Visma tenebrosum, 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 : 58-66

Visma tenebrosum new species

Table 6; Figs. 4 , 17 , 22 , 28 , 38 , 41 , 44 , 174–209

Type material. Holotype, QLD: Eungella National Park , Fern Gulley track, 21.17006°S 148.49909°E 713 m asl, 9 July 2013, Graeme Smith, pyrethrum spray to trunk of soft bark rainforest tree, ♀ ( HW 1.21 ) on two slides ( QM T246782 ) . Paratype ♂ ( HW 1.50 ), same data as holotype, on two slides ( QM T246783 ). Other paratypes: juvenile ♀ ( HW 0.70), same data as holotype, in alcohol (K.377808). QLD: Eungella National Park , Fern Gulley track, 21.16895°S 148.50322°E 720 m asl, 9 July 2013, Graeme Smith, pyrethrum to trunk of soft bark rainforest tree , ♂ ( HW 1.35 ) on two slides (K.261282) ; one juvenile ♀ ( HW 0.88) and one juvenile ( HW 0.65), same data as previous, in alcohol (K.377806) .

Other material not included in type series: QLD: North of Marlborough, 22.7863°S 149.8067°E 120 m asl, 8 July 2013, Graeme Smith, pyrethrum to trunk of soft bark eucalypt , ♀ ( HW 1.14 ) on two slides (K.261314) ; ♀ ( HW 1.09 ), same data as previous, on two slides (K.261315). QLD: Gurgeena Plateau drain 25.446°S 151.376°E 350 m asl, 19 January 2013, G. Monteith, bark spray to ironbark ♀ ( HW 1.38 ) on two slides (K.541537) ; ♀ ( HW 1.39 ), same data as previous, on two slides (K.261281) ; ♀ ( HW 1.33 ), same data as previous, on two slides (K.541545) ; five specimens, same data as previous, in alcohol (K.377927) .

Other material: QLD: North of Marlborough, 22.78629°S 149.80667°E 120 m asl, 8 July 2013, Graeme Smith, ♂ ( HW 1.33 ) in alcohol, bark spray to trunk of soft bark eucalypt, (K.377809) ; ♀ ( HW 1.06 ) same data as previous, in alcohol (K.377807) ; one ♂ one ♀ eight juveniles, in alcohol (K.377810).

Specimen used for scanning electron microscopy: ♀ ( HW 1.06 ), same data as K. 377809 in alcohol gbs003422 ( UCO) .

Diagnosis. This species can be distinguished from other described species of Visma in the Northern Inland Group by a combination of characters including its banded antennae (unbanded in V. capricornia n. sp.), the more anterior position of the anterior trichobothrial areas of the pronotum (0.35–0.42 along the length versus 0.43–0.50 in V. brigalowsum n. sp.), the presence of 2–4 lateral combs (rarely five) of two macrochaetae on the meso and metanota (versus 5–7 in V. capricornia n. sp., rarely 4 in V. aff. capricornia ), and the low incidence of notal scales with widely spaced ribs, common and wider in V. brigalowsum n. sp. but also only in low numbers in V. capricornia n. sp.

Description. Moderately large silverfish, thorax at pronotum about one fifth wider than abdomen which only tapers slightly posteriorly from about the fifth abdominal segment; antennae distinctly banded, the terminal filaments either completely dark or with light areas at the apex of each division, appearance when live mottled grey with dark areas of pigment visible on femora, tibiae and the basal tarsal articles ( Fig. 4 ).

Body length: H+B up to 10.5 mm (head width 1.50 mm); thorax: length 3.0 mm or on average 0.30 H+B; width up to 2.2 mm with pronotum about the same width or just slightly narrower than the mesonotum, the metanotum about the same length as but distinctly narrower than the mesonotum; antennae and terminal filaments about two thirds H+B ( Fig. 174 ).

