Anisolepisma subpectinum, Smith, 2016

Smith, Graeme B., 2016, Revision of the Genus Anisolepisma (Zygentoma: Lepismatidae: Acrotelsatinae), Records of the Australian Museum 68 (6), pp. 269-312 : 300-306

Anisolepisma subpectinum n. sp.

Figs 158–189

Material examined. Holotype ♀ ( HW 0.94) ( SAMA 05-000001 on two slides) SA: Mt Chambers Gorge (30.95281°S 139.22484°E 166 m asl), 15.v.2012, Graeme Smith.

Diagnosis. Distinguished from other species of the genus by the 3+3 combs on urotergite VIII, the presence of several basiconic sensillae type B on the apex of the maxillary palp and the absence of medial combs from some urosternites .

Description

Appearance: Small to medium silverfish with elongate body with thorax slightly wider than abdominal segment I, the following abdominal segments remain about the same width until the sixth abdominal segment after which the abdomen slowly tapers to be about ⅔ the width of the thorax in segment IX. Antennae and terminal filaments incomplete. Scale pattern in live specimen mottled silver with light bands on edge of pronotum ( Fig. 4 ) probably due to the overlap of transparent scales along the margins, dark scales on pedicel and dorsal face of tibia of at least PIII; antennae, terminal filaments and tarsi light pinkish brown.

Body size: H+B 7.3 mm; HW 0.94 mm; thorax: length up to 1.98 mm (or 0.27 times H+B); width 1.48 mm; antennae and terminal filaments incomplete, longest remaining portion of antenna 0.40 times H+B, of cerci 0.32 and median dorsal appendage 0.30 times H+B.

Pigment: Brown and often blotchy; antennae flagellum lightly to moderately pigmented with lighter areas at the distal end of each interval/annulus in basal portion of flagellum, pedicel and scape pigmented; head with light pigment around eyes; apical article of maxillary palp with light pigment, penultimate article with slightly more pigment, mostly distally, third article almost completely pigmented but lighter proximally, second article overall dark brown except for basal ring, basal article without pigment; all articles of labial palp with very light pigmentation, thoracic nota with pigment along lateral margins, legs lightly pigmented but darker areas occur on the anterior edge of the femur as well as over the faces near the posterior edge distal to the ventral bulge, tibia evenly but somewhat more darkly pigmented especially distally and along outer or dorsal margin, tarsi with very light even pigmentation; urotergite X pigmented posteriorly, urosternite IX with moderate pigment around stylus insertion and along outer margin of internal and inner margin of external processes, styli well pigmented except at base; parameres and penis with light pigmentation.

Scales: Rounded, subrectangular ( Fig. 158 ) or ovoid or sometimes quite irregularly-shaped, with numerous parallel rays that do not extend beyond the margin, dark brown/ black or clear (the latter more so medially on the urosternites and along the margins of the nota), those on legs, basal articles of palps brown or clear, those on pedicel, scape and clypeus, especially in non-mounted material can look almost black; scales on dorsal surface arranged in transverse rows extending well beyond the posterior margins of the tergites. Scales present on top of head, pedicel and scape, on clypeus, basal four articles of maxillary palp mostly in the basal part of each article, on labial palp, tergites and sternites as well as most leg articles except the more apical articles of tarsi on PI and PII, and at the base of the styli. Absent from flagellum and terminal filaments.

Macrochaetae: Bifid apically or simple, hyaline or yellow/ brown.

