Morphological ontogeny in Tenuipalpus orilloi Rimando (Acari: Tenuipalpidae) Author Xu, Yun Author Zhu, Yu-Zhen Author Wu, Jie-Qin Author Zhang, Fei-Ping text Zootaxa 2019 2019-12-31 4717 1 185 205 journal article 24452 10.11646/zootaxa.4717.1.11 88e362dd-04a7-4975-b2a1-2d61716d6a57 1175-5326 3601952 CA80A558-1D76-406F-90C2-89F66F01CDB1 Tenuipalpus orilloi Rimando ( Figs. 1 –18) Redescription Female ( Figs. 1–2 ) As described by Xu and Fan (2010) with supplementary data from new specimens as follows. Length 275–290, width 165–170. Prodorsum divided into 3 regions by two strong longitudinal wrinkles; covered with transverse striations mesally, oblique striations laterally becoming stronger posteriorly, and 4 pairs of porous patches and strong wrinkles submarginally; setae v 2 and sc 1 minute and oblanceolate, sc 2 elongate and falcate. Setal lengths: v 2 8–10 , sc 1 9–10 , sc 2 42–47; distances: v 2 – v 2 35 – 37, v 2 – sc 1 35–40, sc 1 – sc 1 87–90, sc 1 – sc 2 37–40, sc 2 – sc 2 165–170. Hysterosoma with two short, strong longitudinal wrinkles laterad of c 1 and d 1 ; with transversal wrinkles medially between c 1 – e 1 ; cuticle posterior to setae e 1 with irregular striations becoming smooth posteriorly; few porous patches longitudinally aligned submarginally; setae c 1 , d 1 , e 1 and d 3 minute, oblanceolate; c 3 , e 3 , f 2 , f 3 and h 1 oblanceolate to weakly falcate, and h 2 flagellate. Setal lengths: c 1 5–6, c 3 13–16 , d 1 5–6, d 3 11–15 , e 1 6 –10, e 3 11 –22, f 2 22–27 , f 3 22–30 , h 1 16–20 , h 2 200–225; distances: c 1 – c 1 50–58, c 3 – c 3 180–195, d 1 – d 1 31–38 , d 3 – d 3 150–170, e 1 – e 1 25 –27, e 3 – e 3 125–130, d 3 – e 3 67–75, e 3 – f 2 25–32 , f 2 – f 2 115–125, f 3 – f 3 93–105, f 2 – f 3 17–23 , f 3 – h 2 15–18 , h 2 – h 2 72–80, h 1 – h 1 35–40, h 2 – h 1 17–22 . Venter from 1a–4a with fine broken longitudinal striae. Genital and ventral area fused into one plate with fine, irregularly transverse broken cuticles. Setal lengths: 1a 110–135, 1b 16–18, 1c 19–21, 2b 17–18, 2c 22–25, 3a 13–17, 3b 20–22, 4a 17–20, 4b 15–19, ag 21–25, g 1 18–22 , g 2 20–22 , ps 1 28–31 , ps 2 9–11 ; distances: 1a–1a 29–31, 3a–3a 53–58, 4a–4a 37–44, ag–ag 24–25, g 1 – g 1 27–33 , g 1 – g 2 14–16 , g 2 – g 2 62–66, ps 1 – ps 2 4–5. Lengths of legs I–IV: 140–145, 120–125, 110–115, 120–125. Setal counts: coxae 2 ( 1b , 1c )-2 ( 2b , 2c )-1 ( 3b )-1 ( 4b ); trochanters 1 ( v′ )-1 ( v′ )-2 ( v′ , l′ )-1 ( v′ ); femora 4 ( d , v′ , bv′′ , l′ )-4 ( d , v′ , bv′′ , l′ )-2 ( d , ev′ )-1 ( ev′ ); genua 3 ( d , l’’ , l′ )-3 ( d , l’’ , l′ )-1 ( l′ )-1 ( l′ ); tibiae 5 ( d , v′ , v′′ , l′ , l′′ )-5 ( d , v′ , v′′ , l′ , l′′ )-3 ( d , v′ , v′′ )-3 ( d , v′ , v′′ ); tarsi 9 ( u′ , u’’ , p’ζ , p”ζ, ft’ , ft’’ , tc′ , tc′′ , ω′′ )-9 ( u′ , u’’ , p’ζ , p’’ζ , ft’ , ft’’ , tc′ , tc′′ , ω′′ )-5 ( ft’ , u′ , u’’ , tc′ , tc′′ )-5 ( ft’ , u′ , u’’ , tc′ , tc′′ ). Lengths of solenidia: tarsus I ω’’ 13–14; tarsus II ω’’ 13–14. Male Gnathosoma . Infracapitulum reaching proximally one fourth of femur I, subcapitular setae m pectinate, m = 13, m–m = 19. Palp 3-segmented, tarsi with one eupathidium 6 long. Idiosoma . ( Fig. 3 ) Length 240, width 140. Anterior margin with one median bifurcate projection. Prodorsal setae v 2 and sc 1 acicular and minute, sc 2 lanceolate to weakly falcate, 7 times as long as v 2 . Prodorsum divided into 3 regions by two strong longitudinal wrinkles. Setal lengths: v 2 5, sc 1 5, sc 2 35; distances: v 2 – v 2 33 , v 2 – sc 1 30, sc 1 – sc 1 73, sc 1 – sc 2 35, sc 2 – sc 2 140. Hysterosoma divided into metapodosoma and opisthosoma by few faint transverse folds. Opisthosoma with few oblique striations anterior to e 1 and few lateral broken striae posterior to e 1 . All dorsolateral setae lanceolate except h 2 flagelliform. Setal lengths: c 1 2, c 3 9, d 1 4, d 3 7, e 1 3 −5, e 3 9 , f 2 16, f 3 13, h 1 13, h 2 95; distances: c 1 – c 1 38, d 1 – d 1 30, e 1 – e 1 15 , c 3 – c 3 135, d 3 – d 3 110, d 3 – e 3 53 , e 3 – e 3 82, e 3 – f 2 31, f 2 – f 2 75, f 2 – f 3 18, f 3 – f 3 65, f 3 – h 2 14, h 2 – h 2 48, h 2 – h 1 13, h 1 – h 1 23. Venter ( Fig. 4 ). Venter similar to female. All coxal setae acicular. Seta 1a flagelliform, 3a and 4a acicular, 1a about 4 times as long as 4a . Setal lengths: 1a 68, 1b 17, 1c 20, 2b 17, 2c 23, 3a 19, 3b 20, 4a 16, 4b 22; distances: 1a–1a 22, 3a–3a 40, 4a–4a 29. Ventral area with transversal cuticles between 4a and g 1 , aggenital setae ( ag ) and genital setae ( g 1 and g 2 ) acicular. Pseudanal setae ps 1 acicular, ps 2 modified into accessory genital stylets, inserted terminally on elongate genital valve. A narrow, elongate, sclerotised aedeagus; membranous duct emerging from aedeagus and terminating in flared, lightly sclerotised cup distally, appearing to open into a soft membranous vesicle ( Fig. 6C ). Setae lengths: ag 20, g 1 17, g 2 20, ps 1 15, ps 2 8; distances: ag–ag 15, g 1 – g 2 3. Legs ( Figs. 5 , 6A, B ). Lengths of legs I–IV: 95, 85, 68, 80. Setal counts: coxae 2-2-1-1; trochanters 1-1-2-1; femora 4-4-2-1; genua 3-3-1-1; tibiae 5-5-3-3; tarsi 8+2 ω -8+2 ω -5-5. Most dorsal and lateral setae on femora, genua and tibiae narrowly elongate lanceolate to oblanceolate; ventral setae pectinate. Tarsal setae ft’ flagelliform, much longer than other setae, ft’’ short, lanceolate; unguinal setae ( u ) pectinate and tectal setae ( tc ) acicular. Solenidion ω and eupathidia pζ rod-like. Lengths of solenidia: tarsus I ω’’ 18, ω’ 16; tarsus II ω’’ 16, ω’ 16. True claws short rod-shaped, with tenent hairs on each side. FIGURE 1. Tenuipalpus