Pigment dark brown to pinkish brown. Flagellum of antennae with distinct light brown annulated rings. In the proximal part of the flagellum only the distal half of each annulus lacks pigment, as the repeating sections start to appear first only the most distal annulus and later the two most distal annuli (of eight) lack pigment. Scape with small weak patch above proximally, pedicel sometimes with small line of pigment distally. Terminal filaments quite darkly pigmented with only a small ring containing the insertions of the dominant ring of macrochaetae on the most distal annulus of each repeating section without pigment. Specimens from Marlborough with much more pronounced light areas consisting of all the last annulus plus a bit of the base of the next annulus and the top of the previous annulus. Head with pigment around eyes along lateral margins and quite intense between the peri-antennal group and the margin especially posterior to this group. Clypeus without pigment, labrum with 1+1 small diffuse patches laterally. Mandible without obvious pigment. Maxillary palp with light pigment above and below on the distal article, penultimate article with darker pigment apically and some pigment over the dorsal and ventral faces, third article with moderate pigment above but not below, second article with faint area of pigment above. Labial palp with pigment only along lateral margins of the distal three articles. Precoxae with distinct lines of pigment on the anterior and posterior margins, coxae with pigment strong in the anterior “shoulders” diminishing posteriorly along the outer margin and absent from the inner margin; trochanter with small patch of dark pigment posteriorly; femur with small areas of dark pigment distally on the leading edge and also on the bulge on the posterior margin, as well as a faint blotchy area on the ventral face in proximal half; tibia with very dark subdistal patches on dorsal margin and a smaller faint area proximally on this margin, tibia of PIII with more pigment over most of the surface, especially dorsally; first tarsal article with dark subdistal patch dorsally. Urotergite X, processes of coxites IX and apex of parameres with quite dark pigment giving the end of the abdomen a strikingly dark appearance in alcohol. Styli IX moderately pigmented in medial half, other styli similarly pigmented, those more anterior sometimes without pigment.

Macrochaetae smooth, straw coloured to brown, occasionally hyaline, mostly apically bifurcate with truncated tips to each bifurcation. Some macrochaetae carrot-shaped.

Most major scales long and round but some of eccentric shapes ( Figs. 17 , 175 ) with numerous dark brown (or hyaline ventrally) subparallel ribs that do not surpass the margin of the scale, the vast majority with closely-spaced ribs, but some with wider (but not very wide) spacing in the antero-lateral corners of the pronotum. Round scales found on top of head, nota and all thoracic sterna and coxae, present on all urotergites and urosternites. Scales absent from labrum and tarsi; some triangular scales seen on articles two and three of maxillary palp. Clypeus with narrow triangular scales, some with serrated ends others with more rounded ends, and possibly also some lanceolate ( Fig.382 ). Triangular scales of femora ( Fig. 22 ) wider, almost subrectangular with serrated distal margin that does not have a strong emargination. Similar scales also on scapus. Triangular scales of tibia somewhat narrower but not approaching lanceolate, with either serrated or triangularly incised apices ( Fig. 28 ). Lanceolate scales present on more basal divisions of terminal filaments.

