are one of the largest orders of insects, comprising the sawflies, wasps, bees and ants. Over 150,000 species are recognized, with many more remaining to be described. The name refers to the wings of the insects, and is derived from the Ancient Greek ὑμήν (hymen
): membrane and πτερόν (pteron
): wing. The hind wings are connected to the fore wings by a series of hooks called hamuli.