The Colorado potato beetle, Leptinotarsa decemlineata, also known as the Colorado beetle, is a major pest of potato crops. The species was originally found in the Colorado State of the USA and in Mexico, but has spread through the nineteenth and twentieth century over large parts of the Northern hemisphere.

Both adults and larvae feed on foliage and may skeletonize the crop. Particularly during hot summers the species can locally still cause a lot of damage to potato fields in Belgium. I found a field in Afsnee, East Flanders, where most of the potatoes had been harvested and numerous adults were still present. As the adults had not much food left, spectacular numbers of individuals were apparently feeding on the scarce remains of the foliage, but even more intensively on some potatoes which were not harvested.

On this image one can see a bunch of individuals gathered around a potatoe.