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Originally Posted by NYCorchidman
Great to know, Camille!
By the way, now that also makes me wonder, if the plants produce more toxic compounds when attacked, why do bugs continue to eat them?
Ok, duh, these are the bugs that are born to eat these plants.
Now I wonder, these plants we talked about, are loaded with toxic compounds so bugs in general do not dare to eat them. So the only bugs that will eat them are the specialists that are not harmed by these toxins. Does increased level of toxin help the plants from these specialist bugs at all?
Or are these plants left vulnerable to these bugs?
I wish all the orchids I grow produced some toxins again mealy bugs and mites.  |
Increasing levels of the toxic compounds does harm them to some extent, but it's just going to slow their growth (so smaller caterpillars) somewhat rather than kill them. It's an evolutionary arms race of sorts. Some plant species don't even bother to ramp up toxin production when attacked by specialists. It's a waste of energy to produce it since it will have limited effect. So the plant's strategy is to relocate its carbon stores in the roots to preserve it's growth potential, and then primarily fight the specialist by attracting natural enemies of the specialist, or wait for the insect to leave and then regrow.
Other plants, like black mustard (which I study) goes into growth overdrive when they detect specialist caterpillars (They can detect the eggs on the leaves just minutes after the butterfly lays them, and react differently if the eggs are from a specialist or a generalist) and accelerates its seed production to grow faster than the caterpillars can eat. Heck some plants ramp up defenses just when they feel an aphid walking across a leaf (because yes, they can sense that too), to get ready for an attack. Plants even "talk" to each other via airborne signals to warn of attacking insects/disease, and the unaffected plants get ready by increasing the defenses.
The toxic compounds don't cause all the generalist insects to drop dead immediately either. Some may nibble on the plant and eventually be deterred by the taste and then leave, others will continue feeding but their growth is so badly affected that they never make it to the adult stage. The plants goal isn't to be completely damage free, but to limit damage enough that their reproduction isn't affected.
I find this field of study absolutely fascinating. If vegetarians even knew a tenth of it, they would reconsider eating plants as well!
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