Tyroborus Oudemans

Fan, Qing-Hai & Zhang, Zhi-Qiang, 2006, Revision of Tyroborus Oudemans, 1924 (Acari: Astigmata: Acaridae), Zootaxa 1152, pp. 1-43 : 3-5

publication ID

https://doi.org/ 10.5281/zenodo.172161

DOI

https://doi.org/10.5281/zenodo.5618014

persistent identifier

https://treatment.plazi.org/id/D93A87B1-FFBC-FF87-FEED-FEC7FA95FE38

treatment provided by

Plazi

scientific name

Tyroborus Oudemans
status

 

Genus Tyroborus Oudemans

Tyroborus Oudemans, 1924a: 307 ; 1924b: 325; Hughes, 1976: 68. Tyrolichus (in part): Zakhvatkin, 1941: 98; Robertson, 1946: 197. Tyrophagus (Tyroborus) : Nesbitt, 1945: 176.

Tyrophagus (in part): Hughes, 1961: 46.

Type species: Tyroborus lini Oudemans, 1924 , by original designation.

Diagnosis

FEMALE ( Fig. 16–20 View FIGURE 16 View FIGURE 17 View FIGURE 19 View FIGURE 20 ). Palpal supracoxal seta (elcp) apically bi­ or trifurcate; idiosoma saccate, 300–800 long, whitish to semitransparent. Dorsum with 4 pairs of prodorsal setae (vi, ve, sci and sce) and 12 pairs of hysterosomal setae (c1, c2, c p, c3, d1, d2, e1, e2, f2, h1, h2 and h3), all dorsal setae barbed. External vertical setae obvious, situated at anterior lateral margins of prodorsal shield. Internal scapular setae longer than external scapular setae. Grandjean’s organ finger­like, basally with 3–6 teeth. Supracoxal setae scx broadly widened with dense pectinations. Hysterosomal setae c1 and d2 very short, obviously less than distance to setae in next row; d1 close to c1 and overlapping bases of e1. Coxal plates I not reaching to posterior extremity of prosternal apodeme; coxal plate II reduced to an approximately “L”­shaped sclerite formed by remnant of lateral and anteromedian parts. Genital opening present between coxae III and IV, with 2 pairs of genital papillae covered by genital valves and 1 pair of genital setae (g). Genital folds present. Anal opening posteriorad of genital opening, with 6 pairs of setae (ad3, ps3, ad2, ad1, ps2 and ps1). Spermathecal duct narrowing from copulatory opening for a distance, forming a neck and then gradually widening to base of spermathecal sac. Legs light brown. Tarsi I–II stout, about twice as long as basal width. Dorsoapical seta e on tarsi I–II conical. Proral setae on tarsi I–IV present or absent, if present, conical, more slender than unguinal setae. Chaetotaxy of legs (I–IV): coxae 1, 0, 2, 1; trochanters 1, 1, 1, 0; femora 1, 1, 0, 1; genua 2 + 2, 2 + 1, 1 + 1, 0; tibiae 2 + 1, 2 + 1, 1 + 1, 1 + 1; tarsi 7 + 1 dorsoapical spine + 3–5 ventroapical spines + 3 + 1, 6 + 1 dorsoapical spine + 3–5 ventroapical spines + 1, 4 + 1 dorsoapical spine + 3–5 ventroapical spines, 4 + 1 dorsoapical spine + 3–5 ventroapical spines.

MALE ( Fig. 21–25 View FIGURE 21 View FIGURE 22 View FIGURE 23 View FIGURE 24 View FIGURE 25 ). Similar to adult female except: genital opening situated between coxae IV; aedeagus present; with a pair of anal suckers; without adanal setae; tarsus IV having 2 suckers. Complement of setae on legs as in adult female except tarsi IV with 3 + 1 dorsoapical spine + 3–5 ventroapical spines.

