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Insects and Plants
Plants against Insects
- Mechanical and chemical defence by plants.
Change colour
- Chemical - Toxic, bad taste - e.g. herbs
- Herbs are short life plants, adapted the chemical defence mechanism.
- The toxic has to be rare and keep on changing to avoid being adapted by insects.
- Physical - hairy, spiny, hard skin,
Plants depend on Insects
Flowers
Why some leaves are not green in colour?
Green is the colour of photosynthesis, so most plants are green in colour. However, some plants, especially some young shots are red in colour.
There could be more than one reasons that young leaves are not green in colour. The mismatched colour to expose the camouflaged insects must be one of the important reason. Most leaf eating insects like to feed on the young leaves, and most of them camouflaged in green leaf colour. The mismatched colour makes the insect camouflage not so effective and exposes the insect to its predators.
As the pictures above, if the katydid was not sitting (because it is feeding too) on the young red leaves, it was harder to be seen.
