Once upon a time, in coastal SE China, a flea ran into a louse. Hello, said he, I see you lay eggs, you must be a female. I am looking for a mate, will you marry me? All right, said the louse. And since then, speakers of Guangzhou, Chaozhou, Jieyang (and other dialects, I am sure), have been calling fleas as 蝨 /sɐt 7/, /sak 7/, /sak 7/ (etymologically ‘louse’) respectively; and lice, /sɐt 7 na 3/, /sak 7 bo 3/, /sak 7 bo 3/; that is, etymologically ‘louse’+female suffix.
Cite this post as: Laurent Sagart, "A Christmas story for lovers (of insect names)," in Sino-Tibetan-Austronesian, 28/12/2017, http://stan.hypotheses.org/158.