Head: Wider than long; chaetotaxy ( Fig. 159 ) well developed, frons with isolated 1+1 anterior groups of about 65–80 strong, apically bifurcate macrochaetae plus two or three cilia, lacking macrochaetae along lateral margins above antennae, a U-shaped row (often more than one macrochaeta wide) starts from a very long thin trichobothria-like seta a short distance onto the frons behind the antennae and runs perpendicular to the margin, turning back along the margin to the eye then running up above the eye to or slightly beyond the posterior level of the eye; clypeus with 1+1 combs of four macrochaetae immediately close to but laterad of the bushes on the frons as well as a row of finer setae (two of which are much longer) across the sclerite about ⅓ its length from the distal suture, the area between the row of setae and 1+1 combs densely covered in dark scales; labrum with area of fine setae across the sclerite about ¼ its length from the suture with the clypeus and another shorter line of finer setae ⅔ distally. —Antennae incomplete; pedicel shorter than scape (about ⅔ its length), both of which are covered in scales below the subterminal rosette of setae ( Fig. 160 ), with small groups of tiny setulae near the base of both the pedicel and scape; annuli/intervals of flagellum begin to subdivide from fourth interval of flagellum with the subdivisions becoming clearer and the individual annuli longer apically, intervals further subdivide from about the eighth interval with short setae as well as both straight and curly trichobothria-like hairs, the straight trichobothria restricted to the distal end of the most distal annulus in each interval; most distal remaining intervals ( Fig. 161 ) without specialized sensillae but each annulus with a subapical ring of basiconic sensillae type B with occasional type C also present. —Mandibles ( Fig. 162 ) with well-developed incisor and molar regions, the molar region typical for genus with one side having a comb of raised spines, the other without the comb but with a pointed projection and three short bifurcated setae behind the molar area; beyond the molar area is a group of one shorter rounded and five or six apically bifurcate macrochaetae and a bush about 90 setae and macrochaetae externally. —Maxilla ( Figs 163–165 ) with galea longer than lacinia, galea with small apical lobe, lacinia with one or two large teeth and one smaller pre-apical tooth, the apical teeth associated with truncate or rounded lamellate processes; six to seven apically acute lamellate processes and a row of five delicately apically bifurcate setae along the inner margin of the lacinia ( Fig. 164 ), apical article of maxillary palp ( Fig. 165 ) 4.6 times longer than wide with at least one small basiconic sensilla type C as well as a few type B sensillae towards the apex, penultimate article shorter than ultimate article (0.8), third article without obviously stouter setae, second article with distinct rosette of stronger setae well back from apex; scales on all articles except ultimate, usually more obvious proximally. —Labium ( Fig. 166 ) short and broad, prementum with rows of strong setae at the base of the glossae and paraglossae (1+1 medial groups each of two setae, 1+1 lateral lines of seven setae) and postmentum with a short medial row of four setae and single lateral setae; labial palp short, apical article ( Fig. 167 ) 1.5 times longer than wide, slightly longer than penultimate article, with four papillae of the “aufgelöst” type arranged in a diamond configuration near the centre of the article rather than apically, with a short curved basiconic sensilla type C on external margin at level of papillae.

Thorax: Pronotum ( Figs 168–170 ) without setal collar but with numerous scales that extend forward over the neck, with 1+1 closed tufts of six erect macrochaetae in two rows and two or three small posterior cilia on the disc behind the anterior margin mediad of the eyes ( Fig. 169 ); lateral margins ( Fig. 170 ) with some shorter and longer, stout, apically bifurcated setae on anterior corner and along the lateral margins along with some cilia, as well as five submarginal strong apically bifurcate macrochaetae on each side (numbered m 0 – m- 4 in Fig. 170 ); four trichobothria-like hairs (numbered tr 0 – tr- 3 in Fig. 170 ) located at intervals along the lateral margins, the most anterior (tr-3) quite long, located about one quarter the distance along the margin anterior to submarginal macrochaeta (m-3), the second (tr-2) almost half way along the margin anterior to submarginal macrochaeta (m-2), the third (tr-1) about ⅞ the distance along the margin just anterior to the most posterior submarginal macrochaeta (m 0) and the last (tr 0) is a little further from the margin in the posterior corner of the notum (tr 0); posterior margin glabrous with numerous dense overlapping scales that make it very difficult to discern the margin of the nota in whole specimens. —Mesonotum ( Figs 171–173 ) about the same length as the pronotum in the midline, lateral margins with five submarginal macrochaetae on each side (numbered m 0 – m- 4 in Fig. 172 ) and three trichobothria-like hairs (numbered tr 0 – tr-2) the first is very long and located on the margin almost halfway along and associated with submarginal macrochaeta m-2, the second is shorter but also on the margin and associated with macrochaeta m 1, the last is also apparently shorter and located in the posterolateral corner a small distance from the margin and posterior to a submarginal macrochaeta m 0; 1+1 macrochaetae on the posterior margin each associated with a marginal seta and two cilia ( Fig. 173 ). —Metanotum ( Figs 174–175 ) slightly shorter than mesonotum but with similar chaetotaxy however the first two trichobothria-like hairs are located slightly more posteriorly.

