noun
beetle
BEE-tul/ˈbiːtl/
An insect with hard front wings covering its flight wings.
The beetle has six legs and hard wing covers.

Etymology
Old English bitela apparently meant a “little biter” or “biting insect.” The name thus points to the insect's biting mouthparts, rather than its hard wing covers.
In context
the toughened wing covers so when a beetle flies its wings are oh they open up and they've been hidden by these hard casing covers that are over the beetle's back