Eucalyptus weevil facts for kids
Quick facts for kids Gonipterus scutellatus |
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| Scientific classification | |
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| Phylum: | |
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Curculioninae
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Gonipterini
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| Genus: |
Gonipterus
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| Species: |
G. scutellatus
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| Binomial name | |
| Gonipterus scutellatus Gyllenhal, 1833
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Gonipterus platensis Marelli, 1927 |
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The Gonipterus scutellatus is a type of weevil. It belongs to the weevil family, Curculionidae. People often call it the eucalyptus snout beetle, the eucalyptus weevil, or the gum tree weevil. This insect eats and lays its eggs on Eucalyptus trees. It originally comes from Australia.
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What Does It Look Like?
This weevil is mostly greyish-brown. It has a lighter band across its body. It grows to be about 13 millimeters long. It looks very similar to a close relative, Gonipterus gibberus. Both share the same common names.
The young weevils, called larvae, are yellowish-green. They have black marks on their bodies. You can tell them apart from G. gibberus larvae by three dark green stripes on their bellies.
Where Does It Live?
The gum tree weevil is native to Australia. This is where Eucalyptus trees naturally grow. However, the weevil has spread to many other parts of the world.
You can now find it in countries like China, Kenya, and South Africa. It has also spread to Brazil, Chile, and the United States. In Europe, it is found in France, Italy, Portugal, and Spain.
What Does It Eat?
Gum tree weevils only eat Eucalyptus trees. These trees are their only "host plants." This means the weevil needs eucalyptus to live and grow.
Some types of eucalyptus trees are more likely to be attacked. These include Eucalyptus camaldulensis and Eucalyptus globulus. Other common targets are Eucalyptus maidenii, Eucalyptus punctata, Eucalyptus robusta, Eucalyptus smithii, and Eucalyptus viminalis.
Life Cycle of the Weevil
Adult female gum tree weevils lay about 200 eggs. They lay these eggs in groups of about ten. Each group is inside a grey capsule. These capsules are stuck to the top or bottom of eucalyptus leaves.
The eggs hatch after about a week. The tiny larvae then start eating the leaves and young shoots. They grow bigger by shedding their skin three times. After this, the larvae drop or crawl to the ground. They then burrow a few centimeters deep to change into pupae.
The whole life cycle, from egg to adult, takes about seven to eleven weeks. This depends on how warm it is. In places like Mauritius, there can be about four new generations of weevils each year. They can breed all year long. In South Africa, there are usually two generations. The adult weevils spend the winter months resting.
Why Is This Weevil Important?
In Australia, the gum tree weevil is not a big problem. This is because it has natural enemies there. These enemies help keep its numbers in check.
But in other countries, Eucalyptus trees were brought in from Australia. The weevil's natural enemies are not present in these new places. This means the weevil can cause a lot of damage.
Adult weevils mostly eat leaves and the soft bark of twigs. The larvae also mostly eat leaves. If there are too many weevils, they can cause shoots to die. This can lead to new shoots growing from the trunk or branches. If the trees lose their leaves many times, branches can split and die. Sometimes, even whole trees can die.
To control the weevil, a tiny wasp called Anaphes nitens has been introduced. This wasp is from Australia. It is a "biological control" agent. This means it helps control pests naturally. The wasp lays its eggs inside the weevil's eggs, stopping them from hatching.
This method has worked well in many places. In Mauritius, the number of gum tree weevils dropped a lot in just two years. It has also been successful in Italy, France, and Spain.
See also
In Spanish: Gonipterus scutellatus para niños