Head wider than long ( Fig. 176 ), without distinct bushes, scales protrude over glabrous anterior margin of frons, laterally with a group of 8–14 strong macrochaetae anterior to the antenna which then become thinner and shorter in two rows then further widening to three or four macrochaetae wide from the region of the peri-antennal group; the peri-antennal group sometimes separated from the marginal chaetotaxy by a short gap, each peri-antennal group with 2–5 smaller macrochaetae as well as one very long thin, trichobothrium-like sensillum and a few long cilia. The macrochaetae on the sides of the head become longer and thicker with several macrochaetae irregularly above each eye, the last macrochaeta large and associated with several cilia; no obvious gap between the lateral macrochaetae and those around the eyes. Clypeus with some macrochaetae laterally as well as setae and scales; face of clypeus with small cilia and numerous narrow triangular scales. Labrum with several macrochaetae scattered across the proximal face as well as cilia and fine setae, 3+3 long thin simple setae just before mid-length of the labrum with only setae and cilia in the next quarter, subapically with usual six straight thin setae. Scape and pedicel of antenna ( Fig. 177 ) each with a subapical ring of small macrochaetae and setae on their face, scape with triangular scales on anterior and outer face, pedicel sometimes with small triangular scales on inner 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 not increasing much in length, each with a single ring of setae and trichobothria as well as a few cilia, a thin straight seta appears in the ring from the fifth annulus of the flagellum; seventh annulus beginning to divide into two with a clear division into two annuli by the 9 th interval and division into four annuli starting by the 10th interval. Most distal surviving intervals ( Figs. 41 , 178 ) divided into repeated patterns of about 14 annuli, with six in the more basal chain and eight in the more distal, most annuli with a ring of setae but the 3rd, 6th, 8th, 10th and 12th have only cilia; rod-like basiconic sensilla were observed in the most distal annulus of each chain.

Mandibles typical for Heterolepismatinae , not strongly curved ( Figs. 179, 180 ) with well-developed molar and incisor areas; a group of about 8–14 strong and short or thin and longer, apically bifurcated setae distally adjacent to the pectinate molar area and a bush of about 80 macrochaetae externally. Maxilla ( Figs. 181, 182 ) 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 six to nine setae, galea with 1–2 stronger seta proximally but otherwise with only short fine cilia or setulae; apical article of maxillary palp 4.0 times longer than wide (range 3.30–4.53) and about 1.2 times the length of the penultimate article (range 0.95–1.38), the ultimate article probably with three slender simple branched papillae of the thin type (only two observed on the male QM T246783, one on K.261314 and possibly one on the holotype probably because in all slide mounted maxillae the last article of the palp had contracted slightly and the papillae are usually to be found in the groove resulting from contraction), and with a single sausage-shaped (?) basiconic sensillum (type C) near the apex; last two articles of palp without thicker setae, a basiconic sensillum type B was observed on a few specimens, third article with some slightly stronger setae towards the distal end as well as one small carrot-shaped macrochaeta, two basal articles with subapical rings of thicker setae. Labium ( Fig. 183 ) much wider than long, postmentum with long thin setae in an irregular scattered line across the anterior third, prementum with transverse and oblique groups of stronger setae and with short cilia and setulae distally; apical article of labial palp wider than long (L/ W 0.65, range 0.53–0.83), with five subequal papillae of the compact type arranged in a straight line, a small basiconic sensillum type C seen on one palp only of QM T246783; covered with numerous fine short setae, those proximal and laterally longer than those distal; penultimate article with only slightly stronger setae medially.

Pronotum ( Fig. 184 ) with setal collar of short to medium length macrochaetae and some small setulae and cilia; the macrochaetae much less dense in the medial region; entire lateral margins with medium to short macrochaetae and some cilia as well as several longer submarginal macrochaetae. The anterior trichobothrial area ( Fig. 185 ) well forward, located about 0.39 the distance along the lateral margin (range 0.35–0.42), the trichobothrium not associated with a macrochaeta but with a setula and a cilium. The posterior trichobothrium ( Fig. 186 ) mediad of a submarginal macrochaeta with a couple of setulae posterior to this group. Posterior margin with 1+1 single macrochaetae each associated with two cilia and a setula ( Fig. 184 ). Mesonotum ( Fig. 187 ) with similar lateral chaetotaxy to pronotum except 2–5 of the submarginal combs (in the anterior half) are composed of two macrochaetae; the anterior trichobothrial areas ( Fig. 188 ) are located about ⅔ along the margin with a macrochaeta located mediad of the short trichobothrium as well as a few setulae; the posterior trichobothrial area located about 0.85 the distance along the margin, with a very strong macrochaeta between the trichobothrium and the margin as well as a cilium and a setula; 1+1 posterior macrochaetae as in pronotum. Metanotum ( Fig. 189 ) similar to mesonotum except the trichobothrial areas even more posterior and lacking the macrochaeta mediad of the trichobothrium ( Fig. 190 ).