Presternum of prothorax large, clearly visible extending across segment anterior to the coxae and sternum. — Prothoracic sternum ( Fig. 176 ) not easily visible on slide mount but not free, partially concealed by coxae, anterior medial region of sternum raised into a triangular ridge with triangular field of about 22 insertion sockets. —Mesosternum lost during dissection but observed before dissection to be similar to metasternum. —Metasternum ( Fig. 177 ) also not free and covered by coxae, cordiform with a row of 8–10 long thin simple macrochaetae along or near each lateral margin and six small cilia anteromedially in V-shape; surface covered with hyaline scales.

Legs not particularly long ( Figs 174–175 ), tibia L/W ratio of legs PI 3.0, PII 2.4, PIII 3.1; tarsi L/W ratio PI 5.8, PII 5.9, PIII 6.4. —Subcoxa with a macrochaeta and two cilia. —Coxa of prothoracic leg ( Fig. 176 ) with numerous round scales, a comb of five stout macrochaetae on each “shoulder” and a shorter comb of two macrochaetae below it and a line of macrochaetae running down the outer margin, in the slide mount it appears to run remote from and parallel to the margins however this may be an artefact due to the rolling of the coxae as the slide dried; there is also as a comb of two setae on the dorsal face close to the inner margin about halfway along the coxa. —Coxa of PII and PIII ( Figs 178 , 179 ) without shoulder combs and the comb of two setae on the face is more posterior, distal internal apex with several stronger setae covering the articulation with the trochanter. —Trochanter of all legs simple but with tendency to distort if the femur contracts a long way under the coxa on slide mounts giving the erroneous appearance of two distinct parts to the trochanter. —Femora of all legs with scales more obvious on leading edge with three to eight short stout setae distally over the articulation (more on femur of PIII than the anterior legs), posterior ventral margin with four very stout, thick macrochaetae especially near the bulge, as well as several long strong macrochaetae along the whole length. —Tibia well scaled, anterior or dorsal margin with a pair of stout macrochaetae just short of midway and another pair subdistally, ventral margin with three pairs of stout macrochaetae plus other smaller setae, with another stout macrochaeta on the dorsal face, dorsal surface subdistally with a row of setae; apical spur with several long thin setae arising in the proximal half. —Tarsus with four articles with numerous setae, scales appear to be lacking from more apical articles of tarsus of PI and PII but are present on most articles of PIII. —Pretarsus with long thick outer claws that narrow and curve apically, shorter smooth medial empodial claw ( Fig. 180 ).

Urotergite I with lateral combs of two macrochaetae, a marginal seta and two cilia, the submedial comb, only present on one side in holotype, with two macrochaetae, a thin long marginal seta and a cilium. Urotergites II – VIII ( Fig. 181 ) with 3+3 combs, the lateral combs with two or three ( Fig. 182 ), the sublateral and submedial each with two macrochaetae, a single long thin seta on the margin and one to three small cilia associated with each comb in a regular pattern (one at the distad end of each comb and one between the more distad pair of macrochaetae slightly anterior to the comb and on the more posterior urotergites, another anterior to and between the remaining pair of macrochaetae (urotergite V was lost during slide preparation), on urotergites VI and VII a submedial comb is missing on one side, on VI completely missing and on VII just a single cilium being present. Urotergite IX glabrous. — Urotergite X parabolic ( Fig. 183 ), 0.6 times as long as wide at the base with many strong setae along lateral and posterior margins and combs of two or three macrochaetae plus two cilia in posterolateral corners.

Urosternite I with medial comb of two macrochaetae and a thin marginal seta. Urosternite II with 1+1+1 combs, all of two macrochaetae and a long thin marginal seta, the submedial combs also with one or two cilia. Urosternites III, IV and VI with 2+1+2 combs, the lateral combs with three, the submedial ( Fig. 184 ) with three and the medial with one or two macrochaetae with both lateral and submedial combs associated with one long thin setae marginal seta and a cilium at the laterad end of each comb. Urosternites V ( Fig. 185 ), VII and VIII with 2+2 combs, in the case of V and VII the posterior margin of the urosternite is clearly concave with the medial comb lacking, lateral and submedial combs all composed of three macrochaetae, a long thin marginal seta and a laterad cilium except the right submedial comb of segment VII which has four macrochaetae. —Styli ( Fig. 186 ) in one pair (IX only) with scales at base and several long strong setae ventrally along their length similar becoming stronger distally but not as strong as those at the apex; with single large macrochaeta on coxa mediad to the base of each stylus.

