Monday, November 5, 2012

An unfriendly, squeaking beetle

The list of animals and plants living in a particular area constantly changes with time with new species appearing and others disappearing. Some species arrive on their own natural while others are imported by man and wittingly or unwittingly released in new areas.

During the past decade or so we have been hearing about several insect species that appeared in the Maltese islands. The Asian tiger mosquito is a nuisance and carrier of dangerous diseases. The red palm weevil which also appeared in the Maltese islands a few years ago has decimating many palm trees.

Another alien species that is causing great damage is the mulberry long-horned beetle. This species originated in central Africa. It was first noticed in Malta in 2000. When it first arrived it laid its eggs in black mulberry trees (siġra tat-tut) and later on white mulberry trees (siġra taċ-ċawsli) and has destroyed many old trees.

It has also been recorded on fig trees which are related to the mulberries.

In Malta the mulberry long-horned beetle does not seem to have any natural enemies and is free to reproduce unhindered. The larvae live in deep tunnels which they dig in the branches and are not easily reached by insecticides. The adults are mainly nocturnal and to be effective spraying has to be applied during the night. The adult beetle is large and can reach a size of more than four centimetres. 

The antennae areas long as the rest of the body. When picked up it makes a squeaking noise which probably distracts predators.

The mulberry long-horned beetle has been given the Maltese name ħanfusa tal-qrun twil tat-tut. It probably arrived in Malta as a larva or pupa with wood or logs imported for the wood industry. 

It has not yet spread into the rest of Europe except for parts of France and we should do our best not to let it leave the Maltese islands to spread havoc in neighbouring countries. 

This article was published in The Times 31.10.2012

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