Question

How are the main classes of arthropods classified according to the presence of a larval stage during their embryonic development?

Answer 1

The three main class of arthropods are: insects ( cockroaches, ants, flies, bees, beetles and butterflies) crustaceans( crabs, lobsters) and arachnids ( scorpions, spiders).

Based on the presence of a larval stage during their embryonic developmet, arthropods are classified as

In crustaceans, some species undergo direct develpoment whereas the other species undergo indirect development.

In insects, some species do not have a larval stage such as ametabolic insects, whereas, others undergo indirect development that begans with an egg stage and ends up at nymph stage( hemimetabolous insects). Some other species of insects undergo indirect development that begans with a larval stage(holometabolous).

*Ametabolism is a type of growth in insects in which there is slight or no metamorphism. There occurs only a gradual increase in size.

* Insects that undergo hemimetabolous metamorphosis emerge from eggs into nymphs. They undergo several nymphal stage before undergoing a final molt into their adult forms.

*Holometabolism is a form of complete metamorphosis. It has four life stages namely an embryo, a larva, a pupa and an adult stage.