Consider the following pairs: 1. Mosquito : Egg, Larva, Pupa & Adult 2. Silk moth : Egg, Larva, Pupa and Adult 3. Cockroaches : Egg, Nymph, Pupa and Adult How many of the above pairs are correctly matched?

Complete metamorphosis

• Insects such as the mosquito, the silk moth, the butterfly and the housefly pass through four stages, namely the egg, the larva, the pupa and the adult. This is called complete metamorphosis. Hence, pairs 1 and 2 are correctly matched.
• In the mosquito the larva is called the wriggler and in the silk moth the larva is the caterpillar which spins the cocoon of silk.

Incomplete metamorphosis

• In the cockroach the young one that hatches from the egg is called a nymph, which resembles the adult and grows into an adult by successive moults. There is no pupal stage in the life cycle of the cockroach. Hence, pair 3 is not correctly matched.
• Therefore, only two pairs are correctly matched.