Fetching details from the dictionary...
imago; adult (insect)
成虫は交尾を終えると間もなく死ぬ。
Adult insects die shortly after mating.
幼虫から成虫になるまで約二週間かかる。
It takes about two weeks to go from larva to adult insect.
さなぎから羽化した成虫は体がまだ柔らかいことが多い。
Adult insects that have emerged from a chrysalis are often still soft-bodied.