orilloi (adult female). dorsal view of idiosoma. FIGURE 2. Tenuipalpus orilloi (adult female). Ventral view of idiosoma. FIGURE 3. Tenuipalpus orilloi (adult male emerging from deutonymphal skin). Dorsal view of idiosoma. Notes: The measurements of male provided herein may vary, since the specimen described is emerging from the deutonymph skin. Deutonymph Gnathosoma ( Fig. 9E ). Infracapitulum reaching distal end of trochanter I, subcapitular setae m acicular, m = 8–12, m–m = 16–20. Palp 3-segmented, tarsi with one eupathidium 5–6 long. Idiosoma ( Fig. 7 ). Length 240–330, width 170–225. Anterior margin with one median bifurcate projection. Prodorsal setae v 2 and sc 1 acicular and minute, sc 2 narrowly elongate lanceolate. Prodorsum with smooth central region. Setal lengths: v 2 2–4, sc 1 2–4, sc 2 53–60; distances: v 2 – v 2 31–37 , v 2 – sc 1 28–34 , sc 1 – sc 1 75–87, sc 1 – sc 2 33–43, sc 2 – sc 2 140–170. Hysterosoma with faint transversal striations from sc 2 to d 1 and with few short oblique striations between d 1 and d 3 ; Most dorsolateral setae narrowly elongate lanceolate except c 1 , d 1 , d 3 and e 1 minute acicular, and h 2 flagelliform. Setal lengths: c 1 2–3, c 3 32–37, d 1 2–3, d 3 2–4, e 1 2 –4, e 3 26 –36, f 2 26–35 , f 3 25–35 , h 1 14–28 , h 2 95–130; distances: c 1 – c 1 35–42, c 3 – c 3 150–200, d 1 – d 1 18–26 , d 3 – d 3 115–155, e 1 – e 1 13 –20, e 3 – e 3 82–110, d 3 – e 3 45 –55, e 3 – f 2 13–14 , f 2 – f 2 75–95, f 3 – f 3 60–79, f 2 – f 3 13–17 , f 3 – h 2 13–18 , h 2 – h 2 40–50, h 1 – h 1 19–22 , h 2 – h 1 11–13 . Venter ( Fig. 8 ). Venter with fine transverse striations. All coxal setae fine, acicular. Seta 1a and 4a flagelliform and subequal in length; 3a fine, acicular; 1a 7 times as long as 3a . Setal lengths: 1a 70–88, 1b 8–10, 1c 8–10, 2b 7–10, 2c 12–17, 3a 8–10, 3b 11–13, 4a 34–48, 4b 9–11; distances: 1a–1a 16–25, 3a–3a 37–47, 4a–4a 27–33. Aggenital setae ag , genital setae g 1 , pseudanal setae ( ps 1 and ps 2 ) all short, fine, acicular, subequal in length. Setae lengths: ag 9–10, g 1 7–9, ps 1 4–7, ps 2 5–7; distances: ag–ag 14–19, g 1 – g 1 15–23 , ps 1 – ps 2 7–10 . Legs ( Fig. 9 A–D). Lengths of legs I–IV: 79–92, 61–80, 51–64, 50–62. Setal counts: coxae 2-2-1-1; trochanters 1-1-2-0; femora 4-4-2-1; genua 3-3-1-0; tibiae 5-5-3-3; tarsi 8+ ω -8+ ω -5-3. Most dorsal and lateral setae on femora, genua and tibiae narrowly elongate lanceolate; setae l’ on tibia I–II acicular; ventral setae on femora and tibiae pectinate; bv’’ on femora II elongate lanceolate. Tarsal setae ft’ flagelliform, much longer than other setae, ft’’ short lanceolate; unguinal setae ( u ) pectinate and tectal setae ( tc ) acicular. Solenidion ω and eupathidia pζ rod-like. Lengths of solenidia: tarsus I ω’’ 6–8; tarsus II ω’’ 6–8. True