Tenuipalpus kitajimai, Castro & Beard & Ochoa & Bauchan & Feres, 2018

Castro, Elizeu B., Beard, Jennifer J., Ochoa, Ronald, Bauchan, Gary R. & Feres, Reinaldo J. F., 2018, Two new species of Tenuipalpus sensu stricto (Acari: Tenuipalpidae) from Brazil with a discussion on the ontogeny of leg setae, Zootaxa 4540 (1), pp. 178-210 : 194-208

Tenuipalpu s kitajimai sp. nov. Castro, Feres & Ochoa

( Figs 15–27 )

Diagnosis. Female: Prodorsal setae v2 and sc1 minute to short; sc2 elongate, lanceolate-falcate; dorsal opisthosoma with 10 pairs of setae (f2 present); most of the dorsal opisthosomal setae obovate (c1, c3, h1) to oblanceolate (e3, f2, f3), except setae d1, d3, e1 short to minute, thick, and h2 elongate, filiform; prodorsum with a pair of carinae converging posteriorly from setae sc1 to short central semicircular carina just anterior to shield margin and sejugal furrow; opisthosoma bearing a prominent transverse semicircular crest between setae c1–c1 and d1–d1 and one longitudinal crest between setae e1–e1; palp two segmented; two pairs of ps setae; one pair of 3a and 4a setae. Male: unknown. Immatures: deutonymphs and protonymphs bearing one pair median projections on anterior margin of prodorsum; with lateral body projections anterior and adjacent to setae sc2 present (lateral body projection posterior and adjacent setae c3 absent); dorsal setae similar to those of the female, except shorter. Larvae with colliculate cuticle on central prodorsum, dorsal opisthosoma posterior to setae d3 and e1, and over legs; setae v2, sc1, c1, d1, d3, e1 short to minute, other dorsal setae similar to those of female except smaller.

Dorsum ( Figs 15 –18). Anterior margin of prodorsal shield with two pairs of median lobes, central pair forming a forked projection with deep notch, lateral lobes forming two shallow notches. Prodorsum with one pair of rounded lateral projections anterior and adjacent to setae sc2; and anterior lateral margin of opisthosoma with a pair of rounded conical projections posterior and adjacent to setae c3; a pair of carinae converging posteriorly from setae sc1 to short central semicircular carina just anterior to shield margin and sejugal furrow ( Fig. 16a ). Opisthosoma with a prominent transverse semicircular cuticular crest between setae c1–c1 and d1–d1 and a longitudinal crest between setae e1–e1 ( Figs 16b , 17a , 18). Prodorsal setae v2 and sc1 minute to short and weakly barbed; sc2 elongate, lanceolate-falcate; most dorsal opisthosomal setae obovate (c1, c3, h1) to oblanceolate (e3, f2, f3), except d1, d3, e1 short to minute, thick, and h2 elongate filiform. Setal measurements: v2 5 (5–6), sc1 9 (7–9), sc2 70 (65–70), c1 38 (36–42), c3 36 (36–42), d1 6 (5–7), d3 7 (5–7), e1 7 (5–7), e3 55 (52–55), f2 45 (45–50), f3 45 (45–50), h1 31 (30–31), h2 100 (85–100).

Venter ( Figs 19 , 20 ). Ventral integument with fine transverse striae centrally and densely colliculate laterally; ventral and genital plates not thickened but membranous genital flap is present ( Figs 19 , 20 ) that appears to form part of a large membranous genito-ventral plate bearing setae ag, g1, g2 and clearly delimited laterally by the (longitudinal) folded cuticle of the ovipore ( Fig. 20 ), entire membranous plate with fine transverse striae; membranous anal valves with fine longitudinal striae; setae 1a, 4a filiform; coxal setae 1c, 2c, 3b, 4b and trochanter setae barbed; coxal setae 4b inserted much closer to 4a than 3b to 3a. Setal measurements: 1a 80 (75–80), 1b 10 (8–10), 1c 23 (21–23), 2b 17 (15–17), 2c 30 (27–30), 3a 8 (7–9), 3b 32 (28–31), 4a 60 (60–70), 4b 23 (20–25), ag1 12 (10–13), g1 22 (17–23), g2 16 (13–16), ps2 11 (7–11), ps3 12 (10–13).

