Acalvolia americana Fan, George & Kumarasinghe, 2010, sp. nov.
Creators: name: Fan, Qing-Hai
name: George, Sherly
name: Kumarasinghe, Lalith
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Arachnida
Astigmata
Winterschmidtiidae
Acalvolia
Acalvolia americana

description: Acalvolia americana sp. nov.
(Figs. 1–14, Plates 1–3)
Material examined. Five slides stored in the PANZ (Plant Health & Environment Laboratory, Auckland, New Zealand) insect reference collection were studied. SLIDE 1: holotype female, a paratype female, intercepted on orange (Citrus sinensis) from the United States of America (USA), 18 May 2006 (Accession No. 09/2006/2528); SLIDE 2: a paratype male, a paratype tritonymph and a damaged protonymph, intercepted on orange from USA, 7 Apr 2003 (Accession No. 09/2003/1734); SLIDE 3: two paratype females and a paratype male, intercepted on orange from USA, 6 Apr 2009 (Accession No. 09/2009/1785); SLIDE 4: a paratype female, intercepted on orange from USA, 18 May 2005 (Accession No. 09/2005/2986); SLIDE 5: a paratype female, intercepted on orange from USA, 31 Mar. 2010 (Accession No. 09/2010/1820).
The slide with holotype female and a paratype female will be deposited in NZAC (New Zealand Arthropod Collection). Other slides are retained in PANZ.
Diagnosis. FEMALE. Supracoxal setae scx smooth, without barbs, tapering from base to tip; ratio sci: sce= 2.5(2.5–2.8); setae c1, d1 and e1 reaching or overlapping bases of setae in next row; coxal plates II large, extending far beyond apex of apodeme II, posterior margin concave; spermathecal duct a cylindrical tube, widening as it connects subterminally to spermathecal sac; sclerotised base of spermathecal sac blind ended, U-shaped, a pair of bell-shaped sclerites of oviducts situated at the end of spermathecal sac.
MALE. Supracoxal setae, ratio sci: sce, comparative length and distances of setae c1, d1 and e1 as in female; aedeagus medially curved, gradually tapering from base to tip; ventro-terminal sucker of tarsi I and II large, extending to bases of wa.
Description. FEMALE (n= 5; Figs 1–5, Plate 1).
Idiosomal length 465 (380–465), width at level between coxae II and III 297 (225–297); cuticle without obvious striation. Chelicerae (Fig 3 A) robustly chelate, 78 (68–78), movable digit 28 (25–30), cheliceral seta cha conical, spiniform, 4 (3–4); subcapitulum (Fig 3 B) bearing setae m, 23 (22–25); palpal supracoxal seta elcp absent; dorsal palptibial seta filiform, 22 (21–27), lateral palptibial seta filiform, 14 (12–15), dorsal palptarsal seta filiform, 9 (7–10), terminal palptarsal solenidion tiny, 4 (3–4).
Dorsum (Fig 1). Prodorsal shield nearly trapezoidal, faintly and evenly punctate, 85 (76–88) long, width at anterior and posterior margins 63 (50–63) and 83 (83–94), respectively; lateral margins of anterior half slightly concave, posterior margin slightly convex. Supracoxal sclerite elongate, duct of supracoxal gland prominent and opens at midway of supracoxal sclerite; Grandjean’s organ (Fig 3 C) smooth and short, finger-shaped, 6 (5–6); supracoxal setae scx (Fig 3 C) smooth, setiform, tapering from base to tip, 27 (26–27). Opisthonotal gland openings gla closer to e2 than to d2. Opisthosoma with three pairs of tiny tubercles, first pair posteriad of h1, second pair at level of rear end of anus and third pair posteriad of ps1. External vertical setae ve represented by alveoli, distance between them 67 (64–76). All other dorsal idiosomal setae smooth; vi, sci, c1, c2, d1, e1, e2 and h1 subequal; sce obviously longer than sci, ratios: sce: sci= 2.5 (2.5–2.8), sci–sci: sci–sce= 1.1 (1.1–1.7); setal lengths: vi 78 (75– 78), sci 78 (71–81), sce 193 (176–196); distances: vi– vi 10, vi–ve 48 (42–49), sci–sci 38 (32–47), sci–sce 34 (27– 34). Hysterosomal setae, d2 about 1.4 (1–1.4)× length of c1; lengths: c1 75 (75–100), c2 84 (77–86), cp 135 (125– 135), c3 70 (56–7 (73–100), d2 103 (100–103), e1 95 (81–103), e2 90 (78–96), f2 68 (61–68), h1 81 (80–105), h2 228 (196–260), h3 absent; distances: c1–c1 64 (49–64), c1–d1 65 (50–71), d1–d1 63 (48–64), d2–gla 85 (62–85), d1– e 1 75 (63–75), e1– e 1 75 (64–83).