claws short rod-shaped, with tenent hairs on each side. Protonymph Gnathosoma ( Fig. 12E ). Infracapitulum reaching proximally one third of femur I, subcapitular setae m acicular, m = 5−7, m–m = 12−16. Palp 3-segmented, tarsi with one eupathidium 4 long. Idiosoma ( Fig. 10 ). Length 245−260, width 170−180. Anterior margin with one median bifurcate projection. Prodorsum similar to deutonymph, prodorsal setae v 2 and sc 1 acicular and minute, sc 2 narrowly elongate lanceolate. Setal lengths: v 2 2−8, sc 1 3, sc 2 43−47; distances: v 2 – v 2 26−29 , v 2 – sc 1 27−30 , sc 1 – sc 1 67−72, sc 1 – sc 2 31−33 , sc 2 – sc 2 125−140. Most lateral dorsal setae narrowly elongate lanceolate except c 1 , d 1 , d 3 , e 1 minute and h 2 flagelliform. Setal lengths: c 1 2−3, c 3 25−30 , d 1 2−3, d 3 3−4, e 1 2 −5, e 3 24 −28, f 2 25−28 , f 3 26−28 , h 1 19−25 , h 2 83−95; distances: c 1 – c 1 34−37, c 3 – c 3 150−160, d 1 – d 1 16−25 , d 3 – d 3 105−110, e 1 – e 1 11 −15, e 3 – e 3 74−85, d 3 – e 3 31 −39, e 3 – f 2 7−9, f 2 – f 2 66−73, f 3 – f 3 54−62, f 2 – f 3 8−11 , f 3 – h 2 11−16 , h 1 – h 1 17−19 , h 2 – h 2 35−40, h 2 – h 1 8−10 . Venter ( Fig. 11 ). Venter similar to deutonymph. All coxal setae acicular. Seta 1a flagelliform, 3a acicular. Setal lengths: 1a 68−95, 1b 8−13, 1c 8−11, 2c 10−12, 3a 8−10, 3b 9−13; distances: 1a–1a 18−19, 3a–3a 38−42. Aggeni- tal setae ag and pseudanal setae ( ps 1 and ps 2 ) acicular. Setal lengths: ag 6−10, ps 1 3−4, ps 2 3−4; distances: ag–ag 15−19, ps 1 – ps 2 5−7. Legs ( Fig. 12 A–D). Lengths of legs I–IV: 64−65, 52−55, 45−50, 40−41. Setal counts: coxae 2-1-1-0; trochan- ters 0-0-1-0; femora 3-3-2-1; genua 1-1-0-0; tibiae 5-5-3-3; tarsi 6+ ω -6+ ω -3-3. Most dorsal and lateral setae on femora, genua and tibiae elongate, narrowly lanceolate to linear; setae l’ on tibia I−II acicular; ventral setae acicular, except on femora I−II pectinate and bv’’ on femora II narrowly elongate lanceolate to linear. Tarsal setae ft’ flagelliform, much longer than other setae, ft’’ short, lanceolate; unguinal setae ( u ) pectinate. Solenidion ω and eupathidia pζ rod-shaped. Lengths of solenidia: tarsus I ω’’ 5, tarsus II ω’’ 4−5. True claws short rod-shaped, with tenent hairs on each side. Larva Gnathosoma . Infracapitulum reaching distal end of femur I, subcapitular setae m absent. Palp 3-segmented, tarsi with one eupathidium 3−4 long. FIGURE 4. Tenuipalpus orilloi (adult male emerging from deutonymphal skin). Ventral view of idiosoma. FIGURE 5. Tenuipalpus orilloi (adult male emerging from deutonymphal skin, left side legs). A, leg I trochanter to tibia; B, leg I tarsus; C, leg II trochanter to tibia; D, leg II tarsus. FIGURE 6. Tenuipalpus orilloi (adult male emerging from deutonymphal skin, left side legs). A, leg III; B. leg