Hello Torben,

Those are Mexican bean beetles. 

See https://entnemdept.ufl.edu/creatures/veg/bean/mexican_bean_beetle.htm

For homeowners, recommended products for controlling insect pests on ornamentals and vegetable garden plants ar cyfluthrin (sold as BioAdvanced Vegetable and Garden Insect Spray, Insecticide), bifenthrin (sold as Ortho Bug B Gon) and carbaryl (sold as Sevin). Neem oil and Spinosad may also be effective. Be kind to our pollinators by spraying in the evening and avoid spraying blossoms. Be sure to read and follow all instructions on the label before using any pesticide.

Best regard