Review on the Genus Stylophoronychus (Acari: Tetranychidae), with Description of a New Species ^†

Simple Summary

The spider mite family Tetranychidae includes 85 genera and more than 1300 species worldwide, and is the group of phytophagous mites that has the greatest impact on the agricultural economy. Stylophoronychus is a small genus of six species that belongs to the tribe Aponychini which was reinstated as a valid taxon containing three genera (Aponychus, Paraponychus and Stylophoronychus). Here, a new species Stylophoronychus wangae Pan, Jin & Yi sp. nov. from Majiang Country, Guizhou Province, China (the Oriental realm) is described based on the deutonymph and adults. Two species, S. guangzhouensis (Ma and Yuan, 1980) and S. lalli (Prasad, 1975) are considered junior synonyms of S. vannus (Rimando, 1968). The taxonomy of the genus Stylophoronychus is reviewed and the studies on its ontogenetic development are discussed.

Abstract

Only two species of the genus Stylophoronychus, S. baghensis (Prasad, 1975) and S. guangzhouensis (Ma and Yuan, 1980), have been recorded in China. Herein we describe a new species Stylophoronychus wangae Pan, Jin & Yi sp. nov. based on characteristics of the deutonymphs and adults. The synonym of S. guangzhouensis (Ma and Yuan, 1980) and S. lalli (Prasad, 1975) with S. vannus (Rimando, 1968) is proposed. A redescription of S. vannus (Rimando, 1968) based on the adults of both sexes, deutonymphs and a protonymph is given. The ontogenetic changes of leg chaetotaxy in two species are given and discussed. The updated key to the species of Stylophoronychus of the world is provided.

1. Introduction

The genus Stylophoronychus belongs to the tribe Aponychini of the subfamily Tetranychinae and contains six species (S. baghensis, S. guangzhouensis, S. insularis, S. lalli, S. nakaoi and S. vannus) [1,2,3,4]. Most of these species are distributed in the Oriental realm, primarily found on Bambusa spp., with the exception of S. insularis which has been reported only from Araliaceae sp. in the Ethiopian realm [1,3,5]. Stylophoronychus was originally erected as the subgenus of Aponychus by Prasad to accommodate S. baghensis based on two strong lobes of the stylophore [1,6]. Later, the subgenus was elevated by Meyer [7] to the generic status due to the key character of nine pairs of dorsal setae on the hysterosoma, and all the species of Stylophoronychus were reclassified based on this character [1,7]. For more detailed changes in the classification of the genus refer to Zhang et al. [1].

Stylophoronychus guangzhouensis is endemic to China and resembles S. vannus and S. lalli [1,2,5,8,9]. Hernandes and Feres [2] compared three species of Stylophoronychus and one species of Aponychus. Zhang et al. [1] conducted a detailed comparative analysis and provided a key to the species of Stylophoronychus. They considered A. bambusae a junior synonym of S. vannus while S. guangzhouensis (not examined), S. lalli and S. vannus were separate and valid species. There is a slight difference in the shape of setae h₁ being more palmate in S. vannus in comparison to the relatively slimmer shape observed in S. lalli and S. guangzhouensis. After performing a comparative analysis of the morphological characters of five species (S. baghensis, S. guangzhouensis, S. lalli, S. vannus and S. wangae Pan, Jin & Yi sp. nov.) of the genus (not S. insularis and S. nakaoi), we consider S. guangzhouensis and S. lalli to be junior synonyms of S. vannus. We examined Ma’s collection of S. guangzhouensis (originally deposited at the Shanghai Museum of Natural History, Shanghai, China and Shanghai Agricultural College, Shanghai, China) which included 13 females, six males, and five deutonymphs from Jinghong City, Yunnan Province. We also examined new collections of S. guangzhouensis collected by Tian-Ci Yi from leaves of Chimonobambusa quadrangularis (Fenzi) Makino in Guangzhou City, Guangdong Province which included one protonymph, one deutonymph and six females. In addition, specimens of S. vannus from six collections that include one paratype female, two females, three males and one paratype female of S. lalli, and two paratype females of S. baghensis borrowed from the USNM, were compared and studied.

The ontogenetic development of leg chaetotaxy in spider mites having one pair of duplex setae on tarsus I, which is rare, is poorly known. To reach a better understanding of this genus, a protonymph, deutonymphs and adults of S. vannus and a deutonymph and adults of S. wangae sp. nov. were collected and reared to examine the ontogenetic development and provide a description of the immature stages of these species.

2. Materials and Methods

The mite specimens studied were examined using a Leica DM 5000B microscope with differential interference contrast. Line drawings were prepared with the aid of a drawing tube attached to the microscope. Photographs were taken under oil immersion using a camera (Nikon DS-Ri 2) attached to the microscope (Nikon Ni E). Measurements were obtained using software (Nikon NIS Elements AR 4.50) and are provided in micrometers (µm). Length of the idiosoma was measured from the center of the setal base of v₂ to h₁, while width was measured from the center of the setal base of c₁ to c_3. The measurements are presented for the holotype followed by the range of paratypes in parentheses. Morphological terminology follows that of Lindquist [10].

3. Results

3.1. Taxonomic Discussion in S. guangzhouensis, S. lalli, S. vannus

These three species were compared based on the following characteristics:

(1) Idiosoma. The body shapes of the adult females for all three species have the idiosoma nearly oblong, slightly longer than wide, and margins on both sides approximately parallel (Figure 1).

(2) Dorsal setae. For the three species shown in Figure 1 and

Table 1. Measurements of idiosoma and dorsal setae of three species of Stylophoronychus.

Species (Female)	S. guangzhouensis n = 19	S. lalii n = 1	S. vannus n = 3
Idiosoma
Length (v2–h1)	299–338	296	311–324
Width (c3–c3)	269–297	264	272–281
Dorsal setae
v2	31–38	35	34–39
sc1	32–37	40	30–38
sc2	50–56	55	44–55
c1	62–72	62	59–78
c1–c1	48–53	39	38–45
c1–d1	58–62	58	59–76
c2	22–29	26	24–29
c3	50–65	55	56–61
d1	61–68	74	60–76
d1–d1	85–100	96	95–100
d1–e1	76–85	78	79–91
d2	41–51	38	34–44
e1	54–72	68	60–66
e1–e1	59–90	83	74–80
e1–f2	63–82	68	59–86
e2	43–52	53	43–48
f2	41–46	50	39–47
h1	37–46	48	39–42

, the dorsocentral setae are long, linear, inserted on tubercles and pubescent. They are characterized such that their length, with the exception of the first row, is approximately equal or shorter than distances between their bases. The key provided by Zhang et al. [1] uses the relative length of e₁ subequal and less than the distance between their bases to distinguish among the three species, but this character is unreliable. According to Hernandes and Feres [2], the shape of setae h₁ is the only character that can distinguish these three species reliably but only when a large series of specimens is examined. However, after examining 19 female specimens of S. guangzhouensis, we found the shape of setae h₁ is variable, ranging between spatulate, fan-like or palmate. Figure 2 and Figure 3 show that S. guangzhouensis shares the shapes of h₁ setae with the other two species. This variation of the shape of h₁ is most likely intraspecific polymorphism and cannot be used as a character to distinguish the three species.

