Great enemies of our cultures or our stocks, the beetles however sometimes appeared invaluable auxiliaries in the fight carried out against the enemies of our goods.
Several families provided to some extent exemplary auxiliaries.
Ground beetles , and in first places the calosoma which was one of the first beetles being employed systematically in the fight against another insect. It was imported in the United States, with full success, to fight against the processionary caterpillar.
Other families appear invaluable auxiliaries, as of rove beetles to fight against flies, scarab beetles to ensure the hiding of the dungs, leaf beetles to fight against weeds, or of weevils to fight against thistles.
But the beetles most constantly used and most effective in biological fight meet among the ladybirds . I will give only two examples of them: the introduction in 1888 of Rodolia cardinalis in California to fight against the cochineal Icerya purchasi which extended in the orchards from the country, and Chilocorus bipustulatus in Mauritania to fight against the cochineal of the date palm Parlatoria blanchardi .