The order of Beetles (or Coleoptera) belongs to the class of the Insects, itself pertaining to the phylum of the Arthropods (animals with external carapace, segmented body and articulated legs). In addition to the insects, the Arthropods also include crustaceans, Arachnida, scolopendres, etc. The insects are characterized by a body divided into 3 parts: head, thorax and abdomen, by three pairs of legs and two pairs of wings.
Among the insects, the beetles, with more than 350 000 species currently known in the world, form one of the most significant groups. They owe their name (of the Greek koleos, case and pteron, wing) with their former wings corneous (Úlytras) which cover and protect the lower wings membranous and functional.
The beetles are insects with complete metamorphosis. I.e. that, as the butterflies start by being caterpillars, they have larvae very different from the adults, as well in morphology or behavior as in the food. The larvae nothing but do nourish themselves and cannot reproduce. This function deals with the adults. The transformation of the larvae into adults is done by a particular, motionless state: the nymph (equivalent of the chrysalis of the butterflies)
On left: larva of Colorado beetle. On right-hand side: adult.
On left: larva of longhorn beetle. On right-hand side: adult.
Eggs, larva and nympha of scarab beetle.