(3) Patterns of hysterosomal median protuberance. S. guangzhouensis, S. lalli and S. vannus have a protuberance on the hysterosomal median that arched upward, shaped like the outline of butterfly wings, densely covered with irregular patterns of circles or the fusion of many circles (Figure 4).

(4) Patterns of integument on medial prodorsum. S. guangzhouensis, S. lalli and S. vannus have a nearly square bulge on the prodorsal median area with a conspicuous pattern of highly wrinkled ornamentation that resembles a brain cortex (described by Hernandes and Feres) (Figure 5).

(5) Stylophore. There are similar apicodorsal granulations on the two strong lobes of the stylophore with a median convex area in S. guangzhouensis, S. lalli and S. vannus (Figure 6).

(6) Leg chaetotaxy. Females of the three species have the same legs chaetotaxy I–IV (eupathidia and solenidia in parentheses): trochanters 1-1-1-1; femora 6-5-3-1; genua 1-1-1-1; tibiae 3(1)-1-1-1; tarsi 7(3)(2)-7(3)(1)-6-6(0)(1). However, the leg chaetotaxy shows an intraspecific polymorphism for the three species. Three females of S. vannus were examined, and one paratype female shows 6-6(1) on tarsus III–IV, while the other two females show 7-7(1). Leg chaetotaxy of tarsus III–IV in S. guangzhouensis is more variable.

Based on the above common typical characteristics analysis, S. guangzhouensis, S. lalli and S. vannus are considered to be synonymous, the latter species having priority. The variations on tarsus III–IV of Stylophoronychus vannus as shown in

Table 2. The number of mutations on tarsus III–IV of Stylophoronychus vannus (solenidia in parentheses).

Type	Left Legs	Right Legs	Proportion
1	6-6(1)	6-6(1)	10/23
2	6-6(1)	7-6(1)	3/23
3	6-6(1)	6(1)-6(1)	1/23
4	6-7	6(1)-6(1)	1/23
5	6-7(1)	6-6(1)	1/23
6	7-6(1)	7-6(1)	1/23
7	7-7(1)	7-6(1)	1/23
8	7-7(1)	7-7(1)	4/23
9	7-6(1)	Leg III broken	1/23

.

3.2. Redescription of S. vannus

Family Tetranychidae Donnadieu

Subfamily Tetranychinae Berlese

Tribe Aponychini Rimando & Corpuz-Raros

Genus Stylophoronychus Prasad, 1975

Aponychus vannus Rimando, 1968

Aponychus (Stylophoronychus) vannus (Rimando); Prasad, 1975

Stylophoronychus vannus (Rimando); Meyer, 1987

Redescription

Figure 7, Figure 8, Figure 9, Figure 10, Figure 11, Figure 12, Figure 13, Figure 14, Figure 15, Figure 16, Figure 17, Figure 18 and Figure 19

Adult female (n = 23)

Dorsum (Figure 7 and Figure 8). Idiosoma vermilion, 296–338 long, 264–297 wide, nearly oblong, slightly longer than wide and lateral margins approximately parallel. Dorsal setae white. Hysterosoma with two distinct protuberances anterior, one small and bears seta c₁, posterior, one large constricted laterally (between d₁ and e₁), and bears setae d₁ and e₁.

Prodorsum with three pairs of palmate to spatulate setae, covered with short longitudinally aligned spinules, v₂ 31–39, sc₁ 30–40 and sc₂ 44–56. Distances between setal bases: v₂–v₂ 79–87, sc₁–sc₁ 111–127, sc₂–sc₂ 224–239. Prodorsum with a pattern resulting in highly wrinkled ornamentation on those transverse ridges.

Hysterosoma with 11 pairs of setae (c_1–3, d_1–2, e_1–2, f₂, h_1–3), f₁ absent and f₂ marginally positioned. Setae c₁, c₃, d₁ and e₁ elongate palmate to long linear, c₂ much shorter than other dorsal setae, about as long as one third of seta c₁; e₂, f₂ and h₁ palmate or spatulate. Setae h_2–3 of differing morphology, similar to other ventral setae and inserted posteroventrally. Seta c₁ slightly longer than the distance to setae d₁. Seta d₁ shorter than the distance to seta e₁. Length of setae: c₁ 58–78, c₂ 24–29, c₃ 50–65, d₁ 60–76, d₂ 34–51, e₁ 59–72, e₂ 43–48, f₂ 40–47, h₁ 37–42, h₂ 18–27, h₃ 15–25. Distances between setal bases: c₁–c₁ 39–53, c₂–c₂ 120–133, c₃–c₃ 272–280, d₁–d₁ 85–100, d₂–d₂ 233–248, e₁–e₁ 76–90, e₂–e₂ 154–171, f₂–f₂ 104–130, h₁–h₁ 38–64, c₁–d₁ 59–76, d₁–e₁ 79–91, e₁–f₂ 59–86, f₂–h₁ 25–28. Hysterosoma dorsally with a pattern may be resulting in highly wrinkled ornamentation that somewhat round convex on protuberances, oblique wide ridges laterally, and opisthosoma dorsally with longitudinal ridges.

Venter (Figure 9 and Figure 10A). Striae mostly transverse, pregenital striae transverse and broken. Genital flap with transverse striae. All ventral setae thin and smooth. Setae 1a as long as distance between their bases; setae 3a and 4a shorter than distance between their bases. Coxal setae count 2-1-1-1, one pair of pseudanal setae (ps₁), two pairs of smooth genital setae (g_1–2). Length of setae: 1a 19–22, 3a 18–23, 4a 14–21, ag 13–17, g₁ 25–36, g₂ 25–35, ps₁ 11–15. Distances between setal bases: 1a–1a 19–28, 3a–3a 37–46, 4a–4a 80–92, ag–ag 20–25, g₁–g₁ 25–32, g₂–g₂ 48–63, ps₁–ps₁ 16–44.

Gnathosoma (Figure 10B,C). Stylophore with well-developed bilobed horn-like anterior projections. Integument of base of stylophore with longitudinal striae, projections with granulate pattern (Figure 10B). Ventral infracapitular setae m smooth, 18–19 in length. Palp setation and notation as shown in Figure 10C. Dorsal surface of palp base with a pair of inconspicuous supracoxal setae (e). Palptarsus: terminal eupathidium (suζ) club-like with blunt tip end, 4.4–5.9 long, two lateral eupathidia, ul′ζ 4.4–5.8 and ul″ζ 4.3–5.3 long, one solenidion (ω) 2.9–4 long; three short, smooth, tactile setae (a, b, c).

