Clearly related is the verbal root *ply ‘to delouse’ widely attested throughout Semitic.
Cf. Tna. ˁafäl ‘insects or fleas which live in grass’ (TED 1949). One wonders whether it could be directly compared to Akk. uplu (< *ˁupl-)?
PWS
*ply - to delouse
(SED II No. 175; Kogan 2011: 213)
fāliyat- - kind of insect similar to the scarab marked with black and white spots which usually accompanies or precedes scorpions or vipers
(BK 2 635, Lane 2446, LA XV 164)
Usually in combination fāliyatu l-ˀafāˁī ‘f. of the snakes’
Amharic
fälfäl - swarm of termites which leave the mound at the onset of the rainy season
(AED 272)
According to Kane, derived from a verbal root meaing ‘to hatch (locusts)’