Gnathosoma (Figs 21, 22). Palps two segmented, first (basal) segment short; second (distal) segment elongate and bearing one long, barbed seta d 11 (10–12) and two eupathidia, ul ′ 4 (3–4), ul ′′ 2 (1–2). Ventral infracapitulum setae m 13 (10–13); distance between setae m–m 19 (17–19).

Dorsum. Anterior margin of prodorsum with single pair of short central lobes, forming short notch; pair of rounded lateral body projections anterior and adjacent to setae sc2 present. Prodorsal region smooth to setae c1, with appearance of a shield (Fig. 25); region between setae sc2–c3 and c1–d1 with broad band of oblique to transverse striations; dorsal opisthosoma posterior to setae d1–c3 smooth, with appearance of distinct pygidial shield (Fig. 25). Dorsal setae similar to that of female, except smaller, and setae c1, c3 much smaller. Setal measurements: v2 2–3, sc1 3–4, sc2 63–70, c 1 13–19, c 3 20–22, d1 3–5, d3 3–4, e1 3 –4, e 3 28 –30, f 2 26–29, f 3 22–28, h 1 17–20, h2 45–50.

Gnathosoma . Palps similar to those of female. Setae d on second (distal) segment 7–8 long and eupathidia ul ′ 3, ul ′′ 1. Ventral infracapitulum setae m 8–9; distance between setae m–m 15.

Venter. Cuticle covered with fine, mostly transverse striae. Coxal, genital and anal setae fine. Setal lengths: 1a 75–85, 1b 5–6, 1c 9–10, 2b 12–15, 2c 15–17, 3a 5–7, 3b 8–10, 4a 40–50, 4b 8–10, ag 6–7, g1 4–5, ps2 5–6, ps3 4–5. Setae g2 absent.

Legs ( Fig. 24 ). Setation (from coxae to tarsi): I 2–1 –4–3–5–8(1), II 2–1 –4–3–5–8(1), III 1–2 –2–1–3–5, IV 1 – 0–1–0–3–3. Leg chaetotaxy similar to that of female, except trochanter IV nude; tarsi I–II each with one solenidion ω” 3–4 (for both tarsi I–II) and two eupathidia pζ′–pζ” (5, 5; 4–5, 5 respectively). Detail of the pattern of additions of leg setae in Table 1.

Protonymph (n = 3) ( Fig. 26 ): Body size measurements: distance between setae v2 –h1 205–210, sc2–sc2 115–125; other measurements: v2–v 2 20–25, sc1–sc1 60–65, c1–c 1 27–30, c3–c3 140–150, d1–d 1 20–25, d3–d3 98–105, e1– e 1 15–18, e3–e3 75–78, f2–f2 65–70, f3–f3 50–55, h1–h 1 17–20, h2–h2 32–35.

Dorsum. Anterior margin of prodorsum with single pair of short central lobes forming a short notch; rounded lateral body projections anterior and adjacent to setae sc2 present. Prodorsal region smooth to setae c1; region between setae sc2–c3 with few transverse striations; dorsum posterior to setae d1–c3 smooth; dorsal setae similar to that of female, except much smaller. Setal measurements: v2 2–3, sc1 3, sc2 46–54, c 1 5–10, c 3 15–21, d1 2–3, d3 3, e1 2 –3, e 3 22 –24, f 2 18–22, f 3 17–22, h 1 13–16, h2 32–35.

Gnathosoma . Palps similar to those of female. Setae d on second (distal) segment 6–7 and eupathidia ul ′ 2–3, ul ′′ 1. Ventral infracapitulum setae m 6–7; distance between setae m–m 12–13.

