Visma pallidum, Smith & Mitchell & Molero-Baltanás, 2021

Smith, Graeme B., Mitchell, Andrew & Molero-Baltanás, Rafael, 2021, Molecular and morphological studies identify a new genus within the Heterolepismatinae (Zygentoma: Lepismatidae), Zootaxa 5030 (1), pp. 1-118 : 32-40

Visma pallidum new species

Table 3; Figs. 1 , 14 , 24 , 30 , 35 , 39 , 51–93

Type material. Holotype, QLD: Girringun National Park , Wallaman Falls lookout area, 18.59033°S 145.80634°E 591 m asl, 11 July 2013, Graeme Smith, bark spray to soft-barked eucalypt, ♀ ( HW 1.43 ) on two slides ( QM T 24677 7) . Paratype ♂ ( HW 1.50 ), same data as holotype, on two slides ( QM T246778 ). Other paratypes : ♂ ( HW 1.38 ) on two slides (K.261312) ; ♂ ( HW 1.13 ) in alcohol (K.377814) ; ♂ ( HW 1.28 ) in alcohol (K.377815) ; ♀ ( HW 1.20 ) in alcohol (K.377816) ; ♀ ( HW 1.25 ) in alcohol (K.377817) ; ♂ ( HW 1.23 ) in alcohol (K.377818) ; six ♂♂ 11 ♀♀ 19 juveniles in alcohol (K.377819) all same data as holotype. One ♂ ( HW 1.20 ) in alcohol (K.377820) ; two ♂♂ two ♀♀ five juveniles in alcohol (K.377821) all same data as holotype but from adjacent Casuarina .

Specimen used for scanning electron microscopy: ♀ same data as holotype (gbs003503 UCO) .

Other material not included in type series: QLD: Girringun National Park , lookout halfway up hill, 18.62779°S 145.87392°E 430 m asl, 12 July 2013, Graeme Smith, barkspray to soft bark eucalypt, ♀ ( HW 1.18 ) in alcohol (K.377822) .

Diagnosis. This species can easily be distinguished from other described Visma species by the presence of a gap in the lateral chaetotaxy of the frons above the base of the antennae, by its rounded, sub-rectangular scales on the femora ( Fig. 24 ) and by the absence of a macrochaeta mediad of the anterior trichobothrial areas of the mesonotum. It also differs from some other species in the lack of combs composed of two macrochaetae on the meso- and metanota, the fairly anterior position of the anterior trichobothrial area of the pronotum, the single macrochaetae of the posterior combs of the nota, the strongly curved mandibles and the largely glabrous lateral margins of the meso- and metathoracic sterna (other species with fine setae along half or more of the lateral margins). The labial palp papillae are of equal size and arranged in a single row. Urotergite X is light-coloured.

Description. Medium-sized Heterolepismatinae , thorax at mesonotum about one fifth wider than abdomen, which only tapers slightly posteriorly from about the fifth abdominal segment; appearance when live mottled grey with a very pale urotergite X, legs darkish, antennae distinctly annulated and terminal filaments almost evenly darker brown ( Fig. 1 ). Urotergite X pale due to hyaline scales and absence of cuticle pigment.

H+B up to 10.0 mm; thorax length 2.6 mm or 0.28 H+B; width up to 1.9 mm with pro- and mesonota slightly wider than the metanotum; antennae up to 7 mm in length or up to 0.75 H+B, terminal filaments up to 6.1 mm long or about 0.76 H+B ( Fig. 51 ).

Pigment pinkish brown. Flagellum of antennae annulated with very indistinct annulation of very light pigment in basal third, more distally the density of pigment increases in some annuli with the last two annuli in each repeated interval lacking pigment, the next two with very faint pigment and the basal four with stronger pigment; pedicel and scape almost without pigment. Terminal filaments with even pigmentation (not annulated) which becomes darker distally. Head with very small amount of pigment around eyes and at base of macrochaetae of peri-antennal groups only. Clypeus with strong pigment across its distal half, labrum lightly to moderately pigmented in proximal half, stronger towards outer margins. Mandible with strong blotchy pigment. Maxillary palp with strong pigment on dorsal and ventral faces of articles two, three and four, ultimate article weakly pigmented overall. Labial palp with very little pigment, just light pigmentation on the outer margin of the penultimate article and a small area of darker pigment on the outer or both the outer and inner margins and sometimes a small line distal to the row of papillae of the ultimate article. Nota without pigment. Faint pigment along outer margin of coxae; trochanter with small dark patch of pigment posteriorly; femur with obvious very dark pigment on the bulge of the posterior margin and apically on the anterior margin; tibia of all legs with very dark patch of pigment on the distal end and a lighter area on the proximal end of the outer margin; first tarsal article with dark pigment in distal half dorsally. Urotergite X not pigmented, inner processes of coxites IX with a small area of pinkish pigment along the margin adjacent to the styli. All styli moderately pigmented except apex and base. Pigment often much lighter in some individuals.

Macrochaetae smooth, generally straw-coloured, some hyaline or dark brown (e.g. on terminal filaments), apically bifurcate with truncated tips to each bifurcation ( Fig. 52 ) or pointed. Some macrochaetae on tibia, carrotshaped.

Scales on nota and urotergites quite round, generally longer than wide, those dorsally with numerous subparallel closely-spaced brown ribs that do not, or only slightly, surpass the margin of the scale ( Fig. 53 ), with only a single scale with more widely spaced ribs seen on three specimens; ventral similar but scales hyaline. Round scales found on top of head and on all nota, all urotergites and urosternites as well as the thoracic sterna. Femur and tibia with round, subrectangular scales ( Figs. 24 , 30 ). Basal tarsal article and styli IX with small triangular and subrectangular scales. Pedicel and scape with areas of round subrectangular, some almost triangular scales. Terminal filaments with lanceolate scales. Narrow triangular scales with straight distal ends present on clypeus laterally ( Fig. 54 ); medial region of clypeus appears to have only cilia. Scales on urotergite X and ventral surface hyaline allowing the light colour of the cuticle to show through.

Head wider than long ( Fig. 55 ), without distinct bushes. Scales of frons protrude over the clypeus which is somewhat folded back or at least down making it impossible to lay out the dissected head flat without tearing along the edges of the frons-clypeal suture; anterior margin of frons glabrous, laterally with a group of about 6–8 macrochaetae anterior to the antenna but then a distinct glabrous region above the antennae before two rows of macrochaetae run back from the peri-antennal groups and single line above the eye, peri-antennal groups weak, and include a long thin seta. Clypeus with short stout macrochaetae in a line along the frons-clypeal suture and longer 1+1 groups laterally; face of clypeus with small cilia only, distal lateral region with triangular scales. Labrum with numerous cilia across the surface, 1+1 stronger but very short macrochaetae laterally and eight subapical straight thin setae, the outer two of which are about twice as long as those between them. Scape and pedicel of antenna ( Fig. 56 ) each with a subapical ring of small macrochaetae and setae as well as scales on outer face. First annulus of flagellum with a ring of small setae only; subsequent annuli with a ring of small setae and some very short trichobothria; subsequent annuli with increasingly longer and stronger but still fine setae with long curly setae becoming more numerous; seventh annulus beginning to divide into two with a clear division into two annuli by the 9th interval and into four annuli by the 13th interval. Most distal surviving intervals (probably about seven eights of total length) ( Fig. 57 ) divided into repeated patterns of four annuli, the distal three with two rings of fine setae, the basal with only one, at least one rod-like basiconic sensillum present in the distal annulus.

Mandibles strongly curved ( Figs. 58, 59 ) with well-developed molar and incisor areas; a group of about fourteen strong and short or thin and longer, apically bifurcated setae distally adjacent to the pectinate molar area and a bush of about 50 macrochaetae externally. Maxilla ( Fig. 60 ) with one to three thick apically bifurcate macrochaetae externally proximal to the palp; lacinia short and wide, with three strong teeth, one set further back than the other two, followed by about seven lamellate processes and a row of eight to ten setae, galea with one stronger seta proximally but otherwise with only short fine cilia or setulae; apical article of maxillary palp ( Fig. 61 ) 3.4 times longer than wide (range 2.5–4.6) and about 1.3 times as long as the penultimate article (range 1.0–1.6), three slender branched papillae on the apical article of the palp of both sexes and no other sensilla were seen although this may be due to some shrinkage of the slide mounted material, last two articles of palp with fine setae only, three basal articles with subapical rings of thicker setae. Labium ( Fig. 62 ) wider than long, postmentum with setae in an irregular scattered line across the anterior third, prementum with transverse and oblique groups of stronger setae and with short setulae distally; apical article of labial palp, wider than long (L/ W 0.74 in alcohol, range 0.68–0.81), with five subequal papillae of the compact type arranged in a straight line (N.B. one palp of holotype with only four papillae), no other sensilla seen; covered with numerous fine short setae, those proximal and laterally longer than those distal; penultimate article without obviously stronger setae medially.

Pronotum ( Fig. 63 ) with weak setal collar of short macrochaetae as well as some stronger long macrochaetae, and some cilia; setae of lateral margins generally short with several long strong submarginal macrochaetae. Anterior trichobothrium located at 0.41 the length of the lateral margin (range 0.39–0.44) and not associated with any submarginal macrochaeta ( Fig. 64 ). One specimen (QM T246778) has an aberrant arrangement, with two anterior trichobothria on the right side, one 0.31 and the other 0.46 along the margin, neither associated with a macrochaeta. The posterior trichobothrium mediad of a submarginal macrochaeta with two or three cilia arranged around the macrochaeta ( Fig. 65 ). Posterior margin with 1+1 single macrochaetae each associated with two cilia ( Fig. 66 ) and 1–2 setulae. Mesonotum ( Figs. 67, 68 ) and metanotum ( Figs. 69–71 ) with similar lateral and posterior chaetotaxy to pronotum; both trichobothrial areas are more posterior than those of the pronotum, the anterior areas of both not associated with any macrochaetae.

Presternum fairly long, with transverse posterior row of strong apically bifurcate macrochaetae and cilia ( Fig. 72 ). All thoracic sterna with hyaline scales. Prothoracic sternum trapezoidal, the posterior margin somewhat concave (appears to be a bit deformed in holotype), wider than long (L/ W 0.83 range 0.77–0.87), most of lateral margins fringed with cilia and fine setae, postero-lateral corners with four or five macrochaetae forming dispersed comb subparallel to the margin. Mesosternum ( Figs. 73 ) trapezoidal, wider than long (L/ W 0.94 range 0.91–0.99) with 1+1 posterolateral combs each of two macrochaetae and another more robust seta on the margin, margins around combs with alternating setae and cilia but most of posterior and lateral margins are glabrous. Metasternum ( Fig. 74 ) trapezoidal with concave posterior margin, about 1.4 times wider than long (L/ W 0.73 range 0.69–0.75), with 1+1 posterolateral combs each of two macrochaetae, with two marginal setae and 1–2 cilia adjacent to each combs, remainder of margins glabrous.

Legs ( Figs. 72–75 ) progressively longer anterior to posterior with the tibia of PII being 1.15 times longer than that of PI and the tibia of PIII being 1.74 times longer than that of PI, the relative length of the basal tarsal article only slightly progressively longer, being about 43% of the total length on PI and 50% of the length on PIII. Tibia L/W ratio of legs PI 2.7 (range 2.1–3.1), PII 3.8 (range 3.2–4.7), PIII 3.8 (range 3.2–4.7); tarsi L/W ratio PI 6.3 (range 5.5–7.3), PII 8.8 (range 6.4–11.3), PIII 9.9 (range 8.4–12.9). Subcoxa of PI only with comb of five thin setae. Coxa of PI and PII with many strong macrochaetae along the external margin, becoming more numerous but shorter distally; inner margin with three macrochaetae along the margin and about six distally over the articulation, inner dorsal surface with several long thin setae near the distal articulation. Trochanter with three small macrochaetae and several longer setae. Femur ventrally with some macrochaetae along the posterior margin especially in the region of the posterior bulge through to the outer articulation with the tibia, above which is 1–2 strong macrochaetae, posterior portion of ventral surface with scatted thin setae; anterior ventral surface covered in round, subrectangular scales that lie very flat, which are difficult to discern using a light microscope, unlike triangular or lanceolate scales. Tibia also with round, subrectangular scales on external ventral half, strong carrot-shaped macrochaeta distally shorter than apical spur, a second smaller carrot-shaped macrochaeta about half to three quarters along the ventral inner margin and another macrochaeta about half way along on dorsal surface of inner margin, external margin with single strong seta about three quarters along margin, rest of ventral surface with scattered long fine setae, apical spur distinctly hooked and bearing several setae. Tibia of PIII with very thin trichobothrium-like seta about twice as long as the tibia is wide, located dorsal of a long macrochaeta (length about the same as the width of the tibia) about one quarter the way along the tibia. Tarsi of four articles, the basal tarsal article of PI shorter than remaining articles together, bearing some stronger setae apically below; second article particularly short with two long and several short setae (no trichobothrium-like seta were observed on the second articles), suture between third and fourth articles weak. Pretarsus with two long curved lateral claws and a much shorter curved medial claw. PII ( Fig. 73 ) and PIII ( Fig. 74 ) similar to PI.

Urotergite I with 2+2 combs (lacking submedial), the lateral combs each of 1–2 macrochaetae associated with two cilia, a marginal setae and 3–4 setulae; urotergites II–VII ( Fig. 75 ) with 3+3 small combs as shown in Table 3, each lateral comb associated with 1–3 cilia, 1–4 small marginal setae and 1–6 setulae, each sublateral comb probably associated with 2–3 cilia although the more anterior insertion was never seen to contain a cilium and the insertion may represent some other form of sensory structure, as well as 1–3 small marginal setae and 1–6 setulae, each submedial comb of only one macrochaeta with a cilium on each side and 1–2 setulae ( Figs. 76–78 ); urotergite VIII ( Fig. 79 ) with 2+2 combs, lacking the sublateral comb; urotergite IX without combs but with 2–4 cilia and 3–5 small fine marginal setae in each infralateral corner. Urotergite X ( Fig. 81 ) round, short (L/W about 0.4, range 0.36–0.41) in both sexes with eight or nine stronger submarginal macrochaetae along each side as well as numerous strong setae; posterior margin without glabrous region.

Urosternite I glabrous, urosternites II–IV ( Figs. 82, 83 ) with 1+1 sublateral macrochaetae each associated with a cilium and 1–4 fine marginal setae or setulae; urosternites V – VII in female and V – VIII in the male also with a pair styli, the macrochaetae being located just mediad of the base of the styli ( Figs. 84, 85 ) with a cilium and 3–6 small fine setae laterad of the stylus base, the posterior margin of urosternite VII in the female and VIII in the male protruding and slightly convex. Urosternite VIII in ♀ divided into separate coxites with 1+1 macrochaetae mediad of the stylet base and several fine setae around the margins of the inner process, each outer process with a seta, a cilium and about five fine marginal setae ( Fig. 85 ). Five pairs of styli present (on urosternites V – IX), the styli on segments V – VIII only about half the size of those on IX, with some strong apical setae .

Coxite IX of ♀ ( Fig. 86 ), the internal process acute apically, more than four times longer than the external proc- ess and 1.6 times longer than wide at its base (range 1.6–1.7), external and internal margins of internal and apex of rounded external process with several moderately strong macrochaetae. Ovipositor ( Fig. 86 ) long about 2.5 times as long as HW (range 2.3–2.6) surpassing the end of the inner process of coxite IX by about four and a half times the length of the inner process, composed of about 44 divisions (range 44–45). Distal divisions of gonapophyses ( Figs. 87, 88 ) with some short rod-like setae and some longer fine setae.

Cerci ( Figs. 89, 91 ) with six basal divisions shorter than wide then progressively longer with one ring of setae, macrochaetae, cilia and trichobothria in the third and fourth divisions, two in the fifth and sixth, then four from the eighth, as well as lanceolate scales ( Fig. 35 ). Seven or more rings per division from the 11 th, the number of these rings/annuli increasing progressively so that there are 13 in the most distal surviving division (about the 17 th). Trichobothria visible at least until the sixteenth division in the fourth and seventh most basal of 13 rings. Median dorsal appendage ( Figs. 89, 90 ) with first two divisions covered by the epiproct, the next three divisions shorter with only a single ring of long setae, next three divisions increasingly longer with two rings, with lanceolate scales present on some divisions, at least laterally, four rings per division by about the tenth increasing to ten in the most distal survive divisions (ca 16 th) these distal divisions with trichobothria on the 3 rd, 5 th and 6 th rings and large macrochaetae on the 4 th and distal rings.

Each coxite IX ( Fig. 92 ) of male with a macrochaeta mediad (and slightly posterior) of the stylus insertion, several strong macrochaetae along the inner and outer margins of the inner process and apically on the outer process; the internal process acute, about 1.1 times longer than wide at its base (range 1.05–1.16) and 3.6 times as long as the outer process (range 3.1–4.2) which is shorter than wide at its base (L/ W 0.6 range 0.55–0.63) and rounded. Styli IX long with several stronger setae distally and along the shaft, the stylus (excluding the apical macrochaetae) about twice the length of the internal process. Penis typical with numerous glandular setae apically, each set on a protuberance. Parameres short, conical ( Figs. 92, 93 ) with about 20 long thin setae.

