Top: also, namely 亦 (To see this variation 亦 as red 赤, you can also do.) [red 赤: When earth (clay) 土 is burned 灬, the pottery becomes red 赤], bottom: insect 虫 (The body 口 and the sting ム of an insect.)
Mnemonic
Also, I think: The reddish insects are like: barbarians.
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