Venter. Cuticle covered with fine and mostly transverse striae. Coxal, genital and anal setae fine. Setal measurements: 1a 55–80, 1b 5–7, 1c 6–7, 2c 8–11, 3a 5–7, 3b 8–10, ag 4–6, ps2 3–4, ps3 4–5. Setae 2b, 4a, 4b, g1 and g2 absent.

Legs ( Fig. 26 ). Setation (from coxae to tarsi): I 2 –0–3–1–5–6(1), II 1 –0–3–1–5–6(1), III 1 –0–2–0–3–3, IV 0–0–1–0–3–3. Tarsi I–II each with one solenidion ω” (4 for tarsi I and 4–5 for tarsi II) and two eupathidia pζ′–pζ” (4–5, 5; 4, 4–5 respectively). Detail of the pattern of additions of leg setae in Table 1.

Larva (n = 1) ( Fig. 27 ): Body size measurements: distance between setae v2 –h1 170, sc2–sc2 98; other measurements: v2–v2 13, sc1–sc1 53, c1–c1 25, c3–c3 115, d1–d1 18, d3–d3 78, e1– e1 13, e3–e3 73, f2–f2 63, f3–f3 48, h1–h1 13, h2–h2 30.

Dorsum. Anterior margin of prodorsum smoothly rounded without lobes or projections. Prodorsal region with colliculate integument anteromedially, with region of smooth integument just anterior to setae c1; region between setae sc2–c3 with broad band of oblique and transverse striations; dorsum between d1–d1 and e1–e1 smooth; dorsum posterior to setae e1–d3 with colliculate integument. Setae v2, sc1, c1, d1, d3, e1 minute; other dorsal setae similar to those of female except much smaller. Setal measurements: v2 1, sc1 2, sc2 30, c1 2, c3 17, d1 3, d3 2, e1 2, e3 20, f2 18, f3 18, h1 11, h2 35.

Gnathosoma . Palps similar to those of female. Seta d on second (distal) segment 5 long and eupathidia ul ′ 2, ul ′′ 1. Setae m absent.

Venter. Cuticle covered with fine and mostly transverse striae. Coxal, genital and anal setae fine. Setal measurements: 1a 35, 1b 6, 3a 6, ps2 3, ps3 4. Setae 1c, 2b, 2c, 3b, 4a, 4b, ag, g1 and g2 absent.

Legs ( Fig. 27 ). Setation (from coxae to tarsi): I 2 –0–3–1–5–6(1), II 0–0–3–1–5–6(1), III 0–0–2–0–3–3. Tarsi I–II each with one solenidion ω” (3 for tarsi I and 4 for tarsi II) and two eupathidia pζ′–pζ” (5, 5; 4, 4 respectively). Cuticle of all legs covered with colliculate sculpturing. Detail of the pattern of additions of leg setae in Table 1.

Type material. Holotype: adult female collected on an unidentified plant of the family Sapindaceae , from Cotriguaçu , Mato Grosso, Brazil, (9°51’S, 58°25’W), 16 October 2014, coll. J.M. Rezende (DZSJRP). Paratypes: nine females, three deutonymphs, three protonymphs and one larva, same data as the holotype ( DZSJRP, NMNH) .

Etymology. This species is named in honor of Dr Elliot W. Kitajima, of the University of S„o Paulo, ESALQ- USP, Piracicaba, SP, for his dedication to the study of mites in the family Tenuipalpidae , including their plant and disease associations.

