Aponychus taishanicus Wang, 1981

Pan, Xiao-Juan, Jin, Dao-Chao & Yi, Tian-Ci, 2023, Redescription of three species of Aponychus from China with ontogenetic development and morphological variations of A. corpuzae (Acariformes: Tetranychidae), Zootaxa 5324 (1), pp. 185-226 : 217-224

Aponychus taishanicus Wang, 1981

( Figs 35–44 )

Aponychus taishanicus Wang 1981: 222 .

Material examined

Paratypes: five females and two males, collected on leaves of Grewia biloba (Malvaceae) , from Taishan, Shandong Province, China, by Hui-Fu Wang, on September 16, 1974. All specimens are deposited at Institute of Zoology, Chinese Academy of Sciences, Beijing, China

Redescription

Female (n = 5)

Dorsum ( Figs 35–36 ). Idiosoma oval, 239–286 long excluding gnathosoma, 285–342 including gnathosoma, 212–282 wide; idiosomal dorsum humped, integument with fine lines. All dorsal setae stout, covered with short barbs, inserted on strong tubercles full of punctuations. Prodorsal setae three pairs (v 2, sc 1, sc 2), setae v 2 and sc 1 elongated, stout, set on strong tubercles, sc 1 longer than v 2, twice as long as setae sc 2; setae sc 2 stout, slightly dilated near tip; length of setae: v 2 62–77, sc 1 102–130, sc 2 28–66.

Hysterosomal dorsum integument with fine lines and transverse bulky wrinkles between setae c and d rows; dorsocentral setae (c 1, d 1, e 1) similar to sc 1, elongated with sharp ends and subequal, longer than distances between bases of setae and setae in next row; c 2, d 2 and f 1 similar to dorsocentral setae; c 3, f 2 and h 1 similar in shape of sc 2, rodlike, slightly dilated near tip, f 2 much shorter than others; length of dorsal setae: c 1 100–115, c 2 103–114, c 3 42–50, d 1 89–107, d 2 109–124, e 1 95–100, e 2 98–104, f 1 98–112, f 2 21–32, h 1 45–64; distance between dorsal setae: v 2 – v 2 52–62, sc 1 – sc 1 101–109, c 1 –c 1 36–58, d 1 –d 1 62–89, e 1 – e 1 51–76, f 1 –f 1 69–109, h 1 –h 1 34–52.

Venter ( Fig. 37 ). Striae mostly transverse. Genital flap striae transverse, genital and anal region with oblique transverse anterior-laterally, longitudinal medially and transverse undulating striae posteriorly. All ventral setae thin and smooth. Setae 1a, 3a and 4a shorter than distance between their bases respectively. Coxal setae count 2-2-1-1, one pair of pseudanal setae (ps 1), two pairs of smooth genital setae (g 1-2), two pairs of para-anal setae (h). Length of setae: 1a 27–31, 3a 45–56, 4a 47–56, ag 42–48, g 1 44–68, g 2 48–55, ps 1 13–17, h 2 19–30, h 3 31–41. Distances between setal bases: 1a–1a 43–50, 3a–3a 62–65, 4a–4a 83–95, ag–ag 22–33 g 1 – g 1 26–36, g 2 – g 2 43–56, ps 1 – ps 1 20–29, h 2 – h 2 28–35, h 3 – h 3 36–60.

2-3

Gnathosoma ( Fig. 38 ). Stylophore with a shallow cleft anteriorly forming two projections.Ventral infracapitular setae m smooth, 28–31 in length. Palp setation and notation as shown in Figure 38A . Palptarsus: terminal eupathidium (suζ) with blunt tipped, 4–7 long, two lateral eupathidia (ul′ζ and ul″ζ), ul′ζ 5.6–8.4 and ul″ζ 4.2–7.6 long, one solenidion (ω) 4.3–4.9 long; three short, smooth, tactile setae (a, b, c). Peritreme ending in small expansion ( Fig. 38B ).

Legs ( Fig. 39 ). Empodial claws absent. One set of duplex setae on tarsus I, solenidion ω″ 14–17, single tc on tarsus I; tibia I with one solenidion φ 8–12 long; one pair duplex setae on tarsi II, solenidion ω″ 10–15 long; tarsi III and IV with one solenidion ω″ 4–7, ω″ 5–7 respectively. Segmental length of legs: trochanter I 31–41, femur I 107– 116, genu I 50–75, tibia I 55–79, tarsus I 67–85; trochanter II 31–41, femur II 93–99, genu II 46–61, tibia II 59–65, tarsus II 68–78; trochanter III 27–32, femur III 77–91, genu III 36–46, tibia III 67–75, tarsus III 77–84; trochanter IV 26–34, femur IV 96–111, genu IV 38–46, tibia IV 77–85, tarsus IV 84–95; legs chaetotaxy I–IV (eupathidia and solenidia in parenthesis): trochanters 1-1-1-1; femora 7 or 6-4-3 or 2-2 or 1; genua 3-3-1-1; tibiae 5(0; 1)-4-3-3; tarsi 7(3; 1)-7(3; 1)-7(0; 1)-7(0; 1); chaetotaxy of legs shows in Fig 39 .

