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Journal #31 – Toads and Cane Beetles

Submitted by robynfarrell on Fri, 04/21/2017 - 11:34

In my evolution class recently we learned about canes beetle and toads. The plant, Sugar cane was planted in a lot of tropical places around the world and it brought about these beetles that would prey on it. It would be such a heavy infestation that you could see swarms of beetles flying around the sugar cane. For a long time, there wasn’t a good solution to get rid of them, but biologists thought of an organism that would help rid them of this beetle. They used a toad as a biological pesticide that would actually consume these bugs. These toads are originally from South Africa, but they have been established in other places like South Florida, Hawaii, and Australia. They proliferated like crazy in Australia. These toads are capable of eating anything that fits in their mouth, and they were also very hard to be predated on since anything that ate it would die, as they had huge poisonous glands next to their head. What made this toad inefficient for the job they needed for was the fact that they were nocturnal and the cane beetles were diurnal, so they were actually really horrible at reducing the number of beetles infesting on sugar cane. They were great at killing other things, so through that their population started to increase rapidly through the coast of Queensland and there was no way stop them. Now throughout hundreds of years there has been a reduction in their size (of toads), toxicity, and their hind legs have been growing longer in proportion to their shrinkage. This is due to the fact that some of the snakes that feed on the toad. Some of the snakes that feed on this toad have also become increasingly larger, so they can assimilate more of the poison without dying, and their heads have gotten smaller so they can eat smaller toads and get smaller amounts of poison.