Blog 8/ Invasive Species

The Cane toad, or Rhinella marina, is native to Central and South America. Adult toads average up to 10cm-15cm.  They usually eat living or dead matter. Female toads lay a single clump that contains thousands of eggs (probably why they are thriving in Australia).
The were first brought in to Australia in 1935.  More than 3000 toads were introduced to sugar cane plantaions in northern Queensland.  The were brought into the plantations to control the French's Cane Beetle and the Greyback Cane Beetle because they were causing alot of damage to the sugar cane crops. While they did control some of the insects, they did not control all of them.  Cane Toads went on to become one of the most highly invasive species in Australia. They have spread quickly all over northern Australia but are mostly in Queensland, New South Wales, and Northern Territory.  Recently, there have been sightings in western AU.
While Cane toads are somewhat controlling insects, they are also posing as a threat to other animals native to AU.  The Cane toad is preyed upon by animals such as crocodiles, goannas, frogs, and many fish.  The problem is that the Cane toad has a deadly defence-mecanism.  When threatened, they have the ability to release a toxin (bufotoxin) from the glands in their eyes and across their back.  Many species of animals have been drastically reduced because of the Cane Toad. 
There have been efforts at controlling the Cane Toad population. One way was to spray pesticides on toad habitats.  This worked signifigantly and reduced the cane toad population but studies by scientists showed that the pesticide was causing cancer in some humans.  That was immediatly put to an end.  Another effort was to catch toads and put them to sleep in a refrigerator for 12 hours and then applying hemorrhoid cram on their backs (to try and stop the poison) but that never caught on.  Most people have just "thrown in the towel".  There has been talk of training predators to not attack the toad.
The multicolored asian lady beetle, or Harmonia axyrdis, is one of many invasive species known to North America.  It came from Asia (obvioulsy) and was introduced to Europe and North America to control the aphid and scale insect population.  It is now a pest that invades homes in october (hibernation).  People have tried to control the lady beetle population by using insecticides, trapping, and even trying to mechanically prevent their entry into buildings.
There should be more concern when it comes to invasive species.  I will admit, when I first heard about invasive species here, I didn't think much of it.  When we learned about the rabbit problem in Australia and what damages they are causing, it made me think alot more about the species here.  There should definaltly be more work done about all of the species that are causing problems in each country.