In his study of Proto-Kam-Sui (PKS) initials, Ferlus (1996) tentatively reconstructed initial *ˀl- based on a set of four comparisons with high-register tones, including ‘wasp’ and ‘boar’:
|wasp||la:u A1||lu A1||du A1||-lu A1|
|boar||lai B1||-la:i B1||-da:i B1||-la:i B1|
The probable Austronesian prototypes are *waNu ‘honeybee’ and *waNiS ‘boar’s tusk, boar’ in Blust’s PAN reconstructions. Recall that *N was a lateral, probably simply [l], in PAN, until it shifted to *n after Proto-Southern-Austronesian, in PMP. As a daughter of PSA (here), PKD retained *N as [l]. Evolution of *waNiS to tone B in PKS is unexplained, but has a parallel in the reflex of *gumiS ‘moustache, beard’ in Kra: Buyang mui 11 (B) ‘body hair, feather’.
In PSA, initial *w- became *ʔw- with phonetic glottal stop: ʔwalu, ʔwaliS. This ʔw- underwent fortition to *p- in Proto-Hlai (Ostapirat *pəlu A, Norquest *p-lu: A). In PKS, *ʔwal- simplified to ʔwl- and ultimately to Ferlus’s *ʔl-.
The Kam-Sui word for ‘blood’, Ferlus *pʰr-, Thurgood *phla:t 7, can now more confidently be related to PAN *huRaC ‘artery, blood vessel, blood vein’ (Blust) with fortition of initial *XuR- to *pʰr- via [ɸr-] vel sim., parallel and similar to the fortition of *ʔul- to *pl- in Hlai.
Ferlus, Michel. 1996. Remarques sur le consonantisme du proto kam-sui. Cahiers de Linguistique Asie Orientale 25: 235-278.
Norquest, Peter. 2015. A Phonological Reconstruction of Proto-Hlai. Brill.
Ostapirat, W. 2004. Proto-Hlai sound system and lexicons. in: Ying-ching Lin, Fang-min Hsu, Chun-chih Lee, Jackson T.S. Sun, Hsiu-fang Yang and Dah-an Ho (eds), Studies in Sino-Tibetan languages, papers in honor of Professor Hwang-cherng Gong on his seventieth birthday, 121-175. Nankang: Institute of Linguistics, Academia Sinica.