Differential diagnosis. This new species resembles T. protium sp. nov. (herein described) as explained above in the Differential diagnosis for that species. It also resembles T. caudatus and T. erbei Kane, Castro & Ochoa by sharing the presence of prominent dorsal crests on the opisthosoma (transverse between setae c1–c1 and d1–d1, and longitudinal between setae e1–e1) but differs from these two species by having a smaller, less developed, posterior crest between setae e1–e1. In addition, T. kitajimai differs from T. caudatus in the shape and size of the opisthosomal setae d1, which are minute to short (5–7) in kitajimai versus narrowly obovate to oblanceolate (52–57 long) in caudatus , and most dorsal setae are obovate to oblanceolate in kitajimai versus narrowly lanceolate in erbei .

Ontogeny. The ontogenetic changes in the idiosomal and leg setae are the same for both new species ( Table 1). The pattern of additions is also similar to that described for T. spinosaurus Castro, Feres & Ochoa , another species of T. sensu stricto group ( Castro et al. 2016b). Coxal setae 1c, 2c and 3b are added in the protonymph and 2b and 4b are added in the deutonymph. The coxal setae 4b are inserted in an unusual position, appearing to be mesal to coxal region IV, and close to setae 4a. This character state is also found in T. spinosaurus and T. boyani De Leon.

Seta v′ on trochanters I, II and III is expressed in the deutonymph and v′ is added to trochanters IV in the adult (only female known); seta l′ on trochanter III appears in the deutonymph (although it more commonly appears in protonymph (Lindquist 1985)). This same pattern of expression was observed for T. spinosaurus ( Castro et al. 2016b) .

Seta l′ is added to femora I and II in deutonymph. Setae l′ is present on genua I and II of the larvae and setae d and l” are added to genua I and II of the deutonymph. As is common in the family, setae l′ are added to genu III in the deutonymph ( Lindquist 1985); while genua IV remain nude. This pattern of expression is also found in the T. sensu lato group ( Castro et al. 2015b), while in other species of the lato group the setae l′ and l” are suppressed ( Castro et al. 2017).

The patterns of additions to the tarsi are quite varied within the family Tenuipalpidae , with variation present even within a single genus ( Welbourn et al. 2017). Here, the pairs of tectal setae are added to tarsus I, II and III in the deutonymph and to tarsus IV in the adult, which is delayed one stage from the common pattern seen in the entire superfamily Tetranychoidea. This pattern of delayed additions is also seen in closely related taxa such as T. sarcophilus Welbourn & Beard ; whereas other related taxa such as genera Acaricis and Prolixus share the standard superfamily pattern.

The ventral chaetotaxy changes match the standard pattern for the superfamily ( Lindquist, 1985), as follows: ag setae appear in protonymph; g1 and 4a in deutonymph; g2 setae are added in adult. Further information and discussion about the pattern of additions of leg and idiosomal setae in Tenuipalpus and related genera can be found in Castro et al. (2015b) and Welbourn et al. (2017).

Figures

FIGURE 15. Tenuipalpus kitajimai sp. nov. (Female): view of dorsum.

FIGURE 16. Tenuipalpus kitajimai sp. nov. (Female): a. dorsal view; b. lateral view.

FIGURE 17. Tenuipalpus kitajimai sp. nov. (Female): a. lateral view of dorsal crest; b. view of microplate.

FIGURE 19. Tenuipalpus kitajimai sp. nov. (Female): view of venter.

FIGURE 20. Tenuipalpus kitajimai sp. nov. (Female): genito-ventral and anal shields.

FIGURE 23. Tenuipalpus kitajimai sp. nov. (Female): a. leg I; b. leg II; c. leg III; d. leg IV. (Right legs).

FIGURE 24. Tenuipalpus kitajimai sp. nov. (Deutonymph): dorsum, with detail of legs (unguinal setae u′–u” on tarsus I and II are not included in the drawing).

FIGURE 26. Tenuipalpus kitajimai sp. nov. (Protonymph): dorsum, with detail of legs (unguinal setae u′–u” on tarsus I and II are not included in the drawing).

FIGURE 27. Tenuipalpus kitajimai sp. nov. (Larva): dorsum, with detail of legs (unguinal setae u′–u” on tarsus I and II are not included in the drawing).