Which insects are known for undergoing gradual metamorphosis?

Insects that undergo gradual metamorphosis, also referred to as hemimetabolism, progress through a series of life stages: egg, nymph, and adult. Unlike complete metamorphosis, where larvae differ significantly from adults, in gradual metamorphosis, the nymphs usually resemble smaller versions of the adults and gradually mature as they molt.

Cave crickets and head lice are both examples of insects that undergo this type of metamorphosis. Cave crickets develop from eggs into nymphs that closely resemble adults, and they continue to molt and grow into their adult form. Similarly, head lice also progress through nymph stages before reaching maturity, maintaining their general body structure throughout the early stages.

In contrast, the other options listed represent insects that undergo complete metamorphosis or don't fit the gradual metamorphosis classification. For instance, butterflies and moths undergo a complete metamorphosis that includes distinct larval (caterpillar) stages that are very different from the adult forms. Bees and wasps, while they have a more complex life cycle, also undergo complete metamorphosis. Lice are similar to head lice but pair them with butterflies does not accurately reflect their metamorphic process. Thus, cave crickets and head lice