Beetles are an order of insects called coleoptera. The origin of the word is Greek and means sheathed wing, which can be explained by the fact that the majority of beetles have two pairs of wings: the upper pair called elytra which are sheath-like and protect the pair underneath called alae as well as the rear part of the beetle’s body. The elytra are hardened and have to be raised in order to move the alae for flying. Beetles can have specialised organs such as defensive glands producing chemicals for predator deterring and glands for pheromone production. Only two species have hearing organs; they detect ultrasonic frequencies to protect the beetles from bats.
When it comes to reproduction, beetles may behave intricately when mating. Depending on the species of beetle, different chemicals are used as pheromones to attract a mate. Some beetles do not use pheromones, they mate with the help of bioluminescence instead. This phenomenon of producing biosynthesized light is attributed to fireflies which produce light with their abdomen. In mating rituals of beetles, conflicts may arise between males and males or between males and females. Sometimes male beetles defend their patch of territory against an opponent. For that reason, some male beetles have horns on their heads or thorax. Before mating, male beetles of some species stroke the female with their antennae.
The life cycle of a beetle starts with the egg, developing into larva and pupa. Eggs are laid on a substrate that provides food for the larva while hatching. Some beetle parents are more caring than others, thus not only lay eggs but also provide their young with food, housing and protection. The principal feeding stage of a beetle is the larva, voraciously feeding once emerged from the egg. The larvae go through several stages: Mostly they increase only in size however more drastic changes may occur. Finally, the larvae pupate and develop into sexually mature adult beetles called imago.
Most coleoptera are phytophagous and can therefore be considered pests for humans and their crops. However, some species are beneficial in that they control the populations of other pests. In 80% of the world’s nations beetles are used as food.