Legs (Figure 11A–D). Empodial claws absent. One pair of duplex setae on tarsus I, solenidion ω′ 8–9, one additional ventral solenidion (vω) at the same transverse level with u setae, 10–14 long, tectal seta (tc′) unpaired, thicker than other tactile setae on tarsus I; tibia I with one solenidion φ 10–12 long; tarsus II without duplex setae, solenidion ω″ 10–13 long, tectal seta (tc′) unpaired, thicker than other tactile setae; tarsus III without solenidion, tectal setae paired; tarsus IV with one proximal solenidion ω′ 6–7 long, tectal setae paired. Number of tactile setae on leg (I–IV) segments: trochanters 1-1-1-1, femora 6-5-3-1, genua 1-1-1-1, tibiae 3-1-1-1, tarsus 7-7-6 (or 7) -6 (or 7). Number of eupathidia on tarsus I–IV: 3-3-0-0. Legs I–IV setation and notation as shown in Figure 11A–D. Length of leg segments: femur I 99–110, genu I 41–46, tibia I 39–47, tarsus I 67–74; femur II 81–90, genu II 38–45, tibia II 31–38, tarsus II 62–71; femur III 67–78, genu III 33–36, tibia III 37–41, tarsus III 75–78; femur IV 96–102, genu IV 33–44, tibia IV 44–45, tarsus IV 79–85.

Number of tactile setae on Tarsus III–IV varies among specimens, and differs between right and left legs in the same specimen (Table 2). Among 23 adult females, 12 (one from Thailand, one from India, six from Yunnan Province, China and four from Guangdong Province, China) with six tactile setae (u′, u″, ft′, ft″, pv′, pv″) on both right and left tarsus III; six (two from Thailand, four from Yunnan Province, China) with seven tactile setae (u′, u″, ft′, ft″, pv′, pv″, v′₁) on both right and left tarsus III; three (two from Yunnan Province, China and one from Guangdong Province, China) with seven tactile setae on right tarsus III and six tactile setae on left; one (from Guangdong Province China)with six tactile setae (u′, u″, ft′, ft″, pv′, pv″) and one solenidion (ω′) on right tarsus III and six tactile setae on left; one (from Yunnan Province, China) with seven tactile setae on left tarsus III and unknown the right side due to the broken tarsus III. Among 23 adult females, 15 (one from Thailand, one from India, eight from Yunnan Province, China and five from Guangdong Province, China) with six tactile setae (u′, u″, ft′, ft″, pv′, pv″) and one solenidion (ω′) on both right and left tarsus IV; four (two from Thailand, two from Yunnan Province, China) with seven tactile setae (u′, u″, ft′, ft″, pv′, pv″, v′₁) and one solenidion (ω′) on both right and left tarsus IV; two (from Yunnan Province, China) with seven tactile setae and one solenidion on left tarsus IV and six tactile setae and one solenidion on right; one (from Guangdong Province, China) with seven tactile setae on left tarsus IV and six tactile setae and one solenidion on right; one (from Yunnan Province, China) with six tactile setae and one solenidion on left tarsus IV and unknown the right side due to the broken tarsus IV. The variations in the setal count of tarsus III and IV are here considered intraspecific in nature, and attributed to the geographical position of the samples and different host plant species. In order to express the ontogenetic development of leg chaetotaxy conveniently, tarsus III with six tactile setae and tarsus IV with six tactile setae and one solenidion are regarded as normal setal count.

Setal counts (solenidion in parentheses following tactile setae) on legs I–IV are: femora 6-5-3-1, genua 1-1-1-1, tibiae 3(1)-1-1-1, tarsus 7(2)-7(1)-6(0)-6(1). There is a significant amount of setal suppression on the legs in this species, with a total of 15 setae being added to the legs in the adult female stage of this species: pair l₁ on femur I, pair v₁ on tarsus I, pair l₁ on femur II, pair v₁ on tarsus II, v′ on trochanter III, v′ and l′₁ on femur III, l′ on genua III, v′ on trochanter IV, l″ on genua IV and ω′ on tarsus IV. According to the normal ontogenetic setal additions for the family [10], seven of thirteen additional setae are delayed additions: v′₁ on tarsus I suppressed on protonymph stage, v″₁ on tarusus I, v′₁ on tarsus II, v′ on trochanter III and IV, l on genua III and IV are suppressed on deutonymph stage.

Male (n = 9)

Dorsum (Figure 12). Idiosoma gradual narrowing caudally, 184–209 long, 123–147 wide, with length much longer than width. Dorsum without a protuberance.

Prodorsum with three pairs of palmate setae, covered with short longitudinally aligned spinules, v₂ 19–21, sc₁ 32–37 and sc₂ 19–21. Distances between setal bases: v₂–v₂ 50–54, sc₁–sc₁ 74–76, sc₂–sc₂ 133–145. Integument with irregular fine granulate.

Hysterosoma with 11 pairs of setae (c_1–3, d_1–2, e_1–2, f₂, h_1–3), similar in shape to prodorsal setae, except with setae h_2–3 of differing morphology, similar to other ventral setae and inserted posterodorsally. Seta c₂ slightly shorter than other dorsal setae. Dorsal central setae (c₁, d₁, e₁) much shorter than the distance to setae in the next setal row. Length of setae: c₁ 17–19, c₂ 13–15, c₃ 24–26, d₁ 16–18, d₂ 19–20, e₁ 13–16, e₂ 20–22, f₂ 21–26, h₁ 17–23, h₂ 13–23, h₃ 13–16. Distances between setal bases: c₁–c₁ 21–25, d₁–d₁ 37–40, e₁–e₁ 25–25, f₂–f₂ 57–59, h₁–h₁ 28–31. Hysterosoma dorsally with irregular fine granulate, except for band of transverse striae between paired c₁ and d₁.

Venter (Figure 13). Striae mostly transverse. All ventral setae thin and smooth. Coxal setae count 2-1-1-1. Length of setae: 1a 20–21, 3a 16–21, 4a 13–15, ag 14–17, g₁ 6–8, g₂ 5–9, ps₁ 5–6. Distances between setal bases: 1a–1a 22–24, 3a–3a 31–38, 4a–4a 34–38, ag–ag 7–8.

Gnathosoma (Figure 10B–D). Stylophore with short bilobed horn-like anterior projections as shown in Figure 10B. Ornamentation of integument similar to that of female. Ventral infracapitular setae m smooth, 11–17 in length. Palp setation and notation as shown in Figure 10D. Palptarsus: terminal eupathidium (suζ) club-like with sharp tip end, 2.8–3 long, two lateral eupathidia, ul′ζ 5–6 and ul″ζ 5–7 long, one solenidion (ω) 3–5 long; three short, smooth, tactile setae (a, b, c).

Legs (Figure 14A–D). Empodial claws absent. One pair of duplex setae on tarsus I, solenidion ω′ 12–14, ω″₁ 8–11 long, one additional ventral solenidion (vω) at the same level with u setae, 13–16 long, tectal setae (tc′) unpaired, thicker than other tactile setae on tarsus I; tibia I with four solenidion, φ 12–13, φ′ 8–9, φ″ 6–8, φ″₁ 8–10 long; tarsus II without duplex setae, solenidion ω″ 11–14 long, tectal setae (tc′) unpaired, thicker than other tactile setae; tibia II with two solenidion, φ′ 8–9, φ″ 8–9 long, tarsus III with one solenidion ω′ 7–9, tc paired; tarsus IV with one proximal solenidion ω′ 7–9 long, tc paired. Number of tactile setae on leg (I–IV) segments: trochanters 1-1-1-1, femora 6-5-3-1, genua 2-2-1-1, tibiae 3-1-1-1, tarsus 7-7-7-7. Number of eupathidia on tarsus I–V: 3-3-0-0. Legs I–IV setation and notation as shown in Figure 14A–D. Length of leg segments: femur I 78–86, genu I 40–42, tibia I 46–47, tarsus I 67–68; femur II 74–76, genu II 39–42, tibia II 39–39, tarsus II 64–64; femur III 78–79, genu III 33–37, tibia III 32–40, tarsus III 69–73; femur IV 81–85, genu IV 35–38, tibia IV 44–44, tarsus IV 75–80.

