butterfly
蝴 centers on the butterfly, a specific insect. The meaning is narrow and concrete, referring to the winged insect itself.
蝴 combines 虫 (insect) with 胡, which likely contributes the sound コ. The character was created to represent a butterfly, a type of insect.
The left side 虫 means insect, and the right side 胡 looks like an old-fashioned butterfly net or a decorative wing pattern. Picture a butterfly caught in an insect net.
For コ, imagine a butterfly landing on a small 子 (こ, child) who is holding very still. The child's reading こ cues the butterfly's reading コ.
—