| Jeffrey Pettingill explains that biocontrol insects were originally released 25-30 years ago, but they do not completely control Musk Thistle by themselves. If we look lower on the plant we will notice some new buds, new parts of the plants and new flowers. The insects won't eat these lower levels because the seeds produced will be next years food supply for them. Therefore, the insects will not eradicate or get rid of the entire weed.
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