An insect that has both nymphs and adults is the European spruce gall adelgid.

An insect that has both nymphs and adults is the European spruce gall adelgid.

• A. European spruce gall adelgid
• B. Colorado potato beetle
• C. Aphid
• D. Spider mite

Answer: (A)

The life cycles of many insects can be described by whether they undergo incomplete or complete metamorphosis. Incomplete metamorphosis means immature stages called nymphs resemble smaller versions of the adult and go through several molts before reaching maturity. The European spruce gall adelgid is a true bug (an adelgid) that exhibits this pattern, with nymphal stages present alongside adults, making it a clear example of an insect that has both nymphs and adults. The Colorado potato beetle, in contrast, goes through complete metamorphosis—egg, larva, pupa, and adult—so there isn’t a nymph stage. Spider mites aren’t insects at all, they’re arachnids, so they don’t fit the criterion of an insect with nymphs and adults. Aphids do have nymphs and adults as part of their life cycle, but within the given options the European spruce gall adelgid is the specific insect group highlighted for demonstrating both stages on conifers, making it the best-supported choice.

The life cycles of many insects can be described by whether they undergo incomplete or complete metamorphosis. Incomplete metamorphosis means immature stages called nymphs resemble smaller versions of the adult and go through several molts before reaching maturity. The European spruce gall adelgid is a true bug (an adelgid) that exhibits this pattern, with nymphal stages present alongside adults, making it a clear example of an insect that has both nymphs and adults.

The Colorado potato beetle, in contrast, goes through complete metamorphosis—egg, larva, pupa, and adult—so there isn’t a nymph stage. Spider mites aren’t insects at all, they’re arachnids, so they don’t fit the criterion of an insect with nymphs and adults. Aphids do have nymphs and adults as part of their life cycle, but within the given options the European spruce gall adelgid is the specific insect group highlighted for demonstrating both stages on conifers, making it the best-supported choice.