The number of tactile setae on tarsus III and tarsus IV varies among specimens, and differs between right and left legs in the same specimen. Among nine adult males, seven (three from Thailand, four from Yunnan Province, China) with seven tactile setae (u′, u″, ft′, ft″, pv′, pv″, v′₁) and one solenidion (ω′) on both right and left tarsus III; one (from Yunnan Province, China) with eight tactile setae (u′, u″, ft′, ft″, pv′, pv″, v′₁, v″₁) and one solenidion (ω′) on both right and left tarsus III; one (from Yunnan Province, China) with eight tactile setae and one solenidion on left and seven tactile and one solenidion on right. Among nine adult males, four (from Yunnan Province, China) with six tactile setae (u′, u″, ft′, ft″, pv′, pv″) and one solenidion (ω′) on both right and left tarsus IV; three (two from Thailand, one from Yunnan Province, China) with 7 tactile setae (u′, u″, ft′, ft″, pv′, pv″, v′₁) and one solenidion (ω′) on both right and left tarsus IV; and two (one from Thailand, one from Yunnan Province, China) with eight tactile (u′, u″, ft′, ft″, pv′, pv″, v′₁, v″₁) and one solenidion (ω′) on right Tarsus IV and seven tactile setae and one solenidion on left. The variations in the setal count of tarsus III and IV are here considered intraspecific in nature, and attributed to the geographical position of the samples and different host plant species. In order to express the ontogenetic development of leg chaetotaxy conveniently, tarsus III–IV with seven tactile setae and one solenidion are regarded as normal setal counts.

The male has a slightly different chaetotactic formula to the female. Setal counts on legs I–IV: femur 6-5-3-1, genua 2-2-1-1, tibia 3(4)-1(2)-1-1, tarsus 7(3)-7(1)-7(1)-7(1). The male adds four more tactile setae to legs than the dose for the female, accurately, l’ on genua III and IV, v″₁ on tarsus III and IV. The male also adds more solenidia to the legs than does the female: φ’, φ″, φ″₁ on tibia I, ω″₁ on tarsus I, φ’, φ″ on tibia II and ω′ on tarsus III.

A total of 26 setae were added to the legs in the adult male stage of this species, and 11 additional setae are delayed additions: v′ on Genua I and II suppressed in larva stage, v′₁ on tarsus I suppressed on protonymph stage, and v″₁, ω″₁ on tarusus I, v′₁ on tarsus II, v′ on trochanter III and IV, l′ on genua III and IV, and ω′ on tarsus III are suppressed on deutonymph stage. Tarsus III in male of S. vannus does not express standard adult seta v′₁, replaced by v″₁.

Aedeagus (Figure 13A,B). Aedeagus dorsally curved, gradually narrowing and bent distally to form a somewhat right angle.

Deutonymph (n = 6)

Dorsum (Figure 15). Idiosoma oval without protuberance on hysterosoma. 190–268 long, 168–230 wide.

Prodorsum with three pairs of club-like setae, covered with short longitudinally aligned spinules, v₂ 25–26, sc₁ 30–31 and sc₂ 26–30. Distances between setal bases: v₂–v₂ 45–46, sc₁–sc₁ 72–78 and sc₂–sc₂ 108–173. Integument with irregular fine granulate medially and longitudinal stiae laterally.

Hysterosoma with 11 pairs of setae (c_1–3, d_1–2, e_1–2, f₂, h_1–3), similar in shape to prodorsal setae, except with setae h_2–3 of differing morphology, similar to other ventral setae and inserted posteroventrally. Seta c₂ much shorter than other dorsal setae. Dorsal central setae (c₁, d₁, e₁) shorter than the distance to setae in the next setal row. Length of setae: c₁ 27–30, c₂ 13–15, c₃ 24–26, d₁ 62–68, d₂ 25–25, e₁ 24–27, e₂ 26–29, f₂ 25–26, h₁ 22–25, h₂ 12–13, h₃ 14–15. Distances between setal bases: c₁–c₁ 26–32, d₁–d₁ 40–42, e₁–e₁ 26–34, f₂–f₂ 51–61, h₁–h₁ 33–34. Hysterosoma dorsally with irregular fine granulate, except for band of transverse striae between paired c₁ and d₁, and oblique broken striae on opisthosoma.

Venter. Striae mostly transverse. All ventral setae thin and smooth. Setae 1a as long as distance between their bases; setae 3a and 4a shorter than distance between their bases. Coxal setae count 2-1-1-1, one pair of pseudanal setae (ps₁) and one pair of smooth genital setae (g₁). Length of setae: 1a 12–15, 3a 11–16, 4a 9–10, ag 9–11, g₁ 9–10, ps₁ 7–7. Distances between setal bases: 1a–1a 26–31, 3a–3a 40–47, 4a–4a 54–58, ag–ag 10–10.

Gnathosoma (Figure 10F and Figure 15). Stylophore with slightly or well-developed bilobed horn-like anterior projections. Ornamentation of integument similar to that of female. Ventral infracapitular setae m smooth, 13–16 in length. Length of setae on palptarsus: suζ 3–3.4, ul′ζ 4.8–6, ul″ζ 5.5–7, ω 2–2.8.

Legs (Figure 16A–D). Empodial claws absent. One pair of duplex setae on tarsus I, sometimes setal bases of ft′ and ω′ separated, solenidion ω′ 5–6, one additional ventral solenidion (vω) at the same level with u setae, 7–10 long, tectal seta (tc′) unpaired, thicker than other tactile setae on tarsus I; tibia I with one solenidion 5–8 long; tarsus II without duplex setae, solenidion ω″ 8–10 long, tectal seta (tc′) unpaired, thicker than other tactile setae; and tarsus III and tarsus IV without solenidion. Number of tactile setae on leg (I–IV) segments: trochanters 1-1-1-0, femora 4-3-1-1, genua 1-1-0-0, tibiae 3-1-1-1, tarsus 5-5-6-6. Number of eupathidia on tarsus I–V: 3-3-0-0. Legs I–IV setation and notation as shown in Figure 16A–D. Length of leg segments: femur I 46–53, genu I 18–22, tibia I 21–26, tarsus I 36–39; femur II 40–44, genu II 18–19, tibia II 18–20, tarsus II 32–37; femur III 34–40, genu III 15–19, tibia III 17–22, tarsus III 35–38; femur IV 34–39, genu IV 15–18, tibia IV 18–22, tarsus IV 30–41.