Venter (Fig 2). Coxal apodemes I joined at midline, forming a prosternal apodeme directed posteromedially; coxal plate I posteriorly extending beyond apex of prosternal apodeme and widely expanded laterally; coxal apodemes II directed posteromedially, plates large, extending far beyond apex of apodeme II, posterior margin concave; sejugal apodeme very faint, a simple suture; epigynal sclerite thickened, just anterior to genital opening; apodemes III and IV directed anteriomedially, apodeme IV medially connected with posterior sclerite of coxa III. Ventral setae 1a inserted posterolaterad of coxal plate I, 3a laterad of genital opening, g posterior to genital papillae, 4a posterior to genital opening; lengths: 1a = 43 (40–44), 3a= 33 (25–33), 4a= 30 (28–30), g= 30 (23– 30). Genital opening inverted V-shaped, situated centrally between coxae III–IV. Anal opening far posterior to genital opening, about as long as genital opening, surrounded by 3 pairs of pseudanal setae, ps1 3.9 (3.9–4.2)× as long as ps2 and 4.3 (4.2–5.3)× as long as ps3, lengths: ps3= 50 (35–50), ps2= 55 (44–55), ps1= 215 (184–220). Copulatory opening posterior to anus (Fig 3 D); spermathecal duct a cylindrical tube, widening as it reaches spermathecal sac; sclerotised base of spermathecal sac narrowly U-shaped, a pair of bell-shaped sclerites of oviducts situated at end of spermathecal sac, 4 (4–5).
Leg lengths (I–IV): 205 (172–208), 200 (165–200), 212 (182–230) and 250 (205–257); all setae on trochanters, femora, genua, tibiae and basal two thirds of tarsi smooth and attenuate.
Leg I (Fig 4 A). Trochanter I with 8–12 minute teeth on anteromedial edge; femur I 45 (37–51), vF filiform, slightly longer (50 (48–54)) than femur I; genu I 35 (28–37), solenidia σ' 38 (32–38), σ" 58 (56–66); σ": σ'= 1.5 (1.5–2.1), setae cG and mG subequal, 35 (33–35) and 33 (30–37), respectively; tibia I 35 (30–35), φ 95 (95–98), gT and hT subequal, 28 (23–29) and 29 (26–32), respectively; tarsus I (excluding pretarsus, same as below) 69 (64– 72) long, about 4.3 (4.1–5.1)× as long as its basal width (16 (14–16)), ω1 (Fig 5 A) parallel sided and gradually tapered at its apex, 19 (16–19) long, ε 5 (4–5), ω2 6.5 (6–6.5), ω3 28 (28–33), setae wa 47 (40–47), ra 27 (25–30), la 25 (20–30), d 21 (21–25), e 6 (5–6), f 8 (8–10); ventro-terminal spine s 5 (5–6), u basally merged with p, v basally merged with q, u = v = 3 (3–4), p = q = 5 (4–5); membranous empodium 13 (12–18), claw 6 (5–6).
