What is the difference between a larva and a nymph?

A larva and a nymph represent two distinct developmental stages in the life cycle of insects, differing primarily in their metamorphic pathways. Insects that undergo complete metamorphosis, such as butterflies, beetles, and flies, progress from an egg to a larva, then to a pupal stage, and finally to the adult form. This pupal stage is crucial for significant transformation, allowing for the complex changes needed to develop into the adult insect.

Conversely, insects that undergo incomplete metamorphosis, such as grasshoppers and cockroaches, develop from an egg to a nymph, which resembles a smaller adult but lacks fully developed wings and reproductive structures. This means nymphs do not have a pupal stage during their development; they grow and molt into their adult forms directly.

Therefore, the key differentiating factor is that a larval stage is followed by a pupal stage in complete metamorphosis, while a nymph stage does not involve this pupal intermediary. This distinction is crucial for understanding the life cycles of different insect groups, illustrating how varied their developmental processes can be.