Four setae are added to the legs of the deutonymph of this species during ontogeny: l′ is added to femur I. v′ on trochanter I–III, respectively. A total of 50 setae are suppressed on legs I–IV in the deutonymphal stage of this species: two on femur I, four on genua I, four on tibia I, eight on tarsus I, four on genua II, four on tibia II, three on tarsus II, one on femur III, three on genua III, four on tibia III, three on tarsus III, one on femur IV, three on genua IV, four on tibia IV, and two on tarsus IV.

Protonymph (n = 1)

Dorsum (Figure 17 and Figure 18). Idiosoma oval without protuberance on hysterosoma, 198 long, 148 wide.

Prodorsum with three pairs of club-like setae, covered with short longitudinally aligned spinules, v₂ 50, sc₁ 44 and sc₂ 32. Distances between setal bases: v₂–v₂ 50, sc₁–sc₁ 82, sc₂–sc₂ 148. Integument with irregular fine granulate medially and broken longitudinal stiae laterally.

Hysterosoma with 11 pairs of setae (c_1–3, d_1–2, e_1–2, f₂, h_1–3), similar in shape to prodorsal setae, except with setae h_2–3 is of differing morphology, similar to other ventral setae and inserted posteroventrally. Seta c₂ much shorter than other dorsal setae. Dorsal central setae (c₁, d₁, e₁) slightly longer than the distance to setae in the next setal row. Length of setae: c₁ 43, c₂ 22, c₃ 34, d₁ 42, d₂ 44, e₁ 37, e₂ 38, f₂ 30, h₁ 29, h₂ 12, h₃ 10. Distances between setal bases: c₁–c₁ 29, d₁–d₁ 48, e₁–e₁ 35, f₂–f₂ 63, h₁–h₁ 36. Hysterosoma dorsally with irregular fine granulate, except for band of transverse striae between paired c₁ and d₁, narrow band of transverse striae between d₁ and e₁, and oblique broken striae on opisthosoma.

Venter. Striae mostly transverse. All ventral setae thin and smooth. Setae 1a and 3a shorter distance between their bases. Coxal setae count 2-1-1-0, one pair of pseudanal setae (ps₁). Length of setae: 1a 13, 3a 33, ag 11, ps₁ 7. Distances between setal bases: 1a–1a 24, 3a–3a 33, ag–ag 11.

Gnathosoma (Figure 17). Stylophore with slightly bilobed horn-like anterior projections. Ornamentation of integument similar to that of female and deutonymph. Ventral infracapitular setae m smooth, 12 in length. Length of setae on palptarsus: suζ 3.6, ul′ζ 5.6, ul″ζ 6.7, ω 2.

Legs (Figure 19A–D). Empodial claws absent. One pair of duplex setae on tarsus I, sometimes setal bases of ft′ and ω′ separated, solenidion ω′ 5, one additional ventral solenidion (vω) at the same level with u setae, 8 long, tectal seta (tc′) unpaired, thicker than other tactile setae on tarsus I; tibia I with one solenidion φ 7 long; tarsus II without duplex setae, solenidion ω″ 6 long, tectal seta (tc′), thicker than other tactile setae; tarsus III and tarsus IV without solenidion. Number of tactile setae on leg (I–IV) segments: trochanters 0-0-0-0, femora 3-3-1-1, genua 1-1-0-0, tibiae 3-1-1-1, tarsus 5-5-6-6. Number of eupathidia on tarsus I–V: 3-3-0-0. Legs I–IV setation and notation as shown in Figure 19A–D. Length of leg segments: femur I 32, genu I 17, tibia I 16, tarsus I 28; femur II 26, genu II 15, tibia II 15, tarsus II 28; femur III 25, genu III 13, tibia III 15, tarsus III 32; femur IV 22, genu IV 11, tibia IV 12, tarsus IV 29.

As we do not have the larva to examine, we cannot determine which setae are added to the legs in the protonymph, although based on what is already known for the ontogenetic setal additions for the family, it would appear that the protonymph maintains the larval chaetotaxy on femora I–IV, genua I–IV, tibiae I–IV and tarsus III–IV, adding only the tectal (tc″) to tarsus I–II and ω′ to tarsus I, as is normal for the family. A total of 34 setae are suppressed on legs I–IV in the larval-protonymphal stage of this species: three on genua I, two on tibia I, four on tarsus I, three on genua II, four on tibia II, two on tarsus II, one on femur III, two on genua III, four on tibia III, two on tarsus III, one on femur IV, two on genua IV, and four on tibia IV.

3.3. New Species

Family Tetranychidae Donnadieu

Subfamily Tetranychinae Berlese

Tribe Aponychini Rimando & Corpuz-Raros

Genus Stylophoronychus Prasad

Stylophoronychus wangaePan, Jin & Yi sp. nov.

Material examined. Holotype, one female, ex. bamboo, from Majiang Country, Guizhou Province, China, on 3 August 2020, coll. Tian-Ci Yi. Paratype, 14 females, three males, one deutonymph, the same data as the holotype. All deposited at the Institute of Entomology, Guizhou University, Guiyang, P.R. China (GUGC).

Etymology. The name of the new species is named after the late Professor Huifu Wang in honor of her contributions to Acarology in China.

Description

Figure 20, Figure 21, Figure 22, Figure 23, Figure 24, Figure 25, Figure 26, Figure 27, Figure 28, Figure 29, Figure 30, Figure 31, Figure 32, Figure 33, Figure 34, Figure 35 and Figure 36

Female (n = 15)

Dorsum (Figure 20, Figure 21 and Figure 22). Body oblong, 359 (311–366) long excluding gnathosoma, 495 (422–506) including gnathosoma, 277 (251–277) wide. Color: brownish yellow, with some black patches on the dorsum and two pairs of red eyes. Dorsocentral region idiosoma with a distinct convex protuberance. Integument finely granulate and with irregular striae. Prodorsum with three pairs of setae (v₂, sc₁, sc₂), seta v₂ spatulate, on two slightly developed anterior lobes, two times as long as wide, more than twice as long as sc₁, seta sc₁ smaller, fan-shaped; setae sc₂ set on strong tubercles, linear, all covered with short barbs; v₂ 26 (25–30), sc₁ 14 (12–15), sc₂ 59 (50–62), v₂–v₂ 87 (81–90), sc₁–sc₁ 129 (120–129), sc₂–sc₂ 244 (222–244).

Hysterosomal dorsum with convex bulge that bears setae c₁, d₁ and e₁, oblique wide ridges laterally, full of irregular wrinkles and finely granulated; the dorsocentral setae (c₁, d₁, e₁) long linear, similar in shape to sc₂, the dorsolateral setae (c₂, d₂, e₂) are greatly different in morphology and size, setae c₂ and d₂ spatulate but the former smaller, seta e₂ long linear; setae e₂, f₂, h₁ are nearly the same length and similar in shape to the dorsocentral setae. The length of dorsal central setae (c₁, d₁, e₁) is equal to or longer than the distances between the seta and the next setal row (c₁–d₁, d₁–e₁). Length of dorsal setae: c₁ 68 (53–68), c₂ 13 (11–13), c₃ 62 (54–62), d₁ 66 (56–72), d₂ 19 (15–23), e₁ 56 (45–57), e₂ 61 (52–61), f₂ 57 (53–62), h₁ 58 (48–58); distance between dorsal setae: c₁–c₁ 39 (39–47), c₂–c₂ 168 (151–175), c₃–c₃ 277 (251–277), d₁–d₁ 54 (41–54), d₂–d₂ 221 (206–230), e₁–e₁ 42 (35–44), e₂–e₂ 165 (150–165), f₂–f₂ 115 (99–115), h₁–h₁ 60 (53–60), c₁–d₁ 53 (39–53), d₁–e₁ 61 (41–67), e₂–f₂ 118 (103–120), e₁–h₁ 40 (33–40).

