Weevils by Elissa and Julia

We live in Florida where the melaleuca tree is taking over our beloved Everglades. Melaleucas originate in Australia, but when some Americans brought these trees back to Florida, they started growing like crazy. As a result, the melaleuca overgrowth is choking out other native plants and destroying the habitat for the animals that call it home. To save the Everglades and its creatures, scientists introduced an Australian bug called a weevil. The weevil eats melaleucas and researchers hope that the bugs' feeding habits will slow down the habitat's takeover. Our question: Is the weevil slowing the spread of melaleuca trees in the Everglades?

What did we do?
We went to a location in the Everglades called "ground zero." This is where scientists first brought the weevil. From ground zero, the scientists have let the weevils spread out on their own. We then counted the number of weevils we saw and looked for the signs of damage to the melaleuca trees. Then we traveled four miles away into the Everglades to see if the weevil had spread there. We charted their positions using maps and a GPS (global positioning system) device. After counting weevils and inspecting tree damage at this site, we went another four miles in and checked again.

What did we find out?
We discovered that there were many weevils at ground zero and that the signs of damaged trees were everywhere. Moving four miles into the Everglades, we saw that weevils had also reached this location. However, there were fewer weevils and less damage than at ground zero. Going even further in, we found fewer weevils and the trees showed little damage. We concluded that the weevil is progressing across the Everglades, but it is taking time for them to slow down the melaleuca tree growth.

What can you do?

• Visit a nature center and ask about other invasive plants. Some wildflowers are pretty, but if they are planted carelessly, they can overtake an area. Find out what plants are native to your area and which ones are invaders.
   
  
• What are some different ways to control weeds? Compare the benefits and risks of using chemicals, insects, or even other plants to control weeds.
   
  
• For more information on the Florida Everglades and the creatures that call this area home, visit the National Wildlife Federation Web site.
   
  
• Use this life science investigation as a science fair project idea for your elementary or middle school science fair! Then tell us about it!
   
  

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