Right
虫 supplies the sound - the traditional
燭 had
蜀 (shǔ, silkworm) here as the phonetic; the simplification kept just the
虫 part, which still echoes the original zhú-family reading. Same phonetic logic appears in
浊 (zhuó) muddy,
触 (chù) to touch, all once sharing this Shu/Zhu sound family.