Venter (Figure 23 and Figure 24). Striae mostly transverse, pregenital striae with discontinuous slight fine lines. Genital flap with transverse striae, oblique striae anterior-laterally, longitudinal medially and transverse striae posteriorly. All ventral setae thin and smooth. Setae 1a, 3a and 4a shorter than distance between their bases, respectively. Coxal setal count 2-1-1-1, one pair of anal setae (ps₁), two pairs of genital setae (g_1–2). Length of ventral setae: 1a 18 (16–20), 3a 22 (12–23), 4a 15 (15–19), 1b 25 (23–28), 1c 28 (26–31), 2b 22 (17–28), 3b 17 (17–28), 4b 26 (22–26); distance between intercoxal and coxae setae: 1a–1a 22 (21–27), 3a–3a 59 (55–67), 4a–4a 82 (53–82); aggenital setae: ag 13 (9–15), ag–ag 17 (17–21); genital setae: g₁ 31 (29–31), g₂ 40 (34–40), g₁–g₁ 25 (24–28), g₂–g₂ 55 (49–55); anal setae one pair: ps₁ 14 (10–14), ps₁–ps₁ 28 (18–28); para-anal setae two pairs h₂ 31 (25–32), h₃ 32 (27–32), h₂–h₂ 57 (28–57), h₃–h₃ 77 (48–77).

Gnathosoma (Figure 25 and Figure 30C). Stylophore with longitudinal striae, having two strong lobes distally. Ventral infracapitular setae m smooth, 19 (14–19) in length. m–m 34 (31–34). Palp setation and notation as shown in Figure 25. Palptarsus: terminal eupathidium (suζ) elongate, blunt tipped, 4.4 (3.5–5.8) in length, 2.4 (2.2–2.9) in width; two lateral eupathidia (ul′ζ and ul″ζ) subequal in length, 4.8 (4.2–5.8); one solenidion (ω), 3.1 (2.2–3.1); three tactile setae: a 4.5 (4.5–6.3), b 5.3 (5.3–6.5), c 7.5 (4.9–7.6). Measurements of setae on other palp segments: dPFe 36 (32–38), l″PGe 17 (17–19), dPTi 11 (7–11), l′PTi 12 (9–12), l″PTi 14 (14–18). Peritreme slightly enlarged at distal end (Figure 30C).

Legs (Figure 26). Tarsus I with one pair of duplex setae and one additional ventral solenidion (vω) at the same transverse level with u. Two solenidia vω 12 (11–14), ω′ 13 (9–13), single tc on tarsus I (tc″ absent); tibia I with one solenidion φ 13 (12–14) long; tarsus II with one solenidion ω″ 12 (11–12) long; tarsi III and IV with one solenidion ω′ 8 (7–10), ω′ 6 (6–10), respectively. Segmental length of legs: leg I: trochanter 31 (27–32), femur 95 (93–102), genua 51 (45–51), tibia 58 (46–58), tarsus 80 (65–84); leg II: trochanter 26 (20–27), femur 79 (75–80), genu 44 (38–47), tibia 43 (35–43), tarsus 70 (57–76); leg III: trochanter 26 (20–26), femur 72 (62–72), genua 38 (33–38), tibia 50 (41–50), tarsus 80 (68–81); leg IV: trochanter 31 (24–31), femur 98 (84–98), genua 44 (38–44), tibia 56 (50–56), tarsus 92 (79–92); legs chaetotaxy I–IV (eupathidia and solenidia in parentheses): trochanters 1-1-1-1, femora 6-5-3-1, genua 2-1-1-1, tibiae 3(0)(1)-2-1-1, tarsi 6(3)(2)-6(3)(1)-6(0)(1)-6(0)(1).

Male (n = 3)

Dorsum (Figure 27 and Figure 28). Idiosoma subovate, narrowing posteriorly, brownish yellow, with some black pathes on the dorsum and two pairs of red eyes. Length of idiosoma 208 (208–217) long excluding gnathosoma, 271 (271–274) including gnathosoma, 183 (183–189) wide. Hysterosoma dorsally with irregular fine granulate, except for band of transverse striae between paired c₁, d₁ and e₁. The 13 pairs of dorsal setae shorter than those of female, mostly spatulate. Length of dorsal setae: v₂ 17 (17–20), sc₁ 10 (10–11), sc₂ 18 (17–18), c₁ 16 (16–20), c₂ 7, c₃ 27 (27–30), d₁ 15 (15–17), d₂ 13 (11–13), e₁ 17 (14–17), e₂ 20 (20–29), f₂ 28 (28–29), h₁ 26; distance between dorsal setae: v₂–v₂ 60 (59–60), sc₁–sc₁ 87, sc₂–sc₂ 178 (177–178), c₁–c₁ 21 (19–21), c₂–c₂ 99 (99–102), c₃–c₃ 173 (162–173), d₁–d₁ 33 (29–33), d₂–d₂ 117 (110–117), e₁–e₁ 19 (18–19), e₂–e₂ 83 (83–86), f₂–f₂ 64, h₁–h₁ 37 (37–38), c₁–d₁ 26 (26–31), d₁–e₁ 31 (29–31), e₁–f₂ 59 (56–59), f₂–h₁ 19 (17–19).

Venter (Figure 29). Striae mostly transverse. All ventral setae thin and smooth. Setae 1a, 3a and 4a shorter than distance between their bases respectively. Coxal setal count 2-1-1-1, one pair of anal setae (ps₁), two pairs of genital setae (g_1–2). Length of ventral setae: 1a 20, 3a 20, 4a 14 (14–17), 1b 19 (19–23), 1c 17 (17–22), 2b 16 (16–23), 3b 20 (20–24), 4b 20 (18–20); distance between intercoxal and coxae setae: 1a–1a 22 (19–22), 3a–3a 43 (38–43), 4a–4a 32 (32–37); aggenital setae: ag 16 (15–16), ag–ag 5 (5–6); genital setae: g₁ 5 (5–7), g₂ 8, g₁–g₁ 17 (13–17), g₂–g₂ 29 (25–29); anal setae one pair: ps₁ 8 (8–9), ps₁–ps₁ 20; para-anal setae two pairs h₂ 12 (6–12), h₃ 12 (12–13), h₂–h₂ 15 (15–18), h₃–h₃ 35 (35–37).