Venter. Similar to female, striae mostly transverse, all ventral setae thin and smooth. Coxal setae count 2-2-1-1; length of setae: 1a 28–30, 3a 12–15, 4a 19–21; distance between intercoxal and coxae setae: 1a–1a 28–32, 3a–3a 20–22, 4a–4a 19–22.

Gnathosoma. Stylophore similar to female, having two shallow distal lobes; ventral infracapitular setae m smooth; palptarsus: terminal eupathidium (suζ) elongate, with blunt tipped, 3.7–4.2 in length; two lateral eupathidia (ul′ζ and ul″ζ) subequal in length, 5.4–6.5; one solenidion (ω), 3.5–3.9; three tactile setae (a, b, c), short, smooth, slender; peritreme ending in small expansion.

Aedeagus ( Figs 42–43 ). Aedeagus gradually narrowing and bent distally with blunt tipped.

Legs ( Fig. 44 ). Tarsal empodia absent; one pair of duplex setae and two to four solenidia on tarsus I, four solenidia ω′ 16–18, ω″ 13–15, ω′ 1 15–17, vω 13–15; tibia I with four solenidia φ 13–17, φ′ 12–14, φ″ 13–17, φ″ 1 13–16 long; tarsus II with one pair of duplex setae and two solenidia ω″ 14–17, ω′ 15–18, ω″ 1 12–14 long; tarsi III and IV with one solenidion ω″ 10–12, ω″ 10–13 respectively; segmental length of legs: trochanter I 33–42, femur I 119–133, genu I 51–60, tibia I 85–96, tarsus I 79–86; trochanter II 28–38, femur II 100–115, genu II 51–54, tibia II 73–74, tarsus II 68–81; trochanter III 23–30, femur III 89–107, genu III 48–65, tibia III 67–102, tarsus III 95–126; trochanter IV 28–34, femur IV 93–121, genu IV 41–48, tibia IV 92–101, tarsus IV 86–94; legs chaetotaxy I–IV (eupathidia and solenidia in parenthesis): trochanters 1-1-1-1; femora 9-7-4-2; genua 3-3-2-2; tibiae 6(0; 4)-6 or 5(0; 2)-4-4; tarsi 7(3; 3 or 4 or 5) -7(3; 3)-7(0; 1)-7(0; 1); chaetotaxy of legs as show in Figure 44 .

Remarks

We examined paratypes of A. taishanicus including five females and two males here. The chaetotaxy of legs shows the intraspecific polymorphism in this species: the setal count of females shows that one in five with six tactile setae on right and left sides of femur I, two in five with seven tactile setae on both sides of femur I, two in five with seven tactile setae on left and six on right of femur I; four in five with three tactile setae on both right and left sides of femur III, one in five with three tactile setae on left and two on right of femur III; four in five with two tactile setae on both right and left sides of femur IV, one in five with one tactile seta on left and two on right of femur IV; female femur I with seven tactile setae, femur III with three tactile setae, femur IV with two tactile setae (both regarded as normal setal counts).

The setal count of males shows that one in two males with three solenidia on left and four solenidia on right of tarsus I; one in two males with four solenidia on left and five solenidia on right of tarsus I; one in two males with five tactile setae and two solenidia on left and six tactile setae and two solenidia on right of tibia II; one in two males with five tactile setae and two solenidia on both left and right sides of tibia II. Male tarsus I with four solenidia, tibia II with five tactile setae and two solenidia are regarded as normal setal counts.

The setal count of male and female described here is different from Wang’s (1981) description: female femur IV with two tactile setae is regarded as normal setal counts here, whereas femora III–IV both have three tactile setae as described by Wang (1981); we find tarsus II with 11 setae (the same number as tarsus I) different from 10 setae on tarsus II described by Wang (1981). Wang (1981) described that male tarsus I has 13 setae in total, and tibia II has 11 setae in total (without giving setal count of solenidia on male tarsus I–II); our setal count of males show that tarsus I has 14 setae including seven tactile setae, three eupathidia and four solenidia, and tarsus II has 13 setae including seven tactile setae, three eupathidia and three solenidia.

Figures

FIGURE 35. Aponychus taishanicus. Female: dorsum.

FIGURE 36. Aponychus taishanicus. Photograph. Female: dorsal view of idiosoma.

FIGURE 37 Aponychus taishanicus. Female, venter.

FIGURE 38. Aponychus taishanicus. Photographs. Female, A, palp; B, stylophore and peritreme.

FIGURE 39. Aponychus taishanicus. Female, A–D, left side legs I–IV, respectively.

FIGURE 40. Aponychus taishanicus. Male: dorsum.

FIGURE 41. Aponychus taishanicus. Photograph. Male: dorsal view of idiosoma.

FIGURE 42. Aponychus taishanicus. Male, A–B, aedeagus.

FIGURE 43. Aponychus taishanicus. Photographs. Male, aedeagus.

FIGURE 44. Aponychus taishanicus. Male, A–D, left side legs I–IV, respectively.