Visma brayi, 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 : 78-85

Visma brayi new species

Table 9; Figs. 268–294

Type material. Holotype NSW: “Winmurra”, Doyles River , 50km NW of Taree, 31.516°S 152.241°E 520 m asl, 27.vi.2018, David Bray, cracks decaying eucalypt log, ♀ ( HW 1.63 ) on two slides (K.541540) . Paratype ♂ ( HW 1.48 ) same data as holotype , on two slides (K.541529). Other paratypes: ♀ ( HW 1.13 ) on two slides (K.541541) ; five ♂♂ one ♀ one juvenile, in alcohol (K.385362), all same data as holotype .

Diagnosis. This species can be distinguished from other species in the Eastern NSW group as follows: from V. bundjalung n. sp. and V. bingara n. sp. by the presence of six pairs of styli (versus five) and from V. advenum n. sp. by the more anterior position of the anterior trichobothrial area of the pronotum (average 0.36–0.42 versus 0.48).

Description. Medium sized silverfish, thorax at pronotum about one quarter wider than abdomen which only tapers slightly posteriorly from about the fifth abdominal segment.

Body length up to 9.5 mm (specimen with HW 1.48 mm); thorax: length about one third H+B; width up to 2.4 mm with mesonotum slightly wider than the pro and metanota; antennae about 0.85 H+B; terminal filaments incomplete in all specimens measured.

Pigment brown or reddish brown. Flagellum of antennae evenly light brown; pedicel with distinct medium density patch of pigment above, scape with faint circum-distal ring of pigment. Terminal filaments annulated light brown with only the distal most one or one and a half annuli in each repeated chain lacking pigment. Head with pigment around eyes which faintly extends mediad onto the frons, pigment along lateral margins to peri-antennal group which is not pigmented, pigment absent from clypeus, labrum and mandibles. Maxillary palp with medium pigment along the sides and above on the second, third and penultimate articles being faint in the second article and quite strong in the penultimate. Labial palp with comparatively dark pigment along lateral margins of the ultimate article and across the proximal surface but lacking distally and around papillae; penultimate article with pigment over the outer half, second article with a little pigment on the dorsal face. Pigment in anterior corners and along lateral margins of nota. Coxae with medium pigment along outer margin; trochanter with small faint dark patch of pigment posteriorly; femur with obvious dark pigment along much of its posterior margin and distally on the anterior margin; tibia of all legs with light pigment on the dorsal margin distally extending on to the face of the tibia distally and back along most of the ventral margin, more obvious on the dorsal aspect covering most of the surface and strongest distally; first tarsal article strongly pigmented above. Urotergite X with light to medium pigment, coxites IX pigmented especially along the outer margin of the inner process and around the stylus insertion. Styli IX evenly and darkly pigmented, other styli with less pigment becoming absent in the more anterior styli. Parameres lacking pigment or with little pigment.

Macrochaetae smooth, straw coloured to hyaline, apically bifurcate, some with truncated tips to each bifurcation, others with minute bifurcations. Some macrochaetae on tibia, stout carrot-shaped. The more anterior lateral insertion point of the posterior combs of the nota almost certainly occupied by a long, thin trichobothrium-like seta.

Round scales variable in size and shape ( Fig. 267 ) but all with ribs quite close together, mostly hyaline ventrally, dorsal scales with brown ribs. Hyaline triangular scales present on femora and tibia ( Fig. 268 ), scape as well as on styli IX; clypeus with narrow triangular scales, that appear to have more rounded or flattened apices ( Fig. 269 ). Scales present on the basal divisions of the terminal filaments appear to be of both narrow triangular and lanceolate form.

Head wider than long ( Fig. 270 ), without distinct bushes. Frons with glabrous anterior margin, a single line of 5–11 macrochaetae on the anterior lateral margins of the frons before widening to two macrochaetae just before the antennae and to about three to four macrochaetae wide after the antennae; there is a small gap (less than one macrochaeta wide) between these rows and the rows of strong macrochaetae before and above the eyes; peri-antennal group about 5–9 macrochaetae wide with some cilia and a long thin trichobothrium at the mediad end. Clypeus quite reduced and folded back somewhat under the anterior margin of the frons, with 2+2 strong macrochaetae medially as well as 1+1 small combs of 2–3 macrochaetae laterally near the suture with the frons, the face of the clypeus covered in narrow triangular scales, some cilia and a few setulae. Labrum longer than clypeus with many strong macrochaetae distributed across the proximal half and some smaller setae in the anterior half. Scape of antenna ( Fig. 271 ) with triangular scales on lateral faces, pedicel with setae on lateral faces; both with a subapical ring of strong setae and some cilia on the pedicel. First and second annuli of flagellum with 1–2 rings of setae with at least one small trichobothrium per ring, third to eighth annuli with a single ring including also some cilia, ninth annulus shows the beginning of division into two annuli per interval with just a few setae on the basal part of the interval, clearly divided into two annuli by the tenth interval with the trichobothrium restricted to the most distal annulus, further subdivision visible by the fourteenth interval. Most distal surviving intervals (probably about three quarters the length of an intact antenna) divided into repeated patterns of twelve annuli, each with two rings of fine setae, the most distal annulus of each division with at least one trichobothrium, a few rod-like basiconic sensilla (type B) and one type C sensillum.

