The Colorado potato beetle is a highly destructive pest that eats the foliage of the potato plant thereby destroying potato crops.
Colorado Potato Beetle or just potato beetle (Leptinotarsa decemlineata).
This specimen was photographed in Békéscsaba, Hungary.
The potato beetle originated from Colorado but it has spread to other places, unfortunately it has also reached Europe a while ago, so it can destroy crops on both sides of the Atlantic Ocean.
Potato beetles breed very fast and both the larvae and the adult beetles feast on potato leaves until there isn’t any left.
The usual defense is to poison them with pesticides, but they can become resistant to some types of poison. There are also some biological options such as using predatory insects that prey on potato beetle larvae or using a pathogenic fungus to kill potato beetles. It is not clear to me how specific these are and whether they rather feast on the local bug population. Also there is concern if they control Colorado potato beetles sufficiently.
There are other options, for example rotating crops, since potato beetles have a limited choice of host plants that can sustain them.
I remember that in Hungary when people used to plant potatoes in their back yard gardens often a simple solution was to just pick the potato beetles off the plants by hand and kill them. But almost nobody grows potatoes in their back yards any more and this method does not work well for large potato fields.
Further Readings:
Colorado potato beetle website.
Colorado potato beetle – Leptinotarsa decemlineata (Say).
Colorado potato beetles in home gardens.