Gnathosoma (Figure 27, Figure 30A,B and Figure 31). Stylophore with short bilobed horn-like anterior projections as shown in Figure 27. Subcapitular setae m smooth, 16 (13–16) in length, m–m 28 (27–28). Palp setation and notation as shown in Figure 31. Palptarsus: terminal eupathidium (suζ) elongate, blunt tipped, 3.4 (3.4–3.8) in length, 1.6 (1.4–1.6) in width; two lateral eupathidia (ul′ζ and ul″ζ) subequal in length, 3.9 (3.8–3.9); one solenidion (ω), 2.4 (2.4–2.5); three tactile setae: a 3.8 (3.8–5.3), b 3.8 (3.8–6.5), c 3.4. Measurements of setae on other palp segments: dPFe 17 (15–17), l″PGe 9 (9–11), dPTi 6.5 (6.5–10.1), l′PTi 8.9 (8.9–9), l″PTi 7.9 (6.9–10.8). Peritreme ending in small expansion (Figure 30A,B).

Aedeagus (Figure 30E,F). Aedeagus dorsally curved, gradually narrowing and distally dipping upturned forming an acute angle, blunt tipped.

Legs (Figure 32). Tarsus I with one pair of duplex setae, one additional ventral solenidion (vω) and one additional dorsal solenidion ω″₁, three solenidia, ω′ 14 (13–14), vω 11 (11–13) long, ω″₁ 13 (13–14) long; tibia I with three solenidia, φ 14 (9–14), φ′ 11 (11–13), φ″ 14 (14–16) long; tarsus II with two solenidia ω″ 16 (13–16), ω″₁ 12 long; tibia II with one solenidion, φ 10 (10–12); tarsi III and IV with one solenidion ω′ 12 (11–12), ω′ 10 (9–10), respectively. Segmental length of legs: leg I: trochanter 27, femur 86 (86–94), genua 53 (53–54), tibia 58 (58–60), tarsus 67 (67–72); leg II: trochanter 22, femur 70 (70–77), genua 46 (46–47), tibia 48 (47–48), tarsus 59 (59–68); leg III: trochanter 20 (20–22), femur 63 (63–65), genua 33 (33–37), tibia 49 (49–50), tarsus 72 (72–74); leg IV: trochanter 26 (22–26), femur 81 (81–87), genua 41, tibia 55 (55–56), tarsus 72 (72–80); legs chaetotaxy I–IV (eupathidia and solenidia in parentheses): trochanters 1-1-1-1, femora 7-5-3-1, genua 3-3-1-1, tibiae 3(0)(3)-2(0)(1)-1-1, tarsi 6(3)(3)-6(3)(2)-6(0)(1)-6(0)(1).

Deutonymph (n = 1)

Dorsum (Figure 33). Length of idiosoma 243 long excluding gnathosoma, 300 including gnathosoma, 211 wide. Integument finely granulated, having irregular wrinkles, slightly uplifted in the middle. The shape of dorsal setae similar to female and the length of dorsal central setae (c₁, d₁, e₁) is much longer than the distances between bases of setae and setae in next row (c₁–d₁, d₁–e₁). Length of dorsal setae: v₂ 48, sc₁ 13, sc₂ 43, c₁ 55, c₂ 9, c₃ 43, d₁ 58, d₂ 18, e₁ 42, e₂ 46, f₂ 47, h₁ 44; distance between dorsal setae: v₂–v₂ 66, sc₁–sc₁ 107, sc₂–sc₂ 205, c₁–c₁ 40, c₂–c₂ 141, c₃–c₃ 211, d₁–d₁ 42, d₂–d₂ 180, e₁–e₁ 31, e₂–e₂ 119, f₂–f₂ 82, h₁–h₁ 44, c₁–d₁ 28, d₁–e₁ 34, e₂–f₂ 21, e₁–h₁ 90.

Venter (Figure 34). Ventral striae mostly transverse except for pregenital area with longitudinal striae, oblique striae anterior-laterally, longitudinal medially and transverse striae posteriorly. All ventral setae thin and smooth. Setae 1a, 3a and 4a shorter than distance between their bases, respectively. Coxal setal count 2-1-1-1, one pair of anal setae (ps₁), two pairs of genital setae (g_1–2). Length of ventral setae: 1a 11, 3a 14, 4a 13, 1b 20, 1c 18, 2b 17, 3b 13, 4b 12; distance between intercoxal and coxae setae: 1a–1a 25, 3a–3a 45, 4a–4a 65; aggenital setae: ag 10, ag–ag 13; genital setae: g₁ 19, g₁–g₁ 31; anal setae one pair: ps₁ 7, ps₁–ps₁ 11; para-anal setae two pairs h₂ 14, h₃ 19, h₂–h₂ 19, h₃–h₃ 34.

Gnathosoma (Figure 30D, Figure 33 and Figure 35). Stylophore with two well-developed lobes distally as shown in Figure 33. Subcapitular setae m smooth, 13 in length, m–m 30. Palp setation and notation as shown in Figure 35. Palptarsus: terminal eupathidium (suζ) elongate, blunt tipped, 5.3 in length, 1.5 in width; two lateral eupathidia (ul′ζ and ul″ζ) subequal in length, 3.4; one solenidion (ω), 2.3; three tactile setae: a 4.3, b 3.2, c 3. Measurements of setae on other palp segments: dPFe 32, l″PGe 16, dPTi 7, l′PTi 7, l″PTi 16. Peritreme ending in small expansion (Figure 30D).

Legs (Figure 36). Similar to female except for missing one or two ventral tactile setae and one solenidion, tarsus I with one pair of duplex setae ω′ 7, and one additional ventral solenidion vω 8 long, tibia I with one solenidion, φ 9; tarsus II with one solenidion ω″ 8 long. Segmental length of legs: leg I: trochanter 20, femur 53, genua 30, tibia 28, tarsus 49; leg II: trochanter 16, femur 44, genua 24, tibia 24, tarsus 41; leg III: trochanter 17, femur 33, genua 20, tibia23, tarsus 49; leg IV: trochanter 17, femur 36, genua 20, tibia 22, tarsus 47; legs chaetotaxy I−IV (eupathidia and solenidia in parentheses): trochanters 1-1-1-0; femora 4-3-1-1; genua 2-1-0-0; tibiae 3(0)(1)-2-1-1; tarsi 4(3)(2)-4(3)(1)-5-5.

Key to species of Stylophoronychus (females)

• All dorsal setae club-like, coxal setal count 2-2-1-1...................S. insularis (Flechtmann)

  -

  Most dorsal setae long linear or spatulate, coxal setal count 2-1-1-1.....................2

• Hysterosoma with a central protuberance that arches upward, covered with an irregular pattern of circles or the fusion of many circles...........................S. vannus (Rimando)

  -

  Hysterosoma arched upward or not and without protuberance..............................3

• Length of c₁ and d₁ as long as, or longer than the distances between their respective setal bases and those of the setae in next row.................S. wangae Pan, Jin & Yi sp. nov.

  -

  Length of c₁ and d₁ less than the distances between their respective setal bases and those of the setae in next row................................................................................4

• Setae c₁, d₁ and e₁ decreasing in size successively..................S. nakaoi (Ehara & Wongsiri)

  -

  Setae c₁, d₁ and e₁ subequal in length...............................................S. baghensis (Prasad)

4. Discussion

Studying the ontogeny of spider mites will provide a better system for the classification and identification of these species. Several articles have been published to address this issue to reach a better understanding of the ontogenetic development of spider mites [11,12,13,14,15,16,17,18,19,20,21,22]. Previously, all species of Stylophoronychus were known only as adults; nothing was known of their ontogenetic development. Here, we discuss the ontogeny of the two species to give a preliminary insight into the evolution of the genus.

