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Author Topic: Examples of biological methods of controlling invasive species?  (Read 7758 times)

Offline Talia

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Can you give me some examples of biological methods of controlling invasive species?


 

Offline CliffordK

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One biological method that has proven effective is the importation of the  cinnabar moth to control tansy ragwort (ragweed)

Of course, one issue with biological controls is that the controlling species often doesn't wipe out the invasive species, but rather knocks down the numbers significantly.  It has actually been years since I've seen the moth caterpillars here, so I fear there will be somewhat of a resurgence of the weed, but it has been proven easy enough to control without pesticides.

You should also read about biological controls that didn't go as planned.  For example the cane toad, imported to Australia to control the cane beetle.

Several of the more problematic invasive species were intentionally imported.  For example European (and American) Beach grasses.  Hmm, biological control of it?  It is pretty indestructible, but dune buggies can make a dent in it. :-\  Personally I think the state should continually rotate the dune buggy access areas to help control these invasive species.
 

Offline Talia

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thank you!
 

Offline CliffordK

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There have also been other types of biological controls.

The Dung Beetle has been used to compete with opportunistic species such as maggots.

There is current research on using bacteria phages (viruses) to combat bacterial infections.

Here is a great article about the use of sterile insects to combat both endemic and invasive insect species.

Likely the approach will be used to combat Malaria.

As far as the difference between the cinnabar moth and the cane toad above.  I believe the cinnabar moth is extremely species dependent with it's food source.  Both good and bad.  Once it kills off all the tansy, the moths die back significantly, but it is relatively easy to re-introduce them as needed.  Here is a good description of the moth, which apparently is TOXIC, but didn't seem to cause any major issues with native wildlife.

The cane toad, above, was far less specific, and thus can spread beyond its intended targets.  It also is toxic to wildlife, which causes a problem with native wildlife that do attempt to eat them (not having historical exposure to the toads).  Of course, there is more concern today than was the case in the past about our impact on native species and environments.

The beach grasses were imported to control sand, which they do very well.  But, times have changed, and so the goals of a century ago aren't necessarily the goals of today.  The rapidly disappearing beaches are wonderful tourist attractions.  I've never seen the beaches without the grass, but the invasive grass is damaging to native species such as the snowy plover
 

Offline Don_1

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The psyllid Aphalara itadori is under trial as a solution to the problem of Japanese Knotweed in the UK.

Look here: http://news.bbc.co.uk/1/hi/8555378.stm
 

Offline Talia

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thank you Don!
 

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