Presternum narrow, with transverse rows of strong apically bifurcate macrochaetae as well as some smaller setae and cilia ( Fig. 191 ). All thoracic sterna with hyaline scales. Prothoracic sternum trapezoidal, slightly wider at base as long (L/ W 0.91, range 0.87–0.93), entire lateral margins with fine setae, postero-lateral corners with 1+1 combs of three or four macrochaetae and 1–3 strong pointed marginal setae; posterior margin between the combs glabrous. Mesosternum ( Fig. 192 ) trapezoidal, wider than long (L/ W 0.91, range 0.87–0.95) with fine setae along posterior two thirds of each lateral margin, 1+1 postero-lateral combs each of one long thick marginal seta and two macrochaetae, posterior margin between combs glabrous. Metasternum ( Fig. 193 ) apically rounded, much wider than long (L/ W 0.67, range 0.65–0.69), distal half of lateral margins with fine setae, each postero-lateral corner with a comb of two submarginal macrochaetae and a strong marginal seta as well as some cilia, posterior margin between the combs glabrous.

Legs ( Figs. 44 , 191–193 ) progressively longer anterior to posterior with the tibia of PI being 0.56 times the length of PIII (range 0.51–0.61) and the tarsus of PI being 0.63 the length of PIII (range 0.61–0.67). Tibia L/W ratio of legs PI 2.6 (range 2.3–2.9), PII 3.2 (range 2.6–4.0), PIII 4.1 (range 3.8–4.4); tarsi L/W ratio PI 6.3 (range 5.2–6.7), PII 7.4 (range 6.5–8.4), PIII 9.2 (range 8.5–10.0). Precoxa of PI only with comb of four strong macrochaetae near the anterolateral corner. Coxae with many strong macrochaetae along the external margin, becoming more numerous distally; inner margin with four to six macrochaetae along the margin as well as a group of about seven setae distally over the articulation and some fine setae distally on the dorsal face. Trochanter with one macrochaeta and one strong seta as well as several other setae. Femur ventrally with some macrochaetae along the posterior margin, the line of macrochaetae extending along the face subdistally towards the articulation; anterior margin with two strong seta about ⅔ along the margin and a macrochaeta as well as a cluster of three or four strong setae closer to the distal end. Ventral face of femur with triangular scales in the anterior half and setae in the posterior half. Tibia with two macrochaetae along the dorsal margin and two strong carrot-shaped macrochaetae on the ventral margin as well as some longer setae along the face adjacent to the posterior margin; apical spur distinctly hooked and bearing several small setae; face of tibia also with setae and triangular scales. Tarsi of four articles, the basal tarsal article of PI only slightly longer than half the length of the remaining articles together, basal article of PII about equal in length to the last three articles together, bearing some stronger setae below; second and third articles of PI short with two long setae and several smaller setae but not very densely setated; second tarsal article with trichobothrium ( Fig. 44 ). Pretarsus with two long curved lateral claws and a much shorter straight medial claw. PII ( Fig. 192 ) and PIII ( Fig. 193 ) similar to PI except tibia of PIII with a trichobothrium about 1.75 times longer than the tibia is wide and four carrot-shaped macrochaetae along the posterior margin, the basal tarsal article is about as long as the distal three combined.

