How are the main classes of arthropods classified according to the presence of larval stage in their embryonic development?
In crustaceans there are species with direct and others with indirect development. In insects there are species with no larval stage (ametabolic insects), others undergoing indirect development beginning with an egg stage followed by a nymph stage (hemimetabolic insects) and others with indirect development starting with the larval stage (holometabolic insects).
The transformation of a larva into an adult individual is known as metamorphosis. Hemimetabolic insects endure incomplete metamorphosis while holometabolic insects undergo complete metamorphosis.