Mandibles ( Fig. 272 ) robust with well-developed incisor and molar areas; a group of about 12–15 short robust macrochaetae and setae adjacent to molar region and a bush of about 80 macrochaetae externally. Maxilla ( Fig. 273 ) with two thick apically bifurcate macrochaeta externally proximal to the palp; lacinia short and wide, with three strong teeth, one set further back than the other two, followed by seven lamellate processes and a row of ten setae, galea with a stronger setae proximally but otherwise with only short fine cilia; apical article of maxillary palp 4.6 times longer than wide (range 4.2–5.1) and a little longer than the penultimate article (range 1.02–1.27), the ultimate article probably with three slender branched papillae with short arms (only one seen due to shrinkage of the article), basiconic sensilla not seen, last two articles of palp probably with fine setae only, no scales seen on any articles, three basal articles with subapical rings of thicker setae. Labium ( Fig. 274 ) wider than long, postmentum with setae arranged in an irregular row across the anterior third, prementum with transverse and short oblique groups of strong setae and with short and long curved setulae distally; apical article of labial palp, wider than long (L/ W 0.89, range 0.81–0.97), much wider in the largest specimen, with five papillae of the compact type arranged in a line which can be almost straight in the largest specimen or, in the smaller specimens, slightly staggered with the second and fourth papillae slightly more proximal than the others, no other sensilla seen; distally with numerous fine short setae, those proximal and medial longer than those distal with many curled setae; basal article with tuft of short macrochaetae.

Pronotum ( Fig. 275 ) with well-developed setal collar of shorter and longer apically bifurcate macrochaetae and long cilia, the macrochaetae sparser in the medial region; lateral margins with some longer and also smaller macrochaetae as well as cilia and about six submarginal combs, the more anterior two composed of two macrochaetae and the more posterior of just one macrochaeta. Anterior trichobothrium 0.39 along the margin (range 0.36–0.42), not associated with a submarginal macrochaeta, with a setula or cilium but otherwise without any special chaetotaxy. The posterior trichobothrium mediad of a submarginal macrochaeta with some setulae and 1–2 cilia (although this macrochaeta is absent on the illustrated right side of the holotype). Posterior margin with 1+1 posterior combs each of two insertions (only one insertion on the right side of K.541541), the more antero-lateral probably consisting of a very thin trichobothrium-like seta (seen on one alcohol preserved specimen but lost in all other specimens), these insertions associated with two or three cilia and 1–2 setulae. Mesonotum ( Fig. 276 ) with similar lateral chaetotaxy to pronotum except 5–6 combs anterior to the anterior trichobothrial area consist of two macrochaetae, most combs associated with 1–2 setulae posterior to the comb as well as 1–2 cilia; both trichobothrial areas are more posterior than on the pronotum, the anterior trichobothrial area with a macrochaeta mediad of the trichobothrium and the posterior area as in the pronotum; the 1+1 posterior combs usually consist of two insertion points, but only one on one side of K.541529 and one on each side of K.541541. Metanotum ( Fig. 277 ) similar to mesonotum except the posterior trichobothrial even further posterior and lacking the macrochaeta mediad of the trichobothrium; the 1+1 posterior combs consist of two insertion points on most specimens but sometimes the more medio-posterior insertion is quite small; on K.541541, this macrochaeta is still present and is quite thin.

Presternum narrow, with dense transverse row of strong macrochaetae and cilia ( Fig. 278 ). All thoracic sterna free with hyaline round scales. Prothoracic sternum large trapezoidal (L/ W 0.93 range 0.93–0.94) with fine setae along the whole length of the lateral margins, posterior corners each with 1–5 almost marginal macrochaetae and some longer marginal setae, glabrous along the posterior margin or with some fine setae. Mesosternum ( Fig. 279 ) also slightly trapezoidal just slightly wider than long (L/ W 0.97, range 0.95–1.00), with 1+1 combs of 1–2 macrochaetae submarginally in the posterolateral corners with a largely glabrous region between, fine setae and some cilia along the posterior half of the outer margins. Metasternum ( Fig. 280 ) trapezoidal, much wider than long (L/ W 0.67, range 0.64–0.69) with largely glabrous, concave to straight margin between the 1+1 small posterolateral combs each of 1–2 macrochaetae, posterior half of lateral margins with numerous fine setae and some cilia.