Ontogenetic development of S. vannus is mentioned in the description section above. Compared with the basic pattern of Tetranychinae described by Lindquist [10], the patterns of setation and setal additions on femura to the tarsi of legs I–IV in Stylophoronychus wangae sp. nov. have large amounts of setae suppressed.

Trochanters. The pattern and setal additions on the trochanter of legs I–IV in S. wangae sp. nov. follow the basic pattern for Tetranychinae described by Lindquist [10]. The seta v′ is absent on all legs of larval and protonymphal stages and present on deutonymphal trochanters I–III, but not on trochanter IV until reaching the adult stage.

Femora. The formula pattern of deutonymphal legs I–IV in S. wangae sp. nov. is 4-3-1-1, bearing three setae d, bv″, v′ and l′ on femur I, three setae d, bv″ and v′ on femur II, only d on femur III and IV. Two setae l″ and v″ are suppressed on leg I and ev′ is suppressed on leg III and leg IV compared with the date (6-3-2-2) of Lindquist [10]. The setal additional patterns only in adult femur I show sexual dimorphism—l′₁ and l″₁ are added to female femur I, while v″, l′₁ and l″₁ are added to male femur I; l′₁ and l″₁ are added to adult femur II; v′ and l′₁ added to adult femur III and none is added on femur IV. In total, six setae and seven setae are added to the femora of the female and male of this species, respectively, during ontogeny. Compared with the normal chaetotaxy of the female described by Lindquist [10], four setae l″, v″, v′₁ and v″₁ are absent on the female femur I of S. wangae sp. nov., v″₁ is suppressed on femur II, and ev′ is absent on legs III–IV. A total of four setae are suppressed on formula of deutonymphal stage and seven on adult female of this species.

Genua. The genual setation of deutonymphal legs I–IV in S. wangae sp. nov. is 2-1-0-0, l′ and l″ present on genu I, only l′ on genu II. The basic pattern of deutonymphal genual setation in Tetranychinae as described by Lindquist [10] is 5-5-3-3 in S. wangae sp. nov., three setae d, v′ and v″ are suppressed on genua I, four setae d, l″, v′ and v″ are suppressed on genu II, and genua III and IV each lack three setae (d, l′ and v′). Adult female genual setal count is similar to deutonymphal, except seta l′ is added on adult genua III–IV and the male has one more seta (v″) on the genu I and two more setae (l″ and v′) on the genu II than the female. In total, two setae and five setae are added to the genua of the female and male of this species, respectively, during ontogeny. Based on the basic adult genual of 5-5-4-4 in Lindquist [10], a total of 13 setae suppressed on genua of deutonymph and adult female respectively.

Tibiae. The tibial setation of deutonymphal legs I–IV in S. wangae sp. nov. is 3(1)-2-1-1, with three tactile setae (db, l′ and l″) and one solenidion (φ) on tibia I, two tactile setae (d and v′) on tibia II, and seta d on tibia III and IV, respectively. No seta is added in adult female; compared to female, two solenidia φ′ and φ″ are added on male tibia I and one solenidion (φ) is added on tibia II. In total, no setae and three solenidia are added to the tibiae of the female and male of this species, respectively, during ontogeny. Compared with the deutonymphal pattern of Tetranychinae described by Lindquist [10], four tactile setae (l′₁, l″₁, l′ and l″) suppressed on tibia I of S. wangae sp. nov., three tactile setae (l″, l′ and v″) suppressed on tibia II, and four tactile setae (d, l″, l′ and v″) suppressed on tibia III and IV, respectively. In the female adult, six tactile setae (l′, l″, l′₁, l″₁, v′₁ and v″₁) suppressed on tibia I, five tactile setae (l″, v′, v″, l′₁ and v′₁) suppressed on tibia II, five tactile setae (d, l″, l′, v″ and v′₁) suppressed on tibia III, six tactile setae (d, l″, v′, v″, l′₁ and v′₁) suppressed on tibia IV. A total of 15 setae are suppressed on tibiae of deutonymphal stage and 22 on adult female of this species.

Tarsi. All stages lack one ventral seta pv″, setae tc and ft unpaired on tarsi I–II, only present one seta tc′ but no tc″ and one fastigial seta ft′ but not ft″. In the deutonymph, four tactile setae (u′, u″, ft′ and tc′), three eupathidia (p′ζ, p″ζ and pv′ζ) and two solenidia(ω′ and vω) present on leg I; four tactile setae (u′, u″, ft′ and tc′), three eupathidia (p′ζ, p″ζ and pv′ζ) and one solenidion (ω″) on leg II, five tactile setae (u′, u″, ft′, ft″ and pv′) present on tarsus III–IV respectively. Adult female tarsal setae are similar to deutonymphal, except v′₁ and v″₁ are added on tarsi I–II, v″₁ and ω′ are added on tarsi III–IV and the male added one more seta (ω″₁) than the female on tarsi I–II. In total, no setae and three solenidia are added to the tarsi of the female and male of this species, respectively, during ontogeny.

Compared with the basic pattern of Tetranychinae described by Lindquist [10], it appears that six tactile setae (ft″, tc″, l′, l″, v′₂ and pv″) and one solenidion (ω″₁) are suppressed on deutonymphal leg I of S. wangae sp. nov., four tactile setae (ft″, tc″, v″₁ and pv″) suppressed on leg II, three tactile setae (tc′, tc″ and pv″) and one solenidion (ω′) suppressed on leg III, three tactile setae (tc′, tc″ and pv″) are suppressed on leg IV and, in total, 18 setae are suppressed on deutonymphal legs I–IV in S. wangae sp. nov. In the adult female, seven setae (ft″, tc″, l′, l″, v′₂, pv″ and ω′) are suppressed on tarsus I; six setae (ft″, tc″, l′, v′₂, pv″ and ω″₁) are suppressed on tarsus II; three setae (tc′, tc″ and pv″) are suppressed on tarsus III; four setae (tc′, tc″, v′₁ and pv″) are suppressed on tarsus IV. In total, 20 setae are suppressed on adult female legs I–IV in S. wangae sp. nov.

Compared with the data presented by Lindquist [10] for the Tetranychidae, there are several differences during the ontogeny of two species of Stylophoronychus, as follows:

(1)

Two additional setae, ventral solenidion (vω) on tarsus I and ventral seta (v″₁) on tarsus III in male of S. vannus and S. wangae sp. nov., do not express setal standard for the Tetranychidae;

(2)

Unpaired tectal seta (tc′) and fastigial seta (ft′) present on tarsi I and II, and paired are tc suppressed on tarsus III and IV in two species and unpaired ventral seta pv″ presents in S. wangae sp. nov.;

(3)

Seta ev′ is suppressed on femur III and IV;

(4)

Seta v′ on trochanter IV is suppressed in deutonymph and delayed additions in adult.