Urotergite I with 2+2 combs (lacking submedial), each comb of two macrochaetae associated with 1–2 small marginal setae, 2–3 setulae and two cilia. Urotergites II–VII with 3+3 small combs as shown in Table 6, each lateral comb associated with two marginal setae, 1–3 cilia, one mediad of the comb, the others anterior to and between the insertions and 1–4 setulae between the combs and the margins, each sublateral comb with two or rarely three macrochaetae, two cilia, 1–2 marginal setae and 1–3 setulae, each submedial comb with one macrochaeta, two cilia and a single setula ( Figs. 194–197 ); urotergite VIII with 2+2 combs, lacking the sublateral comb, each lateral comb of 1–3 macrochaetae associated with two cilia, two marginal setae and a setula; urotergite IX without combs but with a cilium and 2–3 small setae or setulae in each infralateral corner ( Fig. 198 ). Urotergite X ( Fig. 199 ) round (L/ W 0.37, range 0.27–0.39) with numerous macrochaetae, setae and cilia along the lateral and slightly away from the margins, posterior margin usually glabrous for a short region in the middle; lacking posterolateral submarginal macrochaetae.

Urosternite I glabrous, urosternites II–IV with 1+1 lateral macrochaetae each associated with a laterad cilium and a setula, urosternites V–VII (VIII in male) similar but each bearing a pair of styli ( Figs. 200–202 ), each macrochaeta associated with several setulae, the corner laterad to each stylus with a cilium and a few setulae; the posterior margins of urosternites I–VII slightly concave. Five pairs of styli present (on urosternites V–IX) in both sexes, the styli on V–VIII only half the length of styli IX but still armed with several strong setae apically. Posterior margin of urosternite VIII in male with slightly convex posterior margin.

Coxites VIII of ♀ ( Fig. 203 ), with rounded inner process each bearing a single macrochaeta mediad of the base of the stylus. Coxite IX of ♀ with apically acute internal process about three times longer than the external proc- ess (range 2.83–3.39) and 1.7 times longer than wide at its base (range 1.5–1.9), external process with six or seven robust setae near the apex, internal and external margins of inner process with several strong setae or macrochaetae, inner process with a macrochaeta mediad of the base of the stylus insertion. Ovipositor long about 2.4 times as long as HW (range 2.26–2.64) surpassing the end of the inner process of coxite IX by about three and a half times the length of the inner process (and by more than five times in the specimen from Marlborough K.261315), composed of about 41 divisions (range 41–42). Distal divisions of gonapophyses ( Fig. 204 ) with only short fine setae and short rod-like setae .

Cerci ( Figs. 205, 206 ) with basal division(s) unclearly subdivided, the most basal appearing to have three nascent rings, following two divisions shorter than wide each with a single ring of setae and trichobothria, next two divisions with two rings, the basal of which may bear lanceolate scales, divisions then progressively longer with three then four rings of setae and several trichobothria, with larger macrochaetae restricted to the most apical ring, the more basal mostly of lanceolate scales. The lanceolate scales are difficult to see and some of them could also be narrow triangular scales. Subsequent divisions with the number of rings gradually increasing to at least seven rings with the lanceolate scales apparently absent from the apical ring but probably present on all others. The most distal surviving divisions with nine rings with macrochaetae present on the fifth and the most distal, a trichobothrium present on second most basal ring and two trichobothria on the sixth, although these are often very difficult to see (or possibly absent) due to the very dark pigmentation of the caudal appendages. Median dorsal appendage ( Figs. 205, 207 ) with basal two or three divisions covered by the well pigmented epiproct, the next two divisions also short with only a single ring of long setae, some trichobothria and cilia, next two divisions increasingly longer with two rings, following divisions with three then four rings with probable lanceolate scales present in the penultimate rings. Most distal surviving divisions with nine rings, shorter and more densely setaceous than the cerci, with macrochaetae only on the 5 th as well as the most distal annuli, trichobothria on the 3 rd, 6 th and 7 th annuli.

Each coxite IX ( Fig. 208 ) of male with a macrochaeta mediad of the base of each stylus, several strong macrochaetae along the inner and outer margins of the inner process and apically plus laterally on the outer process; the internal process acute, about 1.25 times longer than wide at its base (range 1.16–1.36) and 3.8 times as long as the outer process (range 3.45–3.94) which is shorter than wide at its base (L/ W 0.59) and rounded (N. B. left internal process of illustrated paratype is deformed). 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 long, conical with about 30 long thin setae ( Figs. 208, 209 ).

