Monday, October 26, 2009

Fall leaves as warning coloration

So, to sort of show whether this theory about whether this

coloration was some sort of warning to insects, the scientists actually put aphids on these

two different types of trees. They put aphids, which are sort of a pest of apple trees, on

trees with leaves that really didn’t change colors, so leaves were mostly green, and they

put the aphids on trees which have a lot of these really bright red leaves. And what they

found was that – come Spring – 60% of the aphids in the green trees survived versus only

29% of those in the red trees. So, even though the scientists didn’t show it specifically, it

seems to argue that maybe there is something poisonous about these red leaves or just

something undesirable about these leaves that’s harmful to the insects, so when the trees

get, you know, bright red, when the leaves get bright red in the Autumn, they’re saying to

insects, “Hey, you’d better stay away.”

http://www.sciencemag.org/cgi/data/324/5925/411b/DC1/1

No comments: