycle is completed in
about 4 months.
Dispersal and Detection
It is very difficult to detect R. ferrugineus in the early stages of infestation. Generally, it is
detected only after the palm has been severely damaged. Early symptoms of attack
include egg laying notches; cocoons inserted into the base of the palms; an eccentric
growing crown; holes at the base of cut palms; symptoms resembling those caused by
lack of water such as wilting, desiccation and necrosis of the foliage (Fig. 6); tunnelling
within the stems and trunk. Larvae and adults destroy the interior of the palm tree, often
without the plant showing signs of deterioration unless damage is severe. Hollowing out of
the trunk reduces its mechanical resistance, making the plant susceptible to collapse (Figs
7 and 9). In most cases, attack on Phoenix and other palms leads to the death of trees
whatever their size (Figs 10, 12 and 13). Visual examination allows detection of symptoms
but cannot determine if there are larvae and adults present inside the trunk. Pheromone
traps (Fig. 14), acoustic detection or infrared systems can be used to detect this pest.
Economic Impact
Rhynchophorus ferrugineus is a major economic pest of coconut palm, date palm, oil
palm, sago palm and a range of ornamental palms. Severely attacked plants exhibit a total
loss of foliage and rotting of the trunk, which eventually results in the death of the tree. It
has proved to be a devastating pest in many parts of the Mediterranean where large
numbers of mature palms in urban areas and parks have had to be removed as infested
palms may collapse and are a danger to the public. It can also have a detrimental social
impact in areas such as the Middle East where the date palm is closely associated with
culture and religion.
Advisory Information
UK garden centres and nurseries need to be aware of the risk of R. ferrugineus when
purchasing palm trees. In 2007, the EU passed emergency measures to reduce the risk of
red palm weevil being introduced into the EU and being spread within the EU
(2007/365/EU updated by 2007/365/EU). The emergency decision includes a list of
‘susceptible plants’, i.e. species of plants that are known to be hosts of R. ferrugineus (see
‘host plants’ section above); the measures only apply to palms with a main stem diameter
over 5 cm. Any ‘susceptible plants’ imported from outside the EU must either: come from a
country where R. ferrugineus is not known to occur OR have been grown in an officially
established pest free area OR have been grown within complete physical protection at a
registered site where they have undergone official inspections every 3 months and
immediately prior to export. Any plants being moved in the EU must have been grown in a
member state whether R. ferrugineus is not known to occur OR throughout their lives in an
official pest free area OR grown for 2 years in a site with complete physical protection and
have been inspected by officials every three months. UK importers should ensure that
palms they purchase and sell comply with the measures above, but also note that other
palms may also be infested, and that all palms should be monitored for any signs of
infestation. The UK is currently seeking Protected Zone status against this pest.
Suspected outbreaks of Rhynchophorus ferrugineus or any other non-native plant pest
should be reported to the relevant authority:
For England and Wales, contact your local APHA Plant Health and Seeds Inspector or
the PHSI Headquarters, Sand Hutton, York. Tel: 01904 405138
Email: planthealth.info@apha.gsi.gov.uk
For Scotland, contact the Scottish Government’s Horticulture and Marketing Unit:
Email: hort.marketing@gov.scot
For Northern Ireland, contact the DAERA Plant Health Inspection Branch:
Tel: 0800 200 7847 Email: planthealth@daera-ni.gov.uk
For additional information on UK Plant Health please see:
https://secure.fera.defra.gov.uk/phiw/riskRegister/
https://www.gov.uk/plant-health-controls
https://www.ruralpayments.org/publicsite/futures/topics/contact-us/
https://www.daera-ni.gov.uk
Authors
Original: Chris Malumphy and Helen Moran (Fera) Nov 2009
Update: Chris Malumphy (Fera), Dominic Eyre and Helen Anderson (Defra) Feb 2017
© Crown copyright 2017
mailto:planthealth.info@apha.gsi.gov.uk
mailto:hort.marketing@gov.scot
mailto:planthealth@daera-ni.gov.uk
https://secure.fera.defra.gov.uk/phiw/riskRegister/
https://www.gov.uk/plant-health-controls
https://www.ruralpayments.org/publicsite/futures/topics/contact-us/
https://www.daera-ni.gov.uk/
