what metamorphosis had two kinds of larval instars and a pupal instar and winged adult
The correct answer and explanation is:
The correct answer is complete metamorphosis.
In insects with complete metamorphosis, such as butterflies, beetles, and flies, the life cycle consists of four distinct stages: egg, larva, pupa, and adult. The larval stage can have two types of instars (immature stages) before transitioning into a pupal stage.
- Egg: The insect starts as an egg laid by the adult.
- Larva: After hatching, the insect enters the larval stage. The first instar is the initial phase after hatching, followed by one or more additional instars where the larva grows and molts. In some species, there are two larval instars before the insect moves to the next stage.
- Pupa: The insect then enters the pupal stage, which is a resting or transformative phase. During pupation, the insect undergoes significant reorganization, including the formation of wings, legs, and other adult features.
- Adult: The adult emerges from the pupa, often winged, and is fully formed with the reproductive organs necessary to continue the species.
In this process, the two larval instars are part of the initial stages of growth where the insect is primarily focused on feeding and increasing in size. Once it reaches the required size, the larva enters the pupal stage, which is a form of dormancy or transition to the adult form. The adult is typically winged, indicating its ability to move and reproduce.
This process is different from incomplete metamorphosis, which involves only three stages: egg, nymph (which molts into larger versions of the adult form), and adult, without the pupal stage. In insects undergoing complete metamorphosis, the pupal stage allows for a complete transformation, making it a unique and efficient survival strategy in the insect world.