Pest control: Palm Tree Infestation by the Red Palm Weevil.
Index
· Introduction
· Biology
· Symptoms
· Methods of control and prevention
· Report of treatments
· Biological control of pest infectations
· Conclusions y reflections
· Examples of Palm Tree recuperation
· Guarantees and references of Ciudad Verde
The Red Palm Weevil or curculionido ferruginoso (Rhynchophorus ferrugineus Olivier) is a weevil originating from the tropical regions of Asia and Polynesia that has been continuously spreading throughout other subtropical and temperate regions and colonising different species of palm trees. It is one of the main infestations affecting the palms of the Far East, the Middle East and North Africa. It was introduced into Spain at the time of grand scale importation of Phoenix dactylifera from Egypt. First detected in 1995 in Almuñecar (Granada), the disease has since spread all along the coastal fringe of the Mediterranean and through the Canary Islands, where it is devastating great numbers of palms.
In Spain it primarily attacks the Canary Palm (Phoenix canariensis) followed by the Date Palm (Phoenix dactylifera). At present, the following palm tree species could be infected by the attacked: Areca catechu, Arenga pinnata, Borassus flabellifer, Butia capitata, Calamos merillii, Caryota maxima, C. cumingii, Cocos nucifera, Corypha gebanga, C. elata, Elaeis guineensis, Livistona decipiens, Metroxylon sagu, Roystonea regia, Ph. theophrasti, Ph. sylvestris, Sabal umbraculifera, Trachycarpus fortunei, Whashingtonia robusta y W. filifera.
Insects of this family are characterised by a beak shaped prolongation of the head, by distinctly elbowed antennae, and by their very characteristic reddish colourisation (ferruginoso). The male differs from the female by having a brush like structure on its ‘beak’.
The adults can fly long distances and climb well; they are easily able to climb from the ground to the crown of palm trees.
The female lays her eggs both in the insulated cavities of purposely made wounds at the base of the leaves and in the soft tissue inside leaf buds at the top of the trunk near the start of the leaves (the crown of the palm); it is therefore difficult to spot them.
The larva grows inside the humid soft fibres of the palm, on which it also feeds. It is between 3 and 5 cm long, legless and of squat aspect. Its head is a ruddy brown colour. These larvae can excavate cavities of more than a metre in length.
The Pupa is found at the base of the palms, both inside and outside the trunk, protected
In the Spanish Mediterranean region the complete life cycle from egg to adult takes between three and four months which means up to four generations a year.
The adults colonise the palms as they fly between them. They prefer diseased trees that have pruning wounds or are weak from recent transplantation.
Young centre leaves with leaflets that have been eaten producing serrated edges and are drooping and/or sickly looking. In the more advanced stages of infestation the crown breaks and is felled by the wind. Really bad attacks cause the crown to dry up and bring about the death of the tree. When the affected leaves are shed, and they fall quite readily, the open cavities at the base, made by the larvae in their last stage of development, can be observed. The pupal cocoons give off a characteristic acidic odour.
METHODS OF CONTROL AND PREVENTION
Given the characteristics and dangerous nature of the infestation it is vital that it is rapidly detected. To get a reliable diagnosis of the condition of a palm, a specialist company or professional, qualified and able to advise on treatments or methods of prevention should be consulted.
Nowadays there are chemical products licensed for preventative and curative treatment, which when combined with biological treatments using entomological pathogenic nematodes can offer good results in the control and prevention of infestations.
Pheromone traps are also a very effective biological method of reducing the weevil population.
Wounds in the palm trees are to be avoided. Pruning should be carried out during cold spells of the year, when the adult insects are least mobile. This way, the spread of disease to places outside the immediately affected area can be reduced.
Use of scar covering resin or pastes over prune wounds is recommended as is the application of insecticides to the cut areas.
In areas already affected, it is advisable not to undertake new plantings of Phoenix canariensis or dactylifera because they are weak and vulnerable during their settling in period.
For the most effective control of Red Palm Weevil Infestation it is vitally important that new outbreaks are detected as soon as possible and that everyone co-operates.
The above advice is based on the recommendations of la Junta de Andalucía (The Regional Andalusian Authority)
A REPORT ON THE TREATMENTS CARRIED OUT BY CIUDAD VERDE s.l.u. IN THE FIGHT AGAINST INFESTATIONS OF THE RED PALM WEEVIL (Rhynchophorus ferrugineus O.) THROUGHOUT VARIOUS REGIONS OF THE COSTA DEL SOL (MÁLAGA)
Dr. Mábel Hidalgo Berutich
Technical Division of Ciudad Verde
Introduction
Ciudad Verde is a company that has been principally devoted to gardening (design, construction and maintenance of gardens) since 1994 and our area of operation is centered mainly in the Benalmádena, Torremolinos and Fuengirola areas, where we look after private gardens, hotel gardens and community gardens. As well as garden maintenance we also treat plant pests and diseases and we are authorized by and officially registered for this work by the Regional Andalusian Authority (el Centro Oficial de Servicios Plaguicidas de la Junta de Andalucía.)
