Teleioliodes ghanensis Wallwork, 1963

Bayartogtokh, Badamdorj & Ermilov, Sergey G., 2018, Ontogeny of morphological traits in Teleioliodes ghanensis Wallwork, 1963, with remarks on juveniles of Neoliodidae (Acari: Oribatida), Zootaxa 4540 (1) : -

Teleioliodes ghanensis Wallwork, 1963

( Figs 1–23 )

Measurements. Total length of: larvae 398–415 (n= 3), protonymphs 448–481 (n= 3), deutonymphs 597–664 (n= 4), tritonymphs 713–929 (n= 7). Total width of: larvae 166–182 (n= 3), protonymphs 182–215 (n= 3), deutonymphs 232–265 (n= 4), tritonymphs 332–498 (n= 7).

Integument ( Figs. 1–4 , 7–13 ). Body cuticle colorless to light brownish, covered by thick layer of gel-like cerotegument, which forms polygonal depressions and polygonal ornamentation on the dorsoanterior part of prodorsum. Sternal and anogenital regions and subcapitular mentum in all instars, gastronotic region in larva, lateral parts of gastronotic regions in nymphs folded.

Prodorsum ( Figs 1, 3 , 4 ). Relatively short, about 2/5 length of gastronotic region. Rostrum broadly rounded. One pair of dorsolateral longitudinal prodorsal ridges present. Rostral, lamellar, interlamellar and exobothridial setae slightly phylliform, dilated in median part, barbed, inserted on tubercles. Bothridial setae clavate to fusiform, barbed, with stalks slightly longer than heads. Setae lengths during ontogeny are presented in Table 1.

Gastronotic region ( Figs 1–6 , 10–12 ). Triangularly rounded posteriorly, with longest setae h 1. Larvae with nine pairs of true setae (da, dm, dp, la, lm, lp, h 1, h 2, h 3), but small p 1, p 2 also present; nymphs with five pairs of setae (h 1, h 2, p 1, p 2, p 3). All gastronotic setae well or slightly phylliform, dilated distally, barbed. Larval scalp with seven setae (da, dm, dp, la, lm, lp, h 1), nymphal scalps with four setae (h 1, h 2, p 1, p 2). Cupules ia and im not visible in all instars, ih and opisthonotal gland openings distinct only in larvae and protonymphs, ip only in larvae, ips only in protonymphs. Setae lengths during ontogeny are presented in Table 1.

Gnathosoma ( Figs 13–15 ). Subcapitulum longer than wide. Subcapitular setae h phylliform, dilated in median part, slightly barbed, a and m setiform, barbed. Adoral setae or 1 dilated and truncated distally, smooth, or 2 setiform, barbed. Palps with typical setation 0–2–1–3–9 (+ω). Chelicerae with two setiform, barbed setae. Trägårdh’s organ of chelicerae elongate triangular. Gnathosoma and setae lengths during ontogeny are presented in Table 2.

Epimeral region ( Figs 2, 3 , 7–9 ). Anterior margin of ventral plate overlapping medially. Setal formulas for epimeres: larva 3–1–2 (third setae of first epimere form protective scales over respective Claparède’s organs); protonymph 3–1–2–1; deutonymph 3–1–2–3, tritonymph 3–2–2–3. Epimeral setae phylliform, dilated in median part, slightly barbed. Setae lengths during ontogeny are presented in Table 1.

Anogenital region ( Figs 2, 3 , 7–12 ). Ontogeny of genital, aggenital, adanal and anal setal formulas, larvae to tritonymphs, 0–1–4–6, 0–0–1–1, 0–3–3–3, 0–0–2–2, respectively. Adanal setae added in protonymphs, anal setae in deutonymphs. All setae phylliform, dilated in median part, slightly barbed. Cupules iad slightly visible. Setae lengths during ontogeny are presented in Table 1.

Legs ( Figs 16–23 ). Claw of each leg indistinctly barbed on dorsal side. All tibiae and femora, and trochanters III, IV with one saccule. Leg formulas: larva: I (0– 2–3–4–16) [1–1–1], II (0– 2–3–3–13) [1–1–1], III (0– 2–2–2–13) [1–1–0]; protonymph: I (0– 2–3–4–16) [1–1–2], II (0– 4–3–3–13) [1–1–1], III (1–2–2–3–13) [1–1–0], IV (0–1– 0–1–7) [0–0–0]; deutonymph: I (1–4–3–5–16) [1–2–2], II (1–4–3–4–13) [1–1–2], III (2–3–2–4–13) [1–1–0], IV (1–2–2–3–12) [0–1–0]; tritonymph: I (1–4–3–5–18) [1–2–2], II (1–5–3–5–15) [1–1–2], III (2–3–2–4–15) [1–1–0], IV (1–3–2–4–12) [0–1–0]. Homology of leg setae and solenidia as indicated in Table 3.

ONTOGENY OF MORPHOLOGICAL TRAITS IN TELEIOLIODES GHANENSIS Zootaxa 4540 (1) © 2018 Magnolia Press · 43 ONTOGENY OF MORPHOLOGICAL TRAITS IN TELEIOLIODES GHANENSIS Zootaxa 4540 (1) © 2018 Magnolia Press · 45 ONTOGENY OF MORPHOLOGICAL TRAITS IN TELEIOLIODES GHANENSIS Zootaxa 4540 (1) © 2018 Magnolia Press · 47

Ontogeny. Juvenile instars slimmer than adult, unpigmented, light brownish or flesh-colored, covered by thick layer of gel-like cerotegument partially with polygonal depressions and folds. The prodorsum is stockier in juveniles than in adult, whereas the gastronotum is stockier in nymphs than in larva. In larva, a pair of dorsolateral longitudinal ridges is weakly developed on prodorsum, which are strongly developed and arched in nymphs. In all instars, the prodorsal setae are narrowly phylliform slightly dilating medially; these setae are short in larva, but their lengths gradually increase from stage to stage, and become remarkably longer in tritonymph. The bothridial setae are clavate in larva, but fusiform in nymphs. The gastronotum of larva is narrowed in its posterior half bearing large excrescence, while the gastronotum of nymphs is clearly widened posteriorly with much smaller, subtriangular posterior excrescence. The larva has 11 pairs of gastronotic setae (including minute p 1 and p 2, which are almost invisible), whereas the nymphs have only five pairs of them (d - and l -series are lost).

Formula of epimeral setae 3– 1–2 in larva, 3–1–2– 1 in protonymph; 3–1–2– 3 in deutonymph, 3–2– 2–3 in tritonymph. The larva has only six pairs of epimeral setae (1a, 1b, 1c, 2a, 3a and 3b), and seta 4b appears in protonymph, setae 4a and 4c are added in deutonymph, whereas seta 2b is formed in tritonymph. Norton and Franklin (2018) discussed the homologies of setae 4a and 4b, and stated that the chaetotaxy notation of epimeral setae during ontogeny of oribatid mites has been inconsistently applied in the literature due to apparent incongruence in setal positions. According to their suggestions, in the majority of oribatid mites from all main groups, a single pair of setae appeared when epimere IV first forms in the protonymph, is 4b, but not 4a. They found that seta 4a is delayed one instar during the ontogeny, while 4b is unaffected, i.e. pair 4b are protonymphal, 4a are deutonymphal. Similarly, we would denote the single epimere IV pair in Teleioliodes , also protonymphal, as 4b.

The number of genital setae gradually increases from protonymph to tritonymph. A pair of genital setae along with three pairs of adanal setae are formed first in protonymph, the latter remain unchanged in the successive stages. Four pairs of genital setae appear in deutonymph, and this number increases in tritonymph up to six pairs. A pair of aggenital setae and two pairs of anal setae are formed first in deutonymph, which remain unchanged in the successive stages. The adanal segment of paraproctal origin in deutonymphs and anal segments in tritonymphs have three and two pairs of setae, respectively, which remain the same in the adult stage. The number of leg setae increases from stage to stage. As in other species of Neoliodidae , evidently most leg setae first appear in the larval instar, but the number of setae increases from protonymph to tritonymph (see Table 3).

In the original description of Teleioliodes ghanensis, Wallwork (1963) illustrated the exuvial scalps of larva and tritonymph, and according to him the seta lp on the larval exuvia was short. However, in our studied material, seta lp was long. We consider that this seta might be variable in length or Wallwork’s description was somehow erroneous.

Figures

FIGURE 1–3. Teleioliodes ghanensis Wallwork, 1963, larva: 1— dorsal view (legs not shown); 2—ventral view (gnathosoma and legs not shown); 3—lateral view (gnathosoma and legs not shown). Scale bar 50 μm.

FIGURES 4–6. Teleioliodes ghanensis Wallwork, 1963, juvenile instars: 4—dorsal view of tritonymph (legs not shown); 5—larval scalp; 6—protonymphal scalp. Scale bars 100 μm.

FIGURE 7–15. Teleioliodes ghanensis Wallwork, 1963, juvenile instars: 7—epimeral and genitoaggenital regions of protonymph; 8 —epimeral and genitoaggenital regions of deutonymph; 9 —epimeral and genitoaggenital regions of tritonymph; 10 —anoadanal region of protonymph; 11 —anoadanal region of deutonymph; 12—anoadanal region of tritonymph; 13— subcapitulum of larva, ventral view; 14—palp of larva, right, antiaxial view; 15—chelicera of larva, left, paraxial view. Scale bars 50 μm (7–12), scale bars 15 μm (13–15).

FIGURE 16–19. Teleioliodes ghanensis Wallwork, 1963, legs of larva (16–18) and protonymph (19): 16—leg I, left, ventroparaxial view; 17 —leg II, left, ventroparaxial view; 18 —leg III, without trochanter, right, paraxial view; 19—leg IV, right, paraxial view. Scale bar 45 μm (16–18), scale bar 50 μm (19).

FIGURE 20–23. Teleioliodes ghanensis Wallwork, 1963, legs of tritonymph: 20—leg I, without trochanter, left, dorsoparaxial view; 21—leg II, without tarsus and trochanter, right, dorsoparaxial view; 22— leg III, without tarsus, left, dorsoantiaxial view; 23—leg IV, right, antiaxial view. Scale bar 50 μm.