Leg II (Fig 4 B). As in trochanter I, trochanter II also has 8–12 minute teeth on anteromedial edge; femur II 45 (41–49), vF 55 (49–56); genu II 33 (28–34), σ 16 (16–22), cG 22 (20–26), mG 27 (24–30); tibia II 35 (28–35), φ whip-like, 126 (105–127), gT 27 (23–32), hT 25 (20–25); tarsus II 67 (61–71) long, about 4.5 (4.0–5.1)× as long as its basal width (15 (14–17)); ω parallel sided and gradually tapered at its apex, 19 (19–20) long, wa 44 (37–44), ra 28 (24–32), la 25 (23–27), d 33 (29–35), e 5 (4–5), f 7 (6–8), s 5 (4–5), u basally merged with p, v basally merged with q, u = v = 3 (3–4), p = q = 5 (4–5), empodium 13 (11–16), claw 6 (5–6).
Leg III (Fig 4 C). Femur III 42 (35–44); genu III 31 (26–32), σ 10, nG absent; tibia III 33 (28–37), φ whiplike, 117 (96–117), kT 36 (28–36); tarsus III 82 (73–82) long, 13 (12–15) wide at base, ratio length: width= 6.3 (5.4–6.3), w 39 (30–39), r 19 (15–18), d 48 (37–48), e 3 (3–4), f 4 (4–6), s 5 (4–5), u basally merged with p, v basally merged with q, u = v = 2 (2–3), p = q = 4, empodium 14 (12–16), claw 6 (5–6).
Leg IV (Fig 4 D). Femur IV 47 (41–50), wF absent; genu IV 35 (30–39); tibia IV 36 (31–37), φ whip-like, 114 (98–117), kT 38 (34–40); tarsus IV 97 (91–198) long, 15 (13–17) wide at segment base, ratio length: width= 6.5 (5.8–7.4), w 33 (30–37) long, r 20 (18–22) long, d 44 (44–51), e and f absent, s 5 (5–6), u basally merged with p, v basally merged with q, u = v = 2, p = q = 4 (4–5), empodium 15 (12–16), claw 6 (6–6.5).
MALE (n= 2; Figs. 6–10, Plate 2)
Idiosomal length 350 (326–350), width at level between coxae II and III 205; cuticle without obvious striation. Chelicerae (Fig 8 A) robustly chelate, 75 (64–75), movable digit 28 (27–28), cheliceral seta cha conical, spiniform, 4; subcapitulum (Fig 8 B) bearing a pair of subcapitular setae m, 23; palpal supracoxal seta elcp normally at dorsolateral sides absent; dorsal palptibial seta filiform, 15 (12–15) long, lateral palptibial seta filiform, 14 (13–14), dorsal palptarsal seta filiform, 11, terminal palptarsal solenidion tiny, 4.
Dorsum (Fig 6). Prodorsal shield as in female, faintly punctate, with posterior half wider than anterior half, 75 (75–76) long, width at anterior and posterior margins 59 and 86, respectively; Supracoxal sclerite elongate, duct of supracoxal gland prominent and opens at midway of supracoxal sclerite; Grandjean’s organ (Fig 8 C) smooth and short, finger-shaped, 4 long; supracoxal setae scx smooth, setiform, tapering from base to tip, 28 (27–28). Opisthonotal gland openings gla closer to e2 than to d2. One pair of tiny tubercles posteriad of h1. External vertical setae ve represented by alveoli, distance between them 72. All other dorsal idiosomal setae filiform, without barbs; sce about 2.5 (2.5–2.7)× as long as sci; distance sci–sci 1.5× as wide as sci–sce; lengths: vi 66 (66–69), sci 72 (67– 72), sce 181 (181–182); distances: vi– vi 9, sci–sci 39 (37–39), sci–sce 25. Hysterosomal setae, d2 about 1.2× length of c1; lengths: c1 75 (69–75), c2 74 (74–76), cp 117 (110–117), c3 54 (44–54), d1 (69), d2 89 (81–89), e1 80 (80–81), e2 84 (78–84), f2 67 (67–71), h1 78 (74–78), h2 235 (232–235), h3 absent; distances: c1–c1 41 (41–44), c1–d1 54, d1–d1 45 (30–45), d2–gla 55 (54–55), d1– e 1 40 (40–44), e1– e 1 57 (44–57).
