| abstract | Considerable dispute exists with regard to the classification of hair follicle mites, belonging to the family Demodicidae in the last twenty to thirty years, due to indistinct morphological characteristics.
In the present investigation, we carried out further detailed studies on the classification of the family Demodicidae and made a comparative study on the species Demodex folliculorum, the human hair follicle mite.
The taxonomic characteristics of the family Demodicidae are chiefly: 1. number, position and shape of palpal claws (setae), 2. shape and distance between two supracoxal spines, 3. shape of pharyngeal bulb, 4. shape and position of aedeagus, 5. position and with or without lid of genital orifice, 6. shape of posterior portion of opisthosoma, 7. presence or absence and shape of proctodaeum.
A table of comparative measurements in micron of length and width of gnathosoma, podosoma, opisthosoma, and total length of and among three human species and subspecies of hair follicle mites, was made for differentiation. A list of 15 species and subspecies of hair follicle mites was given, including their species names, Chinese names and hosts. We found that the common human hair follicle mite in China is different from those in other countries. We, therefore, propose to erect a new subspecies.
Demodex folliculorum sinensis, subsp. nov.
The differential characteristics of the new and the nominate subspecies of Demodex folli-culorum are given in the following table for comparison.
f.folliculorum the nominate subspecies f. sinensis the new subspecies
♀ 294µ > ♂ 279.7µ ♂ 302.07µ > ♀ 296.99µ
Posterior opening of pharngeal bulb narrow Posterior opening of pharyngeal bulb broad
Pharyngeal bulb narrow horse-shoe-shaped Pharyngeal bulb broad horse-shoe-shaped
Aedeagus short, 24.2µ in length Aedeagus long, 32µ in length
♂ genital orifice situated in between 2nd pair ♂ genital orifice situated near center and
of dorsal podosomal setae in between 1st and 2nd pairs of dorsal
podosomal setae
Holotype ♀ allotype ♂ and paratypes 20♀♀ 20♂♂ were collected off man in Shanghai; deposited in the Department of Parasitology, Shanghai First Medical College, Shanghai. |