Ameronothrus lineatus ( Thorell, 1871 )

Ermilov, Sergey G., Stary, Josef & Block, William, 2012, Morphology of juvenile instars of Ameronothridae (Acari: Oribatida), Zootaxa 3224 (1), pp. 1-40: 10-24

publication ID

http://doi.org/ 10.11646/zootaxa.3224.1.1

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http://treatment.plazi.org/id/03938782-9D79-FF88-E782-E3E5FE37FC15

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Felipe

scientific name

Ameronothrus lineatus ( Thorell, 1871 )
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Ameronothrus lineatus ( Thorell, 1871)  

( Figs. 42–78 View FIGURES 42–43 View FIGURES 44–47 View FIGURES 48–49 View FIGURES 50–65 View FIGURES 66–71 View FIGURES 72–78 )

Dimensions. Length: larva 315–332 (n=2), protonymph 381–448 (n=3), deutonymph 498–531 (n=4), tritonymph 614–680 (n=5). Width: larva 182 (n=2), protonymph 215–249 (n=3), deutonymph 265–315 (n=4), tritonymph 381–431 (n=5).

Integument. General body cuticle weakly sclerotized, colorless to yellowish and yellow-brownish. Legs and gnathosoma sometimes more sclerotized, brownish in nymphs. Cuticle of prodorsum with one pair of diagonal folds in mid-lateral region. A horizontal folds between the diagonal folds are presented in nymphs. Cuticle of proximolateral region of prodorsum and of gastronotic, anogenital and sternal regions folded. Cuticle of lateral parts of epimeres smooth. Prodorsum proximally with three porose sclerites, medial larger than lateral pair; gastronotic region without sclerites.

Prodorsum ( Figs. 42 View FIGURES 42–43 , 48–54 View FIGURES 48–49 View FIGURES 50–65 ). Relatively short, about 2/3 length of gastronotic region in lateral view. Rostrum broadly rounded in dorsal view. All prodorsal setae set on small tubercles. Rostral seta long, setiform, smooth. Lamellar and interlamellar setae spiniform, smooth or with one cilium. Exobothridial seta short, spiniform, smooth. Sensillus longer than diameter of bothridium, with developed stalk and oval, slightly barbed head. Relative length of prodorsal setae on all juvenile instars: ro> ss> in> le> ex. Prodorsal setae measurements of juvenile instars compared in Table 4.

Gastronotic region ( Figs. 42 View FIGURES 42–43 , 48–49 View FIGURES 48–49 , 55–56 View FIGURES 50–65 ). Rounded posteriorly. Larva with 12 pairs and nymphs with 15 pairs of gastronotic setae. All setae set on small tubercles, approximately similar in length (only h 3 short in larva) spiniform, smooth or with one cilium. Cupules ia and im and ip not evident among folds of gastronotic region. Opisthonotal gland opening poorly visible.

See Table 1 for explanations.

Anogenital region ( Figs. 43 View FIGURES 42–43 , 57–60 View FIGURES 50–65 , 66–68 View FIGURES 66–71 ). Ontogenetic formulae (larva to tritonymph, respectively): genital 0–1–3–5, aggenital 0–0–1–1, adanal 0–0–3–3, anal 0–0–0–2. All setae weakly spiniform (only genital setae with thin tips), smooth. Cupules ih, ips and iad appearing in normal ontogenetic pattern.

Epimeral region ( Figs. 43 View FIGURES 42–43 , 61 View FIGURES 50–65 , 69–71 View FIGURES 66–71 ). Setal formulae for epimeres: larva 3–1–2 (third seta of first epimere forms protective scale over respective Claparède’s organ); protonymph 3–1–2–1; deutonymph and tritonymph 3–1–2–2. All setae short, spiniform and smooth.

Gnathosoma ( Figs. 72–74 View FIGURES 72–78 ). All hypostomal setae (h, m, a) setiform and barbed; a and h longer than m. Lateral lips with 2 pairs thickened, barbed adoral setae (or 1, or 2). Palp setal formula 0–2–1–3–9+1ω. Palpal solenidion ω and eupathidium acm not forming double horn. Cheliceral setae setiform, barbed; cha longer than chb.

Legs ( Figs. 44–47 View FIGURES 44–47 , 62–65 View FIGURES 50–65 , 72–78 View FIGURES 72–78 ). Ontogeny of leg setae and solenidia given in Tables 5 and 6. Leg IV of protonymph with formula 0–0–0–0–7. Setae smooth. Seta u thick, with numerous, small barbs in basal part and setiform, smooth in medio-distal part. Setae of pairs u, a, p, it and tc (sometimes also ft) with expanded, oval or rounded tip. Tibiae and genua with coupled solenidion and seta d. Famulus short, spiniform, inserted anterior to both solenidia. Solenidion φ 1 on tibia I long, setiform; other solenidia of medium size or short, weakly thickened, rod-like, blunt-ended.

See Table 3 for explanations; d σ and d φ — solenidion and seta coupled.

Halozetes crozetensis ( Richters, 1907)   1

( Figs. 79–117 View FIGURES 79–81 View FIGURES 82–85 View FIGURES 86–87 View FIGURES 88–107 View FIGURES 108–111 View FIGURES 112–117 )

Dimensions. Length: larva 298–332 (n=5), protonymph 381–398 (n=3), deutonymph 498–564 (n=3). Width: larva 132–149 (n=5), protonymph 199–215 (n=3), deutonymph 315–332 (n=3).

Integument. General body cuticle weakly sclerotized, colourless to yellowish and yellow-brownish. Legs and genital valves more sclerotized, brownish. Granular cerotegument covers body and legs in all juvenile instars; granules hemispherical, small (diameter up to 2 µm). Cuticle of prodorsum with several folds dorsally; one pair of parallel folds in mid-lateral part. Cuticle of proximolateral region of prodorsum and of gastronotic, anogenital and sternal regions folded. Cuticle of lateral parts of epimeres smooth. Gastronotic porose sclerites absent. Indistinct foveolae present postero-laterally in gastronotic and anogenital regions.

Prodorsum ( Figs. 79, 81 View FIGURES 79–81 , 86–94 View FIGURES 86–87 View FIGURES 88–107 ). Relatively short, about half length of gastronotic region in lateral view. Rostrum broadly rounded in dorsal view. All prodorsal setae set on small tubercles. Rostral and lamellar setae weakly thickened, heavily barbed. Interlamellar seta longest on prodorsum, thickened, with strong barbs. Exobothridial seta shortest on prodorsum, spiniform, smooth or with one barb. Sensillus longer than diameter of bothridium, with developed stalk and oval head; latter smooth or with indistinct granules. Relative length of prodorsal setae on all juvenile instars: in> ss ≈ ro> le ≈ ex. Measurements of prodorsal setae of juvenile instars compared in Table 7.

Gastronotic region ( Figs. 79, 81 View FIGURES 79–81 , 86–87 View FIGURES 86–87 , 95–99 View FIGURES 88–107 ). Rounded posteriorly. Larva with 12 pairs and nymphs with 15 pairs of gastronotic setae. All setae set on small tubercles. Setae h 1, h 2 in larva and h 1, h 2, h 3 in nymphs longer than others, heavily barbed; others setae short, thickened, with strong barbs. Cupules ia and im not evident among folds of gastronotic region; ip and opisthonotal gland opening poorly visible.

Anogenital region ( Figs. 80 View FIGURES 79–81 , 100–103 View FIGURES 88–107 , 108–109 View FIGURES 108–111 ). Ontogenetic formulae (larva to deutonymph, respectively): genital 0–1–3, aggenital 0–0–1, adanal 0–0–3, anal 0–0–0. All setae short, spiniform, smooth. Cupules ih, ips and iad poorly visible (often cupules well visible only when located near paraproctal valves), appearing in normal ontogenetic pattern.

Epimeral region ( Figs. 80 View FIGURES 79–81 , 104 View FIGURES 88–107 , 110–111 View FIGURES 108–111 ). Setal formulae for epimeres: larva 3–1–2 (third seta of first epimere forms protective scale over respective Claparède’s organ); protonymph 3–1–2–1; deutonymph 3–1–2–2 All setae similar in length, spiniform, smooth.

See Table 1 for explanations.

Gnathosoma ( Figs. 112–114 View FIGURES 112–117 ). All hypostomal setae (h, m, a) setiform; a and h slightly barbed, longer than smooth m. Lateral lips with 2 pairs thickened, barbed adoral setae (or 1, or 2). Palp setal formula 0–2–1–3–9+1ω. Palpal solenidion ω and eupathidium acm connected, forming double horn. Cheliceral setae similar in length; cha thickened, heavily barbed, chb little shorter, setiform, barbed.

Legs ( Figs. 82–85 View FIGURES 82–85 , 115–117 View FIGURES 112–117 ). Ontogeny of leg setae and solenidia given in Tables 8 and 9. Leg IV of protonymph with formula 0–0–0–0–7. Many setae (except on tarsi) thickened, with few, strong barbs. Seta u thick, barbed in basal part and setiform, smooth in medio-distal part. Setal pairs u, a, p, it and tc with expanded, oval or rounded tips. Famulus short, spiniform. Solenidion φ 1 on tibia I long, setiform; other solenidia of medium size or short, weakly thickened, rod-like, blunt-ended.

See Table 3 for explanations.