Remarks

After a comparative study of Tyroborus species, including T. lini , T. miripes (Athias­ Henriot) comb. nov. and T. ueckermanni sp. nov., and 17 species of Tyrophagus ( Fan & Zhang 2006) we found two new distinct characters, palpal supracoxal seta (elcp) ( Figs. 3 View FIGURE 3 C, 8B) and coxal plate II ( Fig. 4 View FIGURE 4 A), to separate Tyroborus from Tyrophagus . Four other previously known characters are also useful ( Table 1 View TABLE 1 ). The proral setae p and q on the tarsi used by Hughes (1976) and Fain (1986) are of little value at the generic level because their size varies from species to species.

Species of Tyroborus are similar to Tyrolichus in dorsoapical seta e on tarsi being conical, tarsi I–II being stout and about twice as long as basal width, supracoxal seta scx having numerous projections, but can be distinguished from the latter by having apically bi­ or trifurcated elcp ( Figs. 3 View FIGURE 3 C, 8B) and “L” shaped coxal plate II ( Fig. 4 View FIGURE 4 A), both c1 and d2 being very small ( Fig. 1 View FIGURE 1 A), and at least one pair of setae surrounding anus in female being short ( Fig. 24 View FIGURE 24 B).

Tyroborus houstoni Fain, 1986 is closer to Tyrolichus casei Oudemans, 1910 rather than to species of Tyroborus . Although sci in the larva are shorter than sce, as in Tyroborus lini , this species is not considered a species of Tyroborus because its setae c1, d1, d2, ad1–3 and ps1–3 are relatively long, coxal plate II is not reduced to an “L”­shaped sclerite. Therefore, it is not considered a species of Tyroborus here. Further study is needed to clarify its taxonomic placement.

1. Proral setae on tarsi I–IV prominent ( Figs. 8 View FIGURE 8 F, 10A–D); ' longer or as long as " on genu I ( Fig. 10 View FIGURE 10 A)........................................................................................................... 2

­ Proral setae on tarsi I–IV absent or vestigial ( Figs. 4 View FIGURE 4 C, E, 5A–D); ' obviously shorter than " on genu I ( Fig. 5 View FIGURE 5 A); CHINA, CUBA, EGYPT, ENGLAND, INDIA, MEXICO, NETHERLANDS, NEW ZEALAND, SPAIN, TURKEY.......... T. lini Oudemans, 1924

2. Supracoxal seta scx with 32–34 pectinations in male ( Fig. 8 View FIGURE 8 D) and 38–46 in female ( Fig. 13 View FIGURE 13 C); 1 on tarsus I slightly widened at apex in male ( Figs. 9 View FIGURE 9 C); ALGERIA.......

.................................................................................... T. miripes ( Athias­Henriot, 1961) ­ Supracoxal seta scx with 16–22 pectinations in male (Fig. 18C) and 16–24 in female ( Fig.23 View FIGURE 23 D); 1 on tarsus I obviously widened at apex in male( Fig.19 View FIGURE 19 C); SOUTH AFRICA................................................................................................... T. ueckermanni sp. nov.

TABLE 1. Characters for separating Tyroborus and Tyrophagus.

  Tyroborus Tyrophagus
elcp Apically bi­ or trifurcate (Figs. 3C, 8B) Not branched
Coxal plate II Reduced to an approximately “L”­shaped sclerite formed by remnant lateral and anteromedian parts (Fig. 4A) Broad or concave in posterior margin but not “L”­shaped
e on tarsi Thick, conical (Fig. 4C) Thin, setiform
Tarsi I–II Stout, about twice as long as basal width (Fig. 5A, B) Slender, more than 3x of basal width
scx With more projections (Figs. 3E, 13 C) With fewer projections
sci in larva Shorter than sce Longer than sce
Key to adults of Tyroborus Oudemans  

Kingdom

Animalia

Phylum

Arthropoda

Class

Arachnida

Order

Astigmata

Family

Acaridae

Loc

Tyroborus Oudemans

Fan, Qing-Hai & Zhang, Zhi-Qiang 2006
2006
Loc

Tyrophagus

Hughes 1961: 46
1961
Loc

Tyroborus

Hughes 1976: 68
Robertson 1946: 197
Nesbitt 1945: 176
Zakhvatkin 1941: 98
Oudemans 1924: 307
1924
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