蜀 was founded by Liu Bei (刘备) in 221 AD, with Zhuge Liang (诸葛亮) as chancellor - the state made famous by 《三国演义》. Today it survives as the one-character abbreviation for Sichuan: car plates read 川 or 蜀.
虫 (the indexing radical) is the literal worm - silkworm specifically. The whole graph is a giant silkworm, which over centuries became the name for the silkworm-rich Sichuan region and then the Three Kingdoms state Shu Han based there.
罒 sits on top - historically not a net here but a horizontally-laid 目 (eye), depicting the bulging eyes of a silkworm. The original picture of 蜀 is a wide-eyed worm rearing up; that curled-worm imagery survives in the curve below.
勹 wraps around the lower body - depicting the worm's coiled, hunched torso. It frames 虫 inside, completing the picture of a curled silkworm with its head reared and its body bent into the strike-pose.