Habitat. Bark spray to soft barked Eucalyptus and Casuarina trees. The known distribution is shown in Fig. 46 .

Etymology. Named from the Latin adjective for pale ( pallidum ) referring to the obvious pale coloured urotergite X.

Remarks. Morphologically this species is quite distinct from all other Visma species described here. It is unique in having a gap in the lateral chaetotaxy of the head, much reduced macrochaetae on the labrum, a quite different type of scale on the femora, a macrochaeta mediad of the anterior trichobothrial area of the mesonotum and its mandibles are strongly curved.

NORTHERN INLAND GROUP

Figures

FIGURE 14. Visma pallidum n. sp., slender branched papilla of apical article of maxillary palp. Scale bar: 0.01 mm.

FIGURE 39. Visma pallidum n. sp. Scales of scape and pedicel. Scale bar: 0.01 mm.

FIGURE 46. Distribution of Visma pallidum n. sp.

FIGURES 1–4. Visma pallidum n. sp. 2. Visma brigalowsum n. sp. Miriam Vale. 3. Visma aff. brigalowsum Yanga. 4. Visma tenebrosum n. sp.

FIGURES 21–26. Scales of femora. 21. Visma aff. brigalowsum. 22. Visma tenebrosum n. sp. 23. Visma bundjalung n. sp. 24. Visma pallidum n. sp. 25. Visma xanthorrhoea n. sp. 26. Visma aff. stilivarians. Scale bar: 0.01 mm.

FIGURES 27–32. Scales of tibia. 27. Visma aff. brigalowsum. 28. Visma tenebrosum n. sp. 29. Visma bundjalung n. sp. 30. Visma pallidum n. sp. 31. Visma xanthorrhoea n. sp. 32. Visma aff. stilivarians. Scale bar: 0.01 mm.

FIGURES 33–37. Scales of cerci. 33. Visma aff. brigalowsum. 34. Visma bundjalung n. sp. 35. Visma pallidum n. sp. 36. Visma xanthorrhoea n. sp. 37. Visma aff. stilivarians. Scale bar: 0.01 mm.

FIGURES 51–62. Visma pallidum n. sp. holotype ♀ 51. Habitus. 52. Smooth, apically bifurcate macrochaeta of frons. 53. Round scale of pronotum. 54 Triangular scale of clypeus. 55. Head, with clypeus and labrum. 56. Antenna, scape, pedicel and basal intervals of flagellum. 57. Idem, most distal surviving interval showing possible minute basiconic sensillum (bs B). 58. Mandible. 59. Idem, incisor and molar regions. 60. Maxilla, smaller setae omitted from palp. 61. Idem, apex of palp. 62. Labium. Scale bars = 0.1 mm unless otherwise indicated.

FIGURES 63–72. Visma pallidum n. sp. holotype ♀ 63. Pronotum, anterior and left margins. 64. Idem, anterior trichobothrial area. 65. Idem, posterior trichobothrial area. 66. Idem, posterior comb. 67. Mesonotum, left margin. 68. Idem, anterior and posterior trichobothrial areas of right side. 69. Metanotum, left margin. 70. Idem, anterior and posterior trichobothrial areas of left side. 71. Posterior comb of metanotum. 72. Presternum, prothoracic sternum and PI. Scales: 0.1 mm.

FIGURES 73–85. Visma pallidum n. sp. holotype ♀ 73. Mesothoracic sternum and PII. 74. Metathoracic sternum and PIII. 75. Urotergite IV. 76. Urotergite VII, left lateral comb. 77. Idem, left sublateral comb. 78. Idem, left submedial comb. 79. Urotergite VIII, left lateral comb. 80. Urotergite IX, right infralateral chaetotaxy. 81. Urotergite X. 82. Urosternite II. 83. Idem, left posterior comb. 84. Urosternite VII. 85. Idem, stylus. Scales: 0.1 mm.

FIGURES 86–93. Visma pallidum n. sp. holotype ♀ unless otherwise indicated by specimen number 86. Coxites VIII and IX and ovipositor. 87. Apex of anterior gonapophyses. 88. Apex of posterior gonapophyses. 89. Base of cercus and median dorsal appendage. 90. Apical division of median dorsal appendage. 91. Apical division of cercus. 92. Coxites IX, styli, parameres and penis (K.261313). 93. Enlargement of paramere. Scales: 0.1 mm.