I have thousands of black bugs on the rhubarb leaves. The plants are dying. what can I do/
Richland County Illinois
Without pictures, I don't know for sure what insect is attacking your rhubarb plant.
One of the more common pests of rhubarb is the rhubarb curculio. These are 1/2 inch brown or black weevils that have a long snout on their "face". There are pictures, including descriptions of the injury they cause, on this page: http://idl.entomology.cornell.edu/files/2013/11/Rhubarb-Curculio-1hcyg2x.pdf .
This article states for control: The only direct method of control is to hand pick the beetles from the plants during early summer and destroy them. When the beetles first emerge they are easily picked from the vegetation on which they are resting. Their large size aids in finding them and helps make them easy to handle. The removal of all wild plants in which the beetles breed (dock, thistle, and sunflower) growing in or near the planting during July, while the curculio larvae are still in them, will also be helpful.
I checked Purdue's publications, and they say that there are no registered insecticides that will give adequate control.
If this is not what you are seeing, can you please send us a couple of high-resolution photos of the critters?