Demodex midae, Tokiwa & Ueda & Watanabe & Chou & Ozaki, 2024

Tokiwa, Toshihiro, Ueda, Kengo, Watanabe, Nagi, Chou, Shyun & Ozaki, Kiyokazu, 2024, A new species of Demodex (Acari: Demodecidae) from the skin of golden-handed tamarins, Saguinus midas (Primates: Cebidae), International Journal for Parasitology: Parasites and Wildlife 23, pp. 100920-100920 : 100920-

3.3. Sequence analyses of Demodex midae n sp.

The partial 18S sequence of D. midae n. sp. (527 bp) showed 92.5%–

97.0% identities with Demodex spp. , and the highest homology was found with D. ursi (accession no. KC010482) from the black bear ( Ursus americanus ) and D. musculi (accession no. JF834894) from house mouse ( Mus musculus ) and Demodex sp. from white-tailed deer ( Odocoileus virginianus ) (accession no. KC010483). The identity of Demodex species

L: length, W: width, Asterisk: calculated from the mean value.

parasitic on primates was less than 96.6% for D. folliculorum and 93.7% for D. brevis . No other sequences detected from primates were available. In the ML tree based on 18S sequences, with Myobia ( Trombidiformes : Prostigmata : Myobiidae ) as an outgroup ( Fig. 4A ), Demodex spp. ( Trombidiformes : Cheyletoidea: Demodecidae ) formed a monophyletic group that was well-separated from Cheletomimus and Neochelacheles ( Trombidiformes : Cheyletoidea: Cheyletidae ). Within the Demodex clade, D. folliculorum , D. canis , and D. injai formed a monophyletic clade with relatively high bootstrap values (> 74%). Demodex species derived from the same host ( D. folliculorum and D. brevis in humans, D. canis and D. injai in dogs) were polyphyletic, except for feline D. cati , D. gatoi , and Demodex sp. However, the phylogenetic relationships among these groups and other Demodex species, including D. midae n. sp. were not clear.

The 16S sequence of D. midae n. sp. (292 bp) showed 75.0%–84.5%

homology with Demodex spp. , and the highest homology was found with D. folliculorum (accession no. KF875587). In the midpoint-rooted ML tree based on 16S sequences ( Fig. 4B ), human D. folliculorum and canine D. injai , and human D. brevis and feline D. gatoi showed monophyletic groups, respectively. Although D. midae n. sp. is distinguishable from other Demodex species /isolates, its phylogenetic relationship with these species is unclear.

Figures

Fig. 4. Maximum likelihood phylogenetic trees of Demodex (Trombidiformes: Cheyletoidea: Demodecidae). (A) 18S sequence-based rooted phylogenetic tree with Myobia (Trombidiformes: Prostigmata: Myobiidae) as outgroup and Cheletomimus and Neochelacheles (Trombidiformes: Cheyletoidea: Cheyletidae) as related species of Demodex. (B) 16S sequence-based midpoint-rooting tree. Accession numbers are shown in roman next to the taxa names. Nodes are labeled with bootstrap values greater than 60%. Scale bars represent substitutions per site.