Relatively few beetles are directly harmful to humans, although these few species can cause tremendous amounts of damage. These pest beetles have great economic importance with respect to agriculture or the stored products and the materials of which man makes use.
Enemies of agriculture
Since antiquity, humans have had to compete with beetles over various foodstuffs grown or produced in the field. This relationship did not change with the advent of more modern methods of agriculture and product storage. The list of the families of beetles attacking the cultures or the trees is very long and it would be tiresome to quote them all. It should be noted however that certain scarab beetles , metallic wood-borer beetles , long-horned beetles, leaf beetles and snout beetles are among the most significant harmful species.
Eradication of the manioc beetle
The Colorado beetle is a very significant pest of cultivated potato plants, and has even been widely introduced through the mail:
Enemies of the stored food products.
Just like crops in the fields, the food products stored by man, natural or transformed, are attacked and consumed by beetles. Those find there a source of abundant food, constantly renewed; also, there is safety in the containers in which the products are stored. These stored product pest beetles exploit the products of vegetable origin (grains, fibres, wood...) as well that those of animal origin (skins, wools, silk, horn...).
Most significant are the carpet beetles , the seed beetles and the snout beetles, or weevils .