Coxite IX in the ♂ as in Fig. 186 , it was very difficult to discriminate from paramere, the internal process acute apically, about 1.8 times longer than the external process and 1.1 times as long as broad at its base, with several strong setae along external margin; external process of coxite IX small, acutely triangular with a few strong setae subapically and along external margin. —Penis with numerous setae apically, each set on a protuberance. —Parameres difficult to see as they are obscured by coxites IX but they are long, unsegmented, lying very close to and almost as long as the internal process, with simple setae along the mediad margin and apex and numerous long thin setae on the protected inner side of both the parameres and inner process of coxite.

Epiproct and paraprocts moderately pigmented ( Figs 187, 188 ), the former developed into a strong, flat forked process, the latter with a subcylindrical process and a more distal acutely subtriangular medial process. —Cerci and median filament incomplete but at least 0.3 times H+B. Cerci ( Figs 188, 189 ) with at least 13 divisions, the second division shorter than the first, then gradually becoming longer with the sixth division about as wide as long, second annulus appearing in the fifth division and four annuli per division by the seventh which persists to the most apical surviving article with the annuli becoming increasingly longer. — Median dorsal appendage with at least 12 divisions, the basal divisions much shorter than long but becoming gradually longer with the fifth division about as long as wide, each division subdivided into two annuli by seventh and further subdivided into a total of four annuli by the tenth division.

Female unknown.

Comment. This species would appear most closely related to A. hartmeyeri based on the dorsal chaetotaxy but differs in the reduced ventral chaetotaxy and the arrangement of sensillae on the maxillary palp.

Habitat. A single male specimen was found on soil under rocks in the car park along with a specimen of genus Heterolepisma .

Etymology. The species is named subpectinum in recognition of the reduced number of medial combs on the urosternites.

Figures

Figures 158–167.Anisolepisma subpectinum n. sp. holotype ♂ (158) dorsal scale adjacent to submedial comb of urotergite I; (159) head, cross hatched area obscured by eye pigment; (160) antenna, scape pedicel and basal intervals; (161) idem, most distal surviving intervals showing basiconic sensillae type B (bsB); (162) mandible; (163) maxilla, only larger setae of palp shown; (164) idem, apex of galea and lacinia; (165) ultimate article of maxillary palp with basiconic sensilla type C (bsC) and type B (bsB); (166) labium, damaged anteriorly; (167) idem, ultimate articles of palp with basiconic sensilla type C (bsC). Scale bars = 0.1 mm.

Figures 168–178.Anisolepisma subpectinum n. sp.holotype ♂ (168) pronotum with outlineof some scales overlapping margins left anterior and posterior margins; (169) idem, left enclosed tuft of macrochaetae; (170) idem, left lateral margin with submarginal macrochaetae (numbered m0–m-5) and trichobothria-like hairs (numbered tr0–tr-2); (171) mesonotum, damaged right margin; (172) idem, left lateral margin; (173) idem, left posterior comb;(174) metanotum;(175) idem,left lateral margin;(176) prothoracic sternal region and right leg, the displacement of the macrochaetae from the margin is probably an artefact; (177) metathoracic sternum, left;(178) PII. Scale bars = 0.1 mm.

Figures 179–189.Anisolepisma subpectinum n.sp. holotype ♂ (179) PIII;(180) pretarsus;(181) urotergite VIII;(182) right lateral comb of urotergite IV; (183) urotergite X;(184) left submedial comb of urosternite VIII; (185) urosternite V;(186) urosternite IX, penis, parameres and styli; (187) epiproct and base of median dorsal appendage, from below; (188) paraproct and base of left cercus; (189) cercus, most apical surviving divisions. Scale bars = 0.1 mm.

Figures 2–5.Anