Red that kills: the palm trees disease

The leaves that reach up to 6 meters in length and a long stem are the ones that grow more in the heights than a four-storey building, the Palm of the Canaries is highly appreciated by those who like to look up and shade on sunny days . It is quite resistant, adapting to the rainy regions and with much wind, as is the case of coastal zones.

So, you can not find more stores in the world like these in the city of Porto in places like in the Botanical Garden or in Jardim do Passeio Alegre.

These incredible plants are endangered by an insect that does not reach 5 centimeters: the red beetle. Also known as palm beetle or palm beetle, it is a reddish-colored beetle insect that has an Asian origin and a life cycle in which all its phases coexist.

The insect acts as follows: adult beetles feed on the palm leaves, creating minor damage. The problem is even the placement of their eggs, which when they hatch, release the larvae of voracious appetite. They eat the younger leaves of the plants and then create holes in the plant and eat their meristem, the central part of the palm tree that produces new leaves. With this region severely affected, infected trees are unable to produce their respiratory organs and eventually die.

In the Botanic Garden, the large Palm of the Canaries that is at the entrance is already almost without leaves, although it still has life. Joana Tinoco, a garden biologist, told Porto Gardens that the plant is treated monthly with a product to control the disease. "Let's hope she survives. Her meristem is still good, so she still has the ability to regenerate, to produce leaves. If it bursts and can produce new leaves that remain in the plant and make it grow, it still has some survival rate, if it does not produce more leaves we lose it completely, "he says.

Within a single plant, a beetle can produce several generations, being possible to find individuals of each stage of development of the insect in the palm trees. In the city's climate, the plague requires three to four months to complete the egg-to-adult cycle, so there may be at least three generations of beetles per year. If we consider that the female can put between 300 to 400 eggs, the capacity of reproduction is brutal.

A palm tree may be infested by the red beetle and does not manifest any symptoms for several months, which makes its treatment and control difficult. Thus, it is very common to see dead palm trees through the city.

Written by: Matheus Rabelo
Translated by: Rita Lopes
Photos by: Francisca Rehbein and Júlia Aguiar

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