Legs ( Figs. 278, 279, 281 ) progressively longer anterior to posterior with the tibia of PIII being 1.7 times longer than that of PI (range 1.5–1.9) and the tarsus of PIII being 1.7 times longer than that of PI (range 1.7–1.8). Tibia L /W ratio of legs PI 2.9 (range 2.7–3.1), PII 3.1 (range 2.5–3.7), PIII 4.1 (range 3.9–4.2); tarsi L/W ratio PI 5.9 (range 5.8–6.0), PII 8.1 (range 8.0–8.1), PIII 9.6 (range 9.2–10.0). Precoxa of PI ( Fig. 278 ) with comb of two to four macrochaetae and some setae on the laterad corner. Coxa of PI without comb in anterior “shoulder” position. Outer margin with numerous long macrochaetae as well as cilia and some small setae, two to three macrochaetae wide, becoming shorter distally; inner margin with about five short strong setae distally over the articulation and about five stronger setae spaced along the distal third of this margin along with smaller fine setae on the dorsal face. Trochanter with some fine setae as well as a long macrochaeta and five or six thicker setae. Femur ventrally with several macrochaetae along the posterior margin and two or three along the anterior margin, distal anterior corner with some smaller setae over the articulation and a line of several setae subdistally on the ventral face, ventral surface with fine setae in the posterior half while the rest is covered with a dense layer of triangular scales which are very prominent along the anterior margin. Tibia with a strong carrot-shaped macrochaeta distally which is about as long as the apical spur as well as some strong longer tapered macrochaetae, posterior margin also with some robust setae about ⅓ along the margin, as well as several smaller setae, dorsal or outer margin with two macrochaetae about half way along the margin and another about ¾ along the margin; apical spur distinctly hooked and bearing several small setae; face of tibia also with setae, some quite long as well as numerous triangular scales along the middle of the article. Tarsi of four articles, the basal tarsal article of PIII about as long as the remaining articles together, bearing some stronger setae below and numerous smaller setae; second article also with two longer setae as well as several smaller setae, this article on all legs also bearing a trichobothrium-like seta about three times as long as the article is wide, third and fourth articles with longer seta ventrally. Pretarsus with two long curved lateral claws and a much shorter medial claw. PII ( Fig. 279 ) and PIII ( Fig. 281 ) similar to PI except first tarsal article on PIII about equal to the other three together, PIII with long thin trichobothrium-like seta about 1.5–2 times as long as the tibia is wide located near the proximal macrochaeta on the dorsal surface; one metatibia of the holotype (illustrated) has at least three more macrochaetae near the outer margin than was seen on any of the other PIII tibia examined, the latter being similar in chaetotaxy to other species in this group .

Urotergite I with 2+2 combs (lacking submedial), each lateral comb of 2–3 macrochaetae associated with a long marginal seta, 2–3 setulae and three cilia, each sublateral comb of two macrochaetae, 1–2 marginal setae, two setulae and three cilia. Urotergites II – VII with 3+3 small combs as shown in Table 9, each lateral comb associated with 1–2 setae and 3–5 setulae between the comb and the margin and 2–5 cilia usually anterior to and between the insertions, each sublateral comb with 1–2 setae and 0–3 setulae and 2–4 cilia, each submedial comb with a small seta plus two cilia ( Figs. 282–284 ) (submedial comb missing on right side of urotergite VI in holotype); urotergite VIII with 2+2 combs, lacking the sublateral comb, each lateral comb associated with 3–5 small setae or setulae and four cilia (submedial comb missing on right side of urotergite VIII in K.541529); urotergite IX without combs but with about four small setae or setulae and a cilium in each infralateral corner ( Fig. 285 ). Urotergite X ( Fig. 286 ) round, short (L/ W 0.34, range 0.33–0.36) with numerous macrochaetae, setae and cilia along the lateral margins, posterior margin with short glabrous region medially .

Urosternite I glabrous, urosternites II–III with 1+1 sublateral macrochaetae each associated with 1–2 cilia and 1–2 small marginal setae or setulae, urosternites IV–VII (VIII in male) also with styli, the 1+1 sublateral combs each of a single macrochaeta mediad to stylus ( Fig. 287 ), each macrochaeta associated with 1–2 long marginal setae, 0–2 cilia and 3–9 fine setulae, the corner laterad to each stylus with 0–2 marginal setae, a cilium and 3–4 fine setulae; the posterior margins of urosternites II–VII slightly concave (but VII almost straight in the female), the posterior margin of urosternite VIII in male distinctly convex ( Fig. 290 ). Six pairs of styli present (on urosternites IV–IX), those on segments IV–VIII less than half the length of the styli on coxites IX, but still armed with several strong setae apically.