Our activities relating to the Red Palm Weevil began in 2005 when we sent informative leaflets to our private, hotel and community garden clients. The first treatments began in February 2006 at a hotel in Benalmádena Costa, where employees of the local authority, (la Junta de Andalucía) cut down a badly affected Phoenix dactylifera palm.
We are now carrying forward the fight against the Red Palm Weevil with information campaigns and by carrying out diagnosis and treatments on more than 4,000 palm trees in the towns of the Costa de Sol and in other Andalusian towns. In 2010 the Infestation was declared to be of “Public Concern” which means that preventative, and where appropriate, curative treatments are obligatory to safeguard the heritage of our country’s Palm Trees.
Fieldwork methods
We have made an Ongoing File for each client, where we record the level of infestation, the species of palm and its size, the date, location, record of any pruning etc.
The diagnosis or state of the palm is assessed by Biologists and Technical Experts is carried out by means of observation of visible external symptoms and direct inspection of the crown of the tree, using ladders and other methods.
Treatments are carried out every 40-50 days. We use authorized products, applying them by spraying the crown. Since November 2007 we have also been carrying out biological treatments using live entomological pathogenic nematodes. Both chemical and biological forms of treatment are programmed by the Senior Technician to be alternated or combined in a programmed schedule of applications specifically designed for each individual case. We have also carried out mechanised removal of affected areas using a chainsaw with the aim of promoting the growth of new shoots. Another method we use where palms are badly affected is Endoterapia Vegetal ® a plant injection method, whereby a pistol like mechanism inserted into the tree trunk dispenses a controllable flow of treatment solution. Cleaning or sanitisation of the crown by chainsaw and by hand in the most extreme cases. The installation of traps with luring pheromones is also proving to be an effective method of capturing numerous adults and fertile females. These methods may be combined to a technical criteria and are known as “Integrated Treatment". All these methods are undertaken and compared and examined in various different recognised Centres of Research and Investigation, but up to the present no one treatment has been found to eliminate the infestation completely.
Biological control of pest infestations
Our company, Ciudad Verde s.l.u , always concerned for the environment and the quality of our service, is introducing, as one of its phytosanitary treatments,a BIOLOGICAL TREATMENT which uses live entomological pathogenic nematodes (Steinernema carpocapsae) and their associated bacteria (Heterorhabdis bacteriophora).
These organisms are authorised for use by the Andalusian Authority’s regional ministry of Agriculture (la Junta de Andalucía, Consejería de Agricultura ) for use in the Biological Control of Pests and Diseases.
The nematodes are juvenile parasitic insects that can survive several months without food whilst they actively search out hosts, which they normally enter by the natural orifices (i.e. mouth, anus etc). Once inside they release bacteria which cause the death of the host insect by septicaemia (a generalised infection) in the space of about two days.
The research using pathogenic nematodes for treatment of the Red Palm Weevil has been widely studied by La Estación Phoenix and at other research centres. The conclusions drawn from the results of the research is that this biological treatment is an efficient tool for controlling infestations, and given its persistence in the palm, is preferable to a chemical product.
Ciudad Verde is a distributor for these nematodes which come from the prestigious laboratory of Biobest and so, as well as using them in their treatments, they are able to supply any organisation or individual interested in the product (Supply of Plants and Materials). The traps and their pheromones also complement biological treatments and originate from the same laboratory.
These nematodes should be applied in quantities of 20-25 thousand per palm and may be mixed with the authorised chemical product, and applied at least 8 times per year.
Palm System
A permanent system whereby a fixed treatment dispenser made up of high resistance nylon tubes, is inserted into the tree. It is quick to install (using Slip Lok connectors and nozzles). It can withstand UVA rays and use of the “bicycle pruning method”. This system allows easy treatment of the palms substituting the use of the lance, for a quickly made connexion directly into the lower part of the palm ready for treatment from our range of products.
Conclusions
After five years of treating the Palm Trees in our area we are able to draw the following conclusions:
The use of up to date preventative treatments on healthy Palm Trees is a fundamental procedure for avoidance of attack by the Red Palm Weevil. We have personally verified that in badly affected areas, healthy species of canarias remain disease free when systematic prevention measures are taken.
