Tyroborus lini Oudemans, 1924

Fan, Qing-Hai & Zhang, Zhi-Qiang, 2006, Revision of Tyroborus Oudemans, 1924 (Acari: Astigmata: Acaridae), Zootaxa 1152, pp. 1-43 : 5-12

Tyroborus lini Oudemans, 1924

( Figs. 1–5 , Plate 1)

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

Tyrophagus lini: Hughes, 1961: 46 .

Material examined

Type: 1/ 1 male, THE NETHERLANDS: “in oud lnzaad, Arnhem, Oct 1923, Oudemans” ( RMNH Acari P 6875).

Diagnosis

MALE. Supracoxal seta scx broadly widened at bases of pectinations, bearing 21–24 pectinations; d1 about 3.5× length of c1 and 4.6× length of d2; d2 about 0.8× length of c1; aedeagus tapering from base to tip, apical end small, straight, lateral arms supporting aedeagus turning outwards; ratio I ': " = 0.7, (a+b): c = 4.1; solenidia I 1 and II moderately slender, cylindrical, not widened at apex.

Description

MALE ( Fig. 1–5 , Plate 1)

Idiosoma. 331 long, 211 wide. Chelicera 88 long, cha conical, 6 long, subcapitular setae m 36, palpal supracoxal seta elcp 16–18 long, apically bifurcate, dorsal palptibial seta 18, lateral palptibial seta 25, dorsal palptarsal seta 16, palptarsal solenidion 4.

Dorsum. Prodorsal shield nearly pentagonal in shape and obviously punctate, 70 long, 88 wide between ve­ve. Eyespots not observed. Grandjean’s organ finger­like, 10 long, its basal lobe with 3 obvious spiniform teeth; supracoxal seta scx broadly widened at bases of pectinations, 31 long, bearing 21–24 pectinations. All dorsal idiosomal setae sparsely pectinated. Ratios: vi: ve = 2.3, sci: sce = 1.4, sci­sci: sci­sce = 1.5. Lengths of setae: vi 71, ve 31, sci 132, sce 94; distances: vi­vi 8, vi­ve 40, sci­sci 36, sci­sce 24. Hysterosomal setae d1 about 3.5× length of c1 and 4.6× length of d2; d2 about 0.8× length of c1; lengths of setae: c1 24, c2 136, c p 111, c3 24, d1 close to c1, 83 long, d2 18, e1 202, e2 137, f2 243, h1 252, h2 197, h3 157; distances: c1­c1 78, c1­d1 30, d1­d1 35, d2­gla 37, d1­ e 1 73, e1­ e 1 72.

Venter. Setae 1a 40; 3a 20; 3b 39; g 20, 4a 38. Aedeagus tapering from base to tip, 30 long, with one major curve and a small reverse apical end, internal diameter uniform throughout its apical part; lateral arms supporting aedeagus turning outwards. Anal slit 50. Anal suckers about 30 in diameter; anal discs 4 in diameter, distance between right and left discs 33. Pseudanal setae ps1 about 81 long, ps2 34 long, ps3 15; ps1­ps1 34, ps2­ps2 48.

Leg I. 156 long; femur I 43, vF simple, 36 long; genu I 34, ' 22, " 30, I ': " = 0.7, cG 27, mG 33; tibia I 26, 93, gT 24, hT 18; length of tarsus I (excluding claw) about 1.7× width, 42 long, 25 wide, 1 moderately slender, cylindrical, not widened at apex, 15 long, 3.5, 2 7, 3 23, distance between aa and 1 about 8, aa 17 long, ba 16, wa 16, ra 25, la 17, d 27, e stout, 6, f 14, s stout, 7, u and v stout, 7, p and q absent, claw 14.

PLATE 1. Tyroborus lini Oudemans (male). A, prodorsal shield; B, supracoxal seta; C, aedeagus; D, solenidia on tarsus I; E, solenidion on tarsus II; F, tarsus IV.

Leg II. 153 long; femur II 45, vF 44; genu II 31, 20, cG 27, mG 30; tibia II 23, 81, gT 21, hT 21; length of tarsus II (excluding claw) about 1.9× width, 38 long, 20 wide, not widened at apex, 16 long, ba 16, wa 16, ra 15, la 25, d 31, e 7, f 11, s stout, 7, u and v stout, 7, p and q absent, claw 14.

Leg III. 150 long; femur III 33; genu III 27, 13, nG 33; tibia III 25, 69, kT 28; length of tarsus III (excluding claw) about 2.3× width, tarsus III 39 long, 17 wide, w 22, r 17, d 24, e 6, f 15, s stout, 7, u and v stout, 7, p and q absent, claw 13.

Leg IV. 163 long; femur 35, wF 27; genu IV 31; tibia IV 27, 68, kT 26; length of tarsus IV (excluding claw) about 2.7× width, tarsus IV 46 long, 17 wide, w and r situated at level between suckers, w 29 long, r 20 long, distance between basal rim of tarsus IV and proximal sucker d 13, between d and e 21, between e and f 8, ratio (a+b): c = 4.1 ( Fig. 4 E), f 25, s stout, 7, u and v stout, 7, p and q absent, claw 12.

FEMALE AND LARVA

According to Hughes (1976), idiosoma in female is 331 long and 211 wide; setae sci in larva are much shorter than sce. Claparède organs are cylindrical.

Habitats and distribution

Tyroborus lini was first described from old linseeds by Oudemans (1924a) and has since been found infesting stored products or indoor materials from countries in Palaearctic, Nearctic, Afrotropical, Oriental, and Australian Regions ( Table 2 ). It takes 14 to 17 days to complete its life cycle at 23o C, 87 R.H. on wheat germ ( Hughes 1976). No deutonymphal stage (hypopus) is known.

Distribution Host Reference

China Chinese medicine Li, 1999

Figures

FIGURE 1. Tyroborus lini Oudemans (male). Dorsal view of idiosoma.

FIGURE 2. Tyroborus lini Oudemans (male). Ventral view of idiosoma.

FIGURE 3. Tyroborus lini Oudemans (male). A, ventral view of chelicera; B, ventral view of apical part of chelicera; C, ventral view of subcapitulum; D, Grandjean's organ; E, F, supracoxal seta; G, prodorsal shield; H, lateral view of aedeagus.

FIGURE 4. Tyroborus lini Oudemans (male). A, coxae I – IV; B, ventral view of aedeagus and anus; C, tarsus I; D, solenidion on tarsus II; E, tarsus IV.

FIGURE 5. Tyroborus lini Oudemans (male). A, leg I; B, leg II; C, leg III; D, leg IV.