Posted by: Footler PJ27 NOV 2008
We know that many plants contain substances that could be of medicinal use. Teams of plant hunters are searching for these medicinally active species before they are wiped out. The problem is, of course, that the plants do not advertise their constituents openly.
It can take many years to find and then analyse any potentially useful material. What we need is a means of identifying such plants easily or at least to help narrow the search before it is too late.
Researchers from the Smithsonian Tropical Research Institute in Panama may have come up with an answer to this problem. They observed brightly coloured beetles and caterpillars, such as the tortoise beetle Charidotis coccinea, and found that they associate with pharmacologically active plants more than they do with inactive ones.
Strange as it may seem, the plants do not simply make these chemicals to suit our needs. They are produced to protect the plant itself from attack by predators. The insects use the same theory but do not generally manufacture the toxins.
Instead they ingest and concentrate the chemicals to make themselves poisonous to their own predators. Their bright colours are a warning to those predators to leave them alone.
Therefore, as the researchers demonstrated, if you can find the plants on which the brightly coloured insects gather and feed you may be on the way to finding a useful medicine. But all of this assumes that the plant and the insect are still there when we come looking for them.
The second item of news suggests we must hurry. It has been reported that another area of pristine Amazonian rainforest about the size of Texas has been earmarked for oil and gas exploration.
The area was divided into 180 blocks and 35 oil companies are competing for contracts to exploit them. Previous experience shows that the surrounding area will also become vulnerable to illegal logging and hunting when roads are built to access the exploration.
Everything from the indigenous population to the largely undisturbed wildlife will go, including those insects and any potentially life-saving plants.
Incidentally the size of Texas is often used as a comparison to other areas of the world. At 268,820 square miles it is the second largest state in the US, after Alaska.