Curative treatments have been effective in 75% of cases. It is most important that that the method of application by spraying is carried out using adequate equipment (high reach lances etc.) and that the crown and the base of the leaves are well drenched (30-40 litres per tree). The application of the biological treatment using nematodes must also be meticulous, given that it involves the use of living creatures and must be used according to the manufacturer’s instructions. We say all this having seen that bad practice is fairly common in such treatments nowadays. In many cases treatments are carried out by ‘gardeners’ and companies that are neither qualified or authorized to do so, including official bodies such as the Town Halls. It is important to stop this bad practice as it produces inefficient treatments and an ensuing loss of credibility in the products used and ability to save specimens.
- The regular frequency of treatments is very important, and we have found that in our area the disease has no “winter pause”- weevils can be seen flying about in January and February!
- The use of integrated treatments using a combination of methods, chemical, biological (entomological nematodes), mechanical (removal of damaged areas) and including traps to catch the adults seems to be the most effective method of treatment and prevention, provided that it is carried out in a professional manner.
We are open to any suggestion for co-operation in the fight against this disease.
Some concrete examples of Palm tree recuperation.
Torremuelle O-31 (Benalmádena): A palm Tree re- sprouting after treatment. Notice how the palms in the background are disappearing.
Some concrete examples of Palm Tree recuperation:
Hotel Sunset Beach (Benalmádena) : first site of the Red Palm Weevil in Benalmádena.
Undergoing treatment since February 2006.
Now with all the palms saved.
Hotel los Álamos (Torremolinos): undergoing treatment since May 2007. The Town Hall wanted to cut these trees down in June 2007.
Inspection by crane in June 2007. Present condition.
Torremuelle O-31 (Benalmádena): Re-growth after treatments.
April 2007.
February 2008. September 2008.
Calle Colima (Benalmádena): Palm undergoing integrated treatment since October 2007, when it had no crown.
Condition in February 2008. Present condition.
· Arroyo de la Miel, (Benalmádena): Two palms that was to be cut down in February 2007, but which instead underwent integrated treatment.
Avenida La Leala, present condition. Calle Adaja, Present condition re-growth after 3 treatments (4 months)
· Calle Valdepeñas (Alhaurin de la Torre): undergoing treatment.
Condition in June 2008. Condition in September 2008.
· Palm Euromarquet hypermarket parking in Mijas Costa.
In integrated treatment since May 2009 Recovering (Nov. 2010)
· Palmera en Churriana
Integrated treatment since December 2009 State a year later
GUARANTEES AND REFERENCES FOR CIUDAD VERDE
*REGISTERED COMPANY No. 29/076 OFFICIALLY APPROVED FOR PUBLIC HEALTH AND AUTHORISED TO CARRY OUT APPLICATIONS OF ENVIRONMENTAL PESTICIDAL AND PHYTOSANITARY PRODUCTS.
*TREATMENT CARRIED OUT BY SPECIALISED STAFF UNDER THE SUPERVISION OF A SENIOR TECHNICIAN (BIOLOGY) OFFICIALLY LICENSED WITH A TECHNICAL QUALIFICATION FOR THE APPLICATION OF ENVIRONMENTAL PESTICIDES.
*PRODUCTS USED ARE DULY REGISTERED FOR HEALTH AND ARE ENVIRONMENTALLY ACCEPTIBLE AND /OR HARMLESS TO PEOPLE, DOMESTIC ANIMALS AND PLANTS.
*CONTROL OF AND STRICT ADHERENCE TO STANDARDS OF SAFETY AND HYGENE AND RESPECT FOR THE SURROUNDING ENVIRONMENT.
*PUBLIC LIABILITY INSURANCE
*CERTIFICATE HOLDER FOR DIAGNOSIS AND TREATMENTS.
*USE OF OFFICIAL MODEL CONTRACTS
REFERENCES FOR TREATMENTS CARRIED OUT (amongst others)
Ciudad Verde has been carrying out preventative and curative treatments against the infestation of the Red Palm Weevil to palms mainly in the areas of Torremolinos, Benalmádena, Fuengirola and Mijas Costa since February 2006.
Up until now we have obtained good results for our customers whose palms we treat according to the individual recommended cycle. We always use the latest authorised products.
They also hold references for the following works carried out:
- Diario Sur's Article about our treatments against the Red Palm Weevil (spanish)
- Diario Sur's Article about our treatments against the Red Palm Weevil in Tivoli World (spanish)
- Preventative treatment - Hotel Sunset Beach,
- Preventative treatment - Hotel Aloha Puerto,
- Preventative treatment - Hotel Sol Timor,
- Preventative treatment - Comunidad La Cizaña,
- Preventative treatment - Comunidad Golf Garden Miraflores ,
- Preventative treatment - Comunidad Benalmar Playa,
- Preventative treatment - Comunidad Laderas del Mediterráneo,
- Preventative treatment - Mancomunidad Diorama,
- Preventative treatment - Comunidad Urbanización Hacienda Las Chapas,
- More than 500 trees in private gardens.