IV; C. aedeagus. FIGURE 7. Tenuipalpus orilloi (deutonymph). Dorsal view of idiosoma. FIGURE 8. Tenuipalpus orilloi (deutonymph). Ventral view of idiosoma. FIGURE 9. Tenuipalpus orilloi (deutonymph, left side legs). A, leg I; B, leg II; C, leg III; D, leg IV; E. palp. FIGURE 10. Tenuipalpus orilloi (protonymph). Dorsal view of idiosoma. FIGURE 11. Tenuipalpus orilloi (protonymph). Ventral view of idiosoma. FIGURE 12. Tenuipalpus orilloi (protonymph, left side legs). A, leg I; B, leg II; C, leg III; D, leg IV; E, palp. FIGURE 13. Tenuipalpus orilloi (larva). Dorsal view of idiosoma. FIGURE 14. Tenuipalpus orilloi (larva). Ventral view of idiosoma. FIGURE 15. Tenuipalpus orilloi (larva, right side legs). A, leg I; B, leg II; C, leg III. Idiosoma ( Fig. 13 ). Length 165−180, width 130−135. Anterior margin rounded without median projection. Prodorsum with central region of finely pustulate cuticle; prodorsal setae v 2 and sc 1 acicular and minute, sc 2 narrowly elongate lanceolate to linear. Setal lengths: v 2 2−3, sc 1 2−3, sc 2 32−37; distances: v 2 – v 2 23−26 , v 2 – sc 1 24−29 , sc 1 – sc 1 59−65, sc 1 – sc 2 22, sc 2 – sc 2 100−110. Hysterosoma with most dorsal setae narrowly elongate lanceolate to linear, except c 1 , c 3 , d 1 , d 3 and e 1 minute and h 2 flagelliform. Setal lengths: c 1 2, c 3 16−23 , d 1 2, d 3 2, e 1 2 −3, e 3 20 −28, f 2 19−27 , f 3 19−23 , h 1 17−21 , h 2 82−90; distances: c 1 – c 1 30−35 , c 3 – c 3 115−120, d 1 – d 1 16−19 , d 3 – d 3 72−80, e 1 – e 1 8 −10, e 3 – e 3 70−78, d 3 – e 3 10 −11, e 3 – f 2 8, f 2 – f 2 62−68, f 3 – f 3 49−53, f 2 – f 3 8−10 , f 3 – h 2 8−11 , h 2 – h 2 33−36, h 1 – h 1 17−20 , h 2 – h 1 7−9. Venter ( Fig. 14 ). Venter similar to deutonymph and protonymph, with finely transverse striae. Seta 1a flagelliform, 3a fine, acicular. Setal lengths: 1a 33−45, 1b 6−8, 3a 7−8; distances: 1a–1a 15−19, 3a–3a 37−41. Pseudanal setae ( ps 1 and ps 2 ) acicular and subequal. Setal lengths: ps 1 2−5, ps 2 3−5; distances: ps 1 – ps 2 5−7. Legs ( Fig. 15 ). Lengths of legs I–III: 41−45, 36−41, 32−36. Setal counts: coxae 1-0-0; trochanters 0-0-0; femo- ra 3-3-2; genua 1-1-0; tibiae 5-5-3; tarsi 6+ ω -6+ ω -3. Most dorsal and lateral setae on femora, genua and tibiae narrowly elongate lanceolate to linear; setae l’ on tibia I−II acicular; ventral setae acicular. Tarsal setae ft’ flagelliform, much longer than other setae, ft’’ short, narrowly lanceolate; unguinal setae ( u ) petinate. Solenidia ω and eupathidia pζ rod-like. Lengths of solenidia: tarsus I ω’’ 4, tarsus II ω’’ 3−4. True claws short rod-shaped, with tenent hairs on each side. TABLE 1. Ontogeny of leg chaetotaxy of Tenuipalpus orilloi (setae are indicated where they are first added. Setae in parentheses represent pairs. Hyphen indicates no additions) .

