End of fascination

1988/04/01 Elhuyar Zientzia Iturria: Elhuyar aldizkaria

• Botanika

The Leukaena tree has been fascinating for forestalists in tropics and subtropics. This tree, regardless of its rapid growth, resists constipation and also fixes nitrogen. Governments and peasants have considered it very suitable for both revegetation plans and recovery of marginal land. It is a very abundant source of wood and wood. Therefore, leuco has been very cultivated in extensive plantations of tropics and subtropical.

However, thousands of leukocytes begin to get sick and die. This tree, considered free from insect attacks, is the victim of a bug called Heteropsylla cubana.

This chicharro looking insect was first detected in Florida in 1983. With the help of the winds he arrived in Hawaii in 1984, west of Samoa in 1985 and Indonesia, Papua Guinea Berri, Australia, Malaysia and Thailand in 1986. India could be the next step and the last Africa.

Although adult insects are harmful, nymphs are the most harmful. Nymphs feed only on new shoots and secrete a conflictive matter that prevents the development of other shoots. Txistu is believed to inject toxins into the tree. After the attack of the insects, the trees are weakened and become very sensitive to any disease. In droughts and poor soil trees the problem increases.

Adequate ways to control the pest have not yet been found. Chemical pesticides, in addition to being ineffective in such a jumping insect, are expensive and dangerous to the user and the environment. It has been thought about the use of exotic insect predators such as the Curinus coeruleus beetle. But be very careful when introducing alien species into a biotope, so that the hunter does not eventually become a pest.

The long-term solution could be the planting of varieties of attacked leuconia or other nitrogen-fixing trees (Calliandra, Sesbania and Gliricidia).

However, this story has its essence, as it perfectly shows the dangers of monoculture. Especially when using an exotic species.