Elytra (or elytrae, more precise technical Entomological word) - plural from Elytron.
It is an upper part of beetle's back (or hardened for-wings), its sort of armor which protects its under-wings (also called hind-wings). At the same time Elytra serves as camouflage: thanks to its various colors and patterns, it helps beetle either to hide, blend into its surrounding or scare away potential predators or enemies.
Unlike most of other insects with 2 functional pairs of wings, beetles (Order Coleoptera) and "true bugs" (Order Hemiptera) have got their upper wings (aka forewings) hardened and can't use them to fly, but only to cover the second pair of wings (aka hind-wings), which are neatly and securely folded under Elytra and are actually used for a flight. Thus, each beetle has its Elytra sort of split or divided into 2 elytrons. Well, in fact there are though some beetles with "unsplit back": their 2 elytrons has fused forever so that it can't be opened, thus under-wings can't unfold - they never flight.
Etymology of word Elytron originates in Greek language, where it means "sheath" (or encasing), or from verb "elyo" = "to wrap up". Indeed common name for Elytra is - wings cases.
For those who're into Entomology, there are few websites and blogs, which provide some more information about meanings and usage of word Elytra. For example, see page for Elytra from website Bug-Guide.
Synonyms for and other forms* of word Elytra:
- wings cases
- shards
- front wings
- forewings
- upper wings
- elytrae (plural)
- elytrum / elytron (singrular)
- elytral, elytrous, elytroid (adjectives)
- elytriform
- Elytrin = Chitin (material of which Elytra are made)
Possible misspellings or often mixed up with words:
- elyctra
- electra
- ultra
* Well, there is actually quite a big list in the "Dictionary of Medical Terms" with root "Ely" - however not exactly related to Entomology, but rather to human Biology or Anatomy. like word Elytroplasty. :)
Coming soon : Pronotum