Coxites VIII of female ( Fig. 288 ) with rounded inner processes each with a macrochaeta subapically adjacent to the stylus, inner and outer margins of inner process with several setae, outer process with a few apical setae. Coxite IX of female with narrow apically acute internal process about 4.6 times longer than the external process (range 3.6–5.3) and 1.9 times longer than wide at its base (range 1.5–2.2) usually with a macrochaeta inserted mediad of the stylus, external process shorter than wide at its base (L/ W 0.5, range 0.51–0.54) with about five or six robust setae near the apex, internal and external margins of inner process with several strong setae or macrochaetae. Ovipositor ( Fig. 288 ) long about 2.2 times as long as HW, composed of about 44–46 divisions; surpassing the end of the inner process of coxite IX by almost four times the length of the inner process. Distal divisions of gonapophyses ( Fig. 289 ) with short fine setae and setulae only.

Terminal filaments incompletely preserved in slide-mounted material. Cerci ( Figs. 291, 292 ) with three or four basal divisions not well defined (fused?), each with a ring of setae, trichobothria and cilia, following division short with similar ring, next two divisions with two rings, the basal of which appears to have some lanceolate or narrow triangular scales, following two divisions with three rings, the scales probably found in both proximal rings, following division with four rings, the basal three probably with scales; the most distal surviving divisions (about ⅓ length of complete cercus?) divided into four annuli, each with two rings of setae, trichobothria and cilia as illustrated ( Fig. 292 ), the larger macrochaetae restricted to the most distal annulus. Median dorsal appendage ( Fig. 292 ) with first division covered by the epiproct, the next two divisions short with just a single ring of setae and cilia, the next two divisions with two rings, the basal of which has scales, the following two divisions with three rings with scales in the basal two rings, following divisions with four rings, the basal three with scales.

Each coxite IX of male ( Fig. 293 ) with numerous strong macrochaetae along the inner and outer margins of the inner process and apically plus apically on the outer process; the internal process narrow acute, about 1.4 times longer than wide at its base (range 1.2–1.5) and 3.4 times as long as the outer process which is shorter than wide at its base (L/ W 0.6). Styli IX long with several stronger setae distally and along the shaft, the stylus (excluding the apical macrochaetae) about two and a half times the length of the internal process. Penis typical with numerous glandular setae apically, each set on a protuberance. Parameres short, conical, with about 40 thin setae, no indication of a subdivision into two segments was seen ( Fig. 294 ).

Habitat. Collected from cracks in a section of partly decomposed eucalypt log lying on eucalypt forest floor for more than 10 years.

Etymology. Named after the collector, David Bray, a volunteer at the Australian Museum.

Remarks. While very similar in morphology to the other species in this group ( V. advenum , V. bingara and V. bundjalung ), molecular data gives quite strong support for considering it to be a unique species. The currently available material can be separated from V. bundjalung and V. bingara by the number of styli but as mentioned above this character may not be stable. The ovipositor appears to be longer than seen with V. bundjalung specimens from both Boonoo Boonoo and Grafton (2.2 HW versus 1.8–1.9) and with more divisions (44–46 versus 39–41) but data from more specimens from a wider range of localities would be useful (females of V. bingara and V. advenum are unknown).

Figures

FIGURES 267–274. Visma brayi n. sp. holotype ♀ unless otherwise indicated by specimen number 267. Round scale of mes- onotum. 268. Triangular scale of femur PI. 269. Apically rounded narrow triangular scale of clypeus. 270. Head (cross-hatched area obscured by eye pigment). 271. Antenna, scape, pedicel and basal intervals of flagellum (K.541529). 272. Mandible. 273. Maxilla, smaller setae omitted from palp, ultimate article somewhat shrunken. 274. Labium. Scales: 0.1 mm.

FIGURES 275–281. Visma brayi n. sp. holotype ♀ 275. Pronotum, anterior and right margins. 276. Mesonotum, right margin. 277. Metanotum, right margin. 278. Presternum, prothoracic sternum and PI. 279. Mesothoracic sternum and PII. 280. Metathoracic sternum. 281. PIII. Scales: 0.1 mm.

FIGURES 282–290. Visma brayi n. sp. holotype ♀ unless otherwise indicated by specimen number 282. Urotergite IV. 283. Left lateral comb of urotergite VI. 284. Left sublateral comb of urotergite VI. 285. Left infralateral comb of urotergite IX. 286. Urotergite X. 287. Left stylus insertion of urosternite VII. 288. Right coxites VIII and IX and ovipositor. 289. Apices of ovipositor valves. 290. Urosternite VIII of ♂ (K.541529). Scales: 0.1 mm.

FIGURES 291–294. Visma brayi n. sp. holotype ♀ unless otherwise indicated by specimen number 291. Base of cercus and median dorsal appendage. 292. Cercus, most distal surviving division. 293. Left coxite IX, stylus, paramere and penis of ♂ (K.541529). 294. Right paramere (K.541529). Scales: 0.1 mm.