The Minister of Ecological Transition, Fight against Climate Change and Territorial Planning of the Government of the Canary Islands, José Antonio Valbuena, and the president of the Cabildo of Lanzarote, María Dolores Corujo, have signed this Thursday the cooperation agreement between the two institutions for the execution of the plan to control and eradicate the plague of 'Diocalandra frumenti' or 'palm weevil' of the Phoenix canariensis of Lanzarote, which has a budget of two million euros divided equally between the two institutions.
Valbuena explained the need and urgency of putting this plan into operation since this plague “is threatening the Canary Island palm tree, a symbol of the Canary Islands for being an endemic species of our archipelago”. Thus, he explained that it is a long action that will begin with massive trapping based on pheromones, focusing first on the control of the plague and, subsequently, on the eradication of this.
The Minister of Ecological Transition announced that the Ministry intends to extend this project, first to Fuerteventura and, subsequently, to the rest of the archipelago, "so the knowledge generated in Lanzarote will serve as experience in the whole of the islands".
For her part, the president of the Cabildo of Lanzarote indicated that "this plan to recover the Canary Island palm tree in Lanzarote is vital given the seriousness of the problem and pointed out that, of the 60,000 palm trees registered on the island, more than 50% of them are affected by this plague whose propagation is favored by the scarcity of rain and the lack of an adequate substrate, which causes the palm tree to weaken and be attacked".
Corujo explained that "the ornamental practice of using palm trees on the roadsides has been corrected since it was a perfect breeding ground for the propagation of the insect and that the work of execution of the plan will begin in the palm groves of the south since they are the most affected".
The project to protect palm groves against 'Diocalandra frumenti' aims to increase the areas free of plague on the island and establish phytosanitary measures to prevent re-infection from highly affected areas, as well as reduce plague pressure and control it in those highly affected areas.
The plan also seeks to obtain data that allows the phytosanitary management of palm trees on the island, as well as raise awareness through training of involved agents, and the population in general, of the consequences that climate change may have on the phytosanitary status of the island's plant heritage. For this last, information campaigns will be carried out in schools and to professionals.
Before starting the action, a study of the situation of palm trees on the island has been carried out by the public company Gestión del Medio Rural de Canarias, which was divided into two phases. In the first, palm trees were analyzed in San Bartolomé, Tías and Yaiza, resulting in 80% of the inspected palm trees being affected by the plague, with about 51% of the analyzed specimens with a moderate degree of affectation, and the remaining 49% with serious and mild affectations in the same proportion. In addition, 100% of the inspected palm trees located in the coastal strip of these municipalities are affected.
In the case of San Bartolomé, 77.5% of the prospected palm trees show a moderate degree of affectation in 62.3% of the specimens. In Tías, the percentage of affected palm trees on the prospecting is 81.8%, with 55% of them with a moderate degree. Finally, in Yaiza, 79.61% of the palm trees are affected, 40% of them with a moderate degree of affectation.
Meanwhile, in the second phase, specimens were diagnosed in the municipalities of Tinajo, Teguise, Arrecife and Haría. Of the total number of palm trees prospected, 33% are affected and half of them have a moderate degree of affectation, while the levels of mild and severe affectation are present in the same proportion.
By municipalities, in Arrecife 95% of those inspected are affected, 68.4% of them with a moderate degree of affectation. In Haría, the total number of affected specimens is 23.5%, but 47% of them have a severe degree of affectation, so it is urgent to act to dimension the focus, avoid its expansion and eradicate it. In Tinajo the percentage of affected prospected palm trees is 27.2%, with 43.5% of them with moderate affectation. Finally, in Teguise the affected percentage is 14.81%, with 38.4% of them with a mild degree of affectation and 36.1% moderate.
The results obtained in the two reports describe a very dangerous situation for the phytosanitary status and the future survival of the Phoenix canariensis, so it is necessary to urgently apply measures to prevent the dispersion of the plague.
About the ‘Diocalandra frumenti’
The 'Diocalandra frumenti' is a small beetle —about five millimeters— that was detected for the first time in specimens of Canary Island palm tree in 1998 in Maspalomas, on the island of Gran Canaria. In the archipelago, its biological cycle occurs uninterruptedly throughout the year, completing from when it is an egg until it is an adult in about three months. In addition, its presence has been confirmed in all the islands except in La Graciosa and El Hierro.
The egg is not easy to see and has an oval shape, semi-transparent bright color with a size around one millimeter. The eggs are deposited by the females, through their ovipositor, in an isolated manner. The larvae when emerging are yellowish, without legs, elongated, segmented and with a hardened yellow-brown head, provided with strong conical mandibles. At the end of the larval phase, after a period of eight or ten weeks, it can reach a length of between six and eight millimeters in length.
Once the larva is created, it feeds on the internal plant tissue of the palm tree and as a consequence of this action leaves a series of internal galleries, causing in this stage the greatest damage to the palm tree that are noticeably visible. Thus, necrotic areas are seen at the base of the leaves that produce characteristic deformations. Even, if the necrosis is important, the leaves even fall in green.