Habitat. Collected using pyrethrum spray to the soft bark of trees on the edge of rainforest or to ironbark trees.

Etymology. Named from the Latin adjective tenebrosum referring to the dark colour of the end of the abdomen in alcohol, caused by the strong pigmentation and/or sclerotization of urotergite X, coxites IX, epiproct and paraprocts.

EASTERN NSW GROUP

Figures

FIGURE 38. Visma tenebrosum left anterior corner of frons with large scales over-hanging the anterior margin, clypeus with variety of narrow triangular scales, and labrum with macrochaetae. Scale bar: 0.1 mm.

FIGURE 41. Visma tenebrosum n. sp., t-annulus of antenna. Scale bar: 0.01 mm.

FIGURE 44. Visma tenebrosum n. sp., insertion and trichobothrium of second tarsal article. Scale bar: 0.01 mm.

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 16–20. Notal scales. 16. Visma aff. brigalowsum, note greatly different rib spacings. 17. Visma tenebrosum n. sp. including one of the scales with wider rib spacing. 18. Visma xanthorrhoea n. sp. 19. Visma aff. stilivarians. 20. Visma bundjalung n. sp. Scale bar: 0.01 mm.

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 174–183. Visma tenebrosum n. sp. holotype ♀ 174. Habitus. 175. Round scale from urotergite. 176. Head. 177. Antenna, scape, pedicel and basal intervals of flagellum. 178. Idem, most distal surviving interval. 179. Mandible. 180. Idem, incisor and molar regions. 181. Maxilla, smaller setae omitted from palp. 182. Idem, lacinia. 183. Labium, smaller setae omitted from palp. Scale bars = 0.1 mm unless otherwise indicated.

FIGURES 184–191. Visma tenebrosum n. sp. holotype ♀ 184. Pronotum, left side. 185. Idem, right anterior trichobothrial area. 186. Idem, right posterior trichobothrial area. 187. Mesonotum, left margin. 188. Idem, detail of trichobothrial areas. 189. Metanotum, left margin. 190. Idem, detail of right trichobothrial areas. 191. Presternum, prothoracic sternum and PI. Scales: 0.1 mm.

FIGURES 192–202. Visma tenebrosum n. sp. holotype ♀ 192. Mesothoracic sternum and PII. 193. Metathoracic sternum and PIII (separated at trochanter/femur suture). 194. Urotergite II (missing left submedial macrochaeta). 195. Urotergite VII, left lateral combs. 196. Idem, left sublateral comb. 197. Left submedial comb. 198. Urotergite IX, detail of right infralateral chaetotaxy. 199. Urotergite X. 200. Urosternite III, right submedial macrochaeta. 201. Urosternite VI and styli. 202. Idem, detail of chaetotaxy at base of left stylus. Scales: 0.1 mm.

FIGURES 203–209. Visma tenebrosum n. sp. holotype ♀ unless otherwise indicated with specimen number 203. Coxites VIII and IX, and ovipositor. 204. Apices of ovipositor valves. 205. Base of cercus and median dorsal appendage. 206. Apical division of cercus. 207. Apical division of median dorsal appendage. 208. Coxites IX, styli, parameres and penis (K.261282). 209. Paramere (K.261282). Scales: 0.1 mm.

FIGURES 376–385. Visma stilivarians (Silvestri) holotype ♀ 376. Pronotum, anterior and left margins. 377. Idem, anterior trichobothrial area. 378. Idem, posterior trichobothrial area. 379. Idem, right comb of posterior margin. 378. Mesonotum, left margin. 381. Idem, detail of trichobothrial areas. 382. Metanotum, left margin. 383. Idem, detail of trichobothrial areas 384. Presternum, prothoracic sternum and PI. 385. Mesothoracic sternum and PII. Scales: 0.1 mm.