Coxae	Trochanters	Femora	Genua	Tibiae	Tarsi
Leg I
Larva	1a , 1b	-	d , v′ , bv′′	l′	d , ( v ), ( l )	( u ), ( pζ ), ( ft ), ω′′
Protonymph	1c	-	-	-	-	-
Deutonymph	-	v′	l′	d , l’’	-	( tc )
Female	-	-	-	-	-	-
Male	-	-	-	-	-	ω′
Leg II
Larva	-	-	d , v′ , bv′′	l′	d , ( v ), ( l )	( u ), ( pζ ), ( ft ), ω′′
Protonymph	2c	-	-	-	-	-
Deutonymph	2b	v′	l′	d , l’’	-	( tc )
Female	-	-	-	-	-	-
Male	-	-	-	-	-	ω′
Leg III
Larva	3a	-	d , ev′	-	d , ( v )	( u ), ft′
Protonymph	3b	l′	-	-	-	-
Deutonymph	-	v′	-	l′	-	( tc )
Female	-	-	-	-	-	-
Male	-	-	-	-	-	-
Leg IV
Protonymph	-	-	ev′	-	d , ( v )	( u ), ft′
Deutonymph	4a , 4b	-	-	-	-	-
Female	-	v′	-	l′	-	( tc )
Male	-	v′	-	l′	-	( tc )

Remarks. Tenuipalpus orilloi belongs to the caudatus species group and anoplus subgroup of Meyer (1993) . With this subgroup, this species shares a well-developed and similarly shaped genitoventral plate with other four known Tenuipalpus species from the Asia-Pacific region: T. antipodus Collyer , T. gneti Xu et al . , T. guamensis Baker and T. palosapis Corpuz-Raros ( Castro et al. 2018 ; Xu et al. 2018; Xu and Zhang 2018 ). The leg setation and patterns of setal additions during ontogeny of leg setae for T. orilloi are exactly the same as those for T. gneti reported in Xu et al . (2018) ( Table 1 ). Tenuipalpus orilloi and T. gneti add seta l’ on trochanters III in the protonymph, and later add seta v’ on trochanters I–III in the deutonymph and on trochanters IV in the adult, which follows the standard pattern known so far for Tenuipalpidae ( Lindquist 1985 ; Welbourn et al. 2017 ). For the femora, there are two common patterns found in the larva and protonymph for the Tenuipalpidae (Welbourn et al . 2016) : 3-3-2-2 and 3-3-2-1. Setae d , v’ , bv’’ are present on femora I–II in the larva and protonymph, both setae d and ev’ are present on femora III, and either only ev’ ( d absent) or both d and ev’ are present on femur IV. Setae l’ are added later to femora I–II in the deutonymph. Additions to the genua appear to be variable in the genus Tenuipalpus , and the genual leg setation of T. orilloi and T. gneti shows ontogenetic delays when compared with data from Lindquist (1985) , Seeman and Beard (2011) ( Aegyptobia ), Beard et al . (2014) (various tegopalpine genera) and Welbourn et al . (2017) ( Tenuipalpus and related genera). Tenuipalpus orilloi , T. gneti and T. mahoensis , like both T. sarcophilus and T. toropi ( Welbourn et al. 2017 ) , follow the standard tenuipalpid pattern of additions for genua I–II by adding setae d and l″ in the deutonymph stage, but the additions to genua III–IV are delayed compared to the standard pattern. Tenuipalpus orilloi and T. gneti delay the addition of seta l′ to genu III, normally a larval seta, until the deutonymph, and delay the addition of l′ to genu IV until the adult (note that setae l′ on genua III–IV were referred to as setae d in Xu & Fan 2010 ). Lindquist (1985) stated that no setae are added to the genua of adult tenuipalpids, and this is true for adults of many taxa, but not all ( Welbourn et al. 2017 ; Beard et al. 2018 ). Adult Lisaepalpus break the rule by adding d to genua I–II and l′ to genu IV, adult Raoiella add l″ to genua I–II, adult T. orilloi and T. gneti , like Lisaepalpus , add l′ to genu IV, and adult T. antipodus add d to genua I–II. The tibial setation pattern that commonly occurs in the Tenuipalpus is 5-5-3-3, and as for the entire family, no setae are added to the tibiae during development ( Lindquist 1985 ). The patterns of additions to the tarsal setae are the most varied within the family Tenuipalpidae ( Welbourn et al . 2017 ) . The tectal setae ( tc ) are normally added to tarsi I–III in the protonymph and to tarsus IV in the deutonymph in many tenuipalpids. Tenuipalpus orilloi and T. gneti delay the addition of the tectal pair to tarsus I–III until the deutonymph, and to tarsus IV until the adult, as occurring in some other tenuipalpid taxa such as T. sarcophilus ( Welbourn et al. 2017 ) .