Palm Tree Disease (THE RED PALM WEEVIL) - Explanation by an expert

Description:

Part 1 - The Red Palm Weevil

The red palm weevil (Rhynchophorus ferrugineus) is a curculionids beetle, a native of Southeast Asia. Since the early 80s and in some 10 years, it has invaded much of the palm trees on the Arabian peninsula, where there are numerous date palms, Phoenix Dactilifera. The jump to Europe has come with the massive importation of palm trees from Egypt; it was found for the first time in the province of Malaga in 1994. The Spanish authorities have intervened to try to eliminate the parasite, but apparently with little success.

The red beetle is fatal to the Canary Island, date and coconut palm trees; but there are many more species of palm trees that can be attacked by this insect.

The adult red beetles are reddish, 2.5 to 3 cm long. The female may deposit 200 to 350 eggs around cracks in the trunk or at the base of the leaves by digging tunnels within. Cuts in the branches result in a sap, which attracts the female; as a result it is best to prune only in winter.

The red beetle attack in general is followed by the death of the tree, as by three generations they reach the inside of the palm. A small proportion of adult beetles will leave the tree to find other trees to colonize; but the vast majority stay put until the tree is destroyed and completely dead.

To date, there is no way of detecting the parasite early, which presents a serious obstacle to the adoption of measures to fight the beetles and prevent the full grown palm trees from being infected; So preventive treatments are recommended to stop this dangerous beetle attacking in the first place.

The Agriculture department is withdrawing infected palms, crushing and burning them, to prevent the possible spread of the plague; but sadly there is a waiting list of over 15 months. So this action is too late because from each infected palm trees 2000 new beetles will be looking to infest a new palm tree.

Part 2 - The Red Palm Weevil

As we wrote in the previous issue the red weevil (Rhynchophorus ferrugineus) is a beetle that attacks the palms so ravenously, that sadly they end up killing them if no action is taken.

In our company we are in the forefront in the fight against this terrible plague applying the two products recommended by the Department of Agriculture, Fisheries and Food. In addition we undertake direct action using the technique of surgery (to be discussed in the next issue) getting some spectacular results, recovering palms from the dead within a few months by alternating these products and techniques.

In fact there are not two insecticides, but three, but one of them is 45% Phosmet and authorized only for professional use in palm nurseries and should not be applied in either private or public gardens because of its high toxicity.

Of the two authorized insecticides, one is a chemical, imidacloprid and the other biological, namely Nematodes Entomopatógenos.

The time of treatment is directly related to the insect's activity. In the coldest months (December, January and February) there are virtually no flights of adult and more treatments can be applied. The insect begins its activity in March-April and the population is at its highest between June and November.

In future issues, we will talk in more detail of these two products. The method of applying them is quite different, though the chemical can be purchased at any nursery or garden, or agricultural cooperatives and stores.

The biological product is much more complex with respect to low temperatures; it needs to be applied with a tank sprayer specially prepared or modified. Still it is more to be recommended, as it is harmless to humans, pets, plants, etc, and in our experience is more effective than the chemical, even so we recommend that you alternate between them.

Part 3 - The Red Palm Weevil

In the previous issue of this magazine, we wrote about the methods of chemical and biological fight that the Department of Agriculture, fisheries and food recommend in their implementation schedules against this scourge. Last issue we discussed our preferred chemical and biological treatments. This issue we will focus on palm surgery.

The red weevil's name can seem a little flashy or even funny; and it always awakens a little curiosity why the name ‘surgery' has been given to what is a manual technique applied to plants, trees and palm trees.

We now turn to more detail on what the palm surgery goes into. The first thing to evaluate is the status of the pest in the palm. A palm at the onset of an attack is not the same as a palm that is almost dead, and there are stages in between. But even if you see a great advance of the plague, you may still find the tip of the palm is in a state that can be recovered.

If it is decided to implement this technique, we must consider that it is as a cleansing of this insect that it is located around the tip and this is where we must act. So we start to clean up from top to bottom removing leaves, pellets and debris in the tree cup where we see the red palm weevil insects.

You always have to work around the tip, but without damaging it; because if we go deep into it, we could kill the palm tree unintentionally. Then we apply a chemical insecticide into all the galleries that we see, in order to reach deeply into the weevil larvae. Depending on the state of the tip, it will recover or not.

Articles submitted to BRITCHAT by JUANMA MARTINEZ.  Mes Que Jardines. Torrent.  Near Valencia Spain.