PLATE 1. Acalvolia americana sp. nov. (female). A, prodorsal shield; B, supracoxal setae and ducts of supracoxal gland; C, coxae I and II; D, copulatory opening and spermatheca.
Venter (Figs 7 and 8). Coxal apodemes I joined at midline as in female; coxal plates II larger than those in female, their posterior edges rounded, nearly reaching sejugal suture, sejugal apodeme represented by a simple suture; epigynal sclerite thickened, inverted U-shaped, its anterior rim contiguous with medial part of apodemes IV which is medially fused together. Ventral setae 3a and 4a absent, genital setae g anterior to genital papillae; lengths: 1a = 32 (30–32), g= 30 (27–30). Genital opening situated between coxae IV, aedeagus (Figs 8 D and 8E) gradually tapering from base to tip and medially curved. Anal opening surrounded by 3 pairs of pseudanal setae, about 1.3× as long as distance between anterior rim of anus and posterior end of basal region of aedeagus: pseudanal setae ps1 4.2× as long as ps2 and 4.0 (4.0–4.6)× as long as ps3, lengths: ps3= 43 (37–43), ps2= 41 (41–42), ps1= 172.
Legs I and II slightly thicker than legs III and IV, tarsi I and II obviously shorter than those in female, each bearing a subterminal ventral sucker; lengths of legs I–IV: 165 (165–167), 165 (165–171), 202 (181–202) and 210 (198–210); all setae on trochanters, femora, genua and tibiae smooth and attenuate.
Leg I (Figs 9 A and 10A, B). Trochanter I with 8–12 minute teeth on anteromedial edge; femur I 42 (42–44), vF filiform, 53 (47–53); genu I 30, solenidia σ' 37 (34–37), σ" 55 (55–56); σ": σ'= 1.5 (1.5–1.6), setae cG 35 (34–35), mG 31 (27–31); tibia I 32, φ 100 (100–102), gT 27 (25–27), hT 25 (20–25); tarsus I 45 (44–45), about 2.3 (2.3– 2.6)× as long as its basal width (20 (17–20)), ω1 parallel sided and gradually tapered at its apex, 18 (17–18) long, ε 4, ω2 8 (7–8), ω3 28 (28–32), setae wa 25 (25–30), ra 20, la 20, d 24 (22–24), e 6 (6–7), f 10; ventro-terminal sucker large, extending to base of wa, spine s indiscernible, u fully merged with p, v basally merged with q, about 4 (3.5– 4) in length; membranous empodium 15, claw 5.5 (5.5–6).
Leg II (Figs 9 B and 10C–E). Trochanter II with 8–12 minute teeth as in trochanter I; femur II 42 (42–44), vF 43 (42–43); genu II 32 (32–34), σ 22 (20–22), cG 30 (23–30), mG 19 (19–20); tibia II 32 (32–33), φ whip-like, 112 (112–124), gT 27 (23–27), hT 26 (22–26); tarsus II 43 long, about 2.5 (2.5–2.8)× as long as its basal width (17 (15–17)); ω parallel sided and gradually tapered at its apex, 17 (15–17) long, wa 26 (26–29), ra 21 (18–21), la 21 (17–21), d 37 (35–37), e 4 (4–5), f 8; ventro-terminal sucker large, extending to base of wa, spine s indiscernible, u fully merged with p and v basally merged with q, about 4 (3.5–4) in length; membranous empodium 16 (15–16), claw 5.5 (5.5–6).
Leg III (Figs 9 C and 10F, G). Femur III nude, 42 (35–42); genu III 27 (25–27), σ 10 (9–10), nG absent; tibia III 31 (30–31), φ whip-like, 119 (114–119), kT 34 (34–35); tarsus III 69 (69–72) long, 15 wide at base, ratio length: width= 4.6, w 35 (33–35), r 15 (11–15), d 45 (45–46), e 3, f 4, s 4, u fully merged with p and v with q, about 4.5 (4– 4.5) in length, empodium 14 (12–14), claw 5.5 (5.5–6).
Leg IV (9D and 10H, I). Femur IV nude, 45 (42–45); genu IV nude, 30 (23–30); tibia IV 29 (29–31), φ whiplike, 120 (120–129), kT 40 (39–40); tarsus IV 77 (72–82) long, 15 wide at segment base, ratio length: width= 5.1 (5.1–5.5), w 36 (36–40) long, r 14 (13–14) long, d 51 (44–51), e and f absent, s 4 (3–4), u fully merged with p, v with q, about 4 (3–4) in length, empodium 12 (11–12), claw 5.5 (5.5–6).
PLATE 2. Acalvolia americana sp. nov. (male). A, prodorsal shield and supracoxal setae; B, subcapitulum; C, genital area; D, tibia and tarsus of leg I; E, tibia and tarsus of leg II.
TRITONYMPH (n= 1; Figs. 11–14)
Idiosomal length 241, width at level between coxae II and III 156; cuticle without obvious striation. Chelicerae (Fig 13 A) robustly chelate, 54, movable digit 20, cheliceral seta cha conical, spiniform, 3; subcapitulum (Fig 13 B) bearing a pair of subcapitular setae m, 24; palpal supracoxal seta elcp normally at dorso-lateral sides absent; dorsal palptibial seta filiform, 18 long, lateral palptibial seta filiform, 12, dorsal palptarsal seta filiform, 7, terminal palptarsal solenidion tiny, 2.5.
Dorsum (Fig 11). Prodorsal shield indiscernible. Supracoxal setae scx smooth, setiform, tapering from base to tip, 24. Opisthonotal gland openings gla very close to e2. Opisthosomal tubercles perceptible. External vertical setae ve represented by alveoli, distance between them 63. All dorsal idiosomal setae (except ve) smooth, vi, sci, c1, c2, d1, e1, e2 and h1 subequal; sce obviously longer than sci, ratios: sce: sci= 3.1, sci–sci: sci–sce= 1.8; lengths: vi 55, sci 48, sce 147; distances: vi– vi 7, sci–sci 33, sci–sce 18. Hysterosomal setae, d2 about 1.3× length of c1; lengths: c1 50, c2 51, cp 77, c3 44 d1 58, d2 64, e1 55, e2 52, f2 34, h1 54, h2 146, h3 absent; distances: c1–c1 33, c1–d1 30, d1–d1 30, d2–gla 38, d1– e 1 34, e1– e 1 38
Venter (Figs 12 and 13 c). Coxal apodemes I joined at midline, forming a prosternal apodeme directed posteromedially; coxal apodemes II directed posteromedially, plates large, extending far beyond apex of apodeme II, posterior margin convex; epigynal sclerite absent; apodemes III and IV directed medially, apodeme IV not connected with posterior sclerite of coxa III. Ventral 3a anteriorad of genital opening, g at same level with anterior pair of genital papillae (Fig 13 C), 4a absent; lengths: 1a = 21, 3a= 29, g= 23. Genital opening a longitudinal slit, situated between coxae IV. Anal opening surrounded by 3 pairs of pseudanal setae, ps1 4.4× as long as ps2 and 4.0× as long as ps3, lengths: ps3= 35, ps2= 32, ps1= 141. Copulatory opening and spermathecal duct absent.
Legs lengths (I–IV): 130, 129, 128 and 149; all setae on trochanters, femora, genua, tibiae and basal two thirds of tarsi smooth and attenuate.
Leg I (Figs 14 A and 13D). Trochanter I with 8–12 minute teeth on anteromedial edge; femur I 31, vF filiform, longer (45) than femur I; genu I 21, solenidia σ' 23, σ" 41; σ": σ'= 1.8, setae cG 29, mG 24; tibia I 22, φ 73, gT and hT subequal, 23 and 25, respectively; tarsus I 47 long, about 3.1× as long as its basal width (15), ω1 parallel sided and tapered at its apex, 15 long, ε 3.5, ω2 6, ω3 27, setae wa 33, ra 17, la 19, d 19, e 3, f 6; ventro-terminal spine s, 4.5, u basally merged with p and v basally merged with q, about 3 long; membranous empodium 10, claw 4.5.
Leg II (Figs 14 B and 13E). Trochanter II also has 8–12 minute teeth on anteromedial edge; femur II 27, vF 41; genu II 23, σ 15, cG 21, mG 16; tibia II 23, φ whip-like, 95, gT 15 hT 24; tarsus II 43 long, about 3.3× as long as its basal width (13); ω parallel sided and gradually tapered at its apex, 18 long, wa 29 ra 16, la 16, d 18, e 3, f 6, s 4, u basally merged with p and v basally merged with q, about 3 long, empodium 11, claw 5.5.
Leg III (Fig 14 C and 13F). Femur III 25; genu III 21, σ 7, nG absent; tibia III 21, φ whip-like, 88, kT 24; tarsus III 51 long, 12 wide at base, length: width= 4.3, w 20, r 11, d 30, e 2.5, f 3, s 4, u basally merged with p and v basally merged with q, about 3.5 long, empodium 9, claw 5.
Leg IV (Fig 14 D and 13G). Femur IV 29, wF absent; genu IV 21; tibia IV 21, φ whip-like, 54, kT 19; tarsus IV 58 long, 12 wide at segment base, length: width= 4.8, w 17, r 14, d 31, e and f absent, s positioned close to midventral seta w, 3 long, u basally merged with p and v basally merged with q, u = v = 3, p = q = 2, empodium 9, claw 4.5.
EGG (n= 9; Plate 3)
Elongate-oval in shape, 136.5 (124.9–139.7) long, about 2.2 (1.9–2.2)× of width (61.3 (61.0–72.3)); shell of newly formed egg smooth; shell of fully developed egg ornamented with scattered and linear tubercles and surmounted longitudinally by a crenulated band (8.7 wide).
Distribution. USA (type locality not provided).
Biology. This mite species was collected from orange fruit, near the calyx where mites were usually seen hiding. Conidia of Cladosporium sp. were found in the pigmented guts suggesting that this mite species is a fungus feeder.
Etymology. The species name americana refers to the origin of this species in the United States of America.
Remarks. Three characters (the well-developed duct of supracoxal gland, serrations on anteromedial edges of trochanters I and II in both sexes and the subterminal attachment of spermathecal duct to the spermatheca in female) with taxonomic importance at family level, are recognized in this paper. Acalvolia americana sp. nov. and specimens of the genera Calvolia, Czenspinskia, Neocalvolia and Oulenzia in PANZ share these characters.
This species can be readily distinguished from the only known species, Acalvolia squamata (Oudemans, 1909), by the following key.
PLATE 3. Acalvolia americana sp. nov. (fully developed egg). A, surface ornamentation and half view of the longitudinal circular band of unknown substance; B, surface ornamentation and the longitudinal circular band of unknown substance.
description: Published as part of Fan, Qing-Hai, George, Sherly & Kumarasinghe, Lalith, 2010, Genus Acalvolia (Acari: Winterschmidtiidae), with the description of a new species from the USA, pp. 41-61 in Zootaxa 2719 on pages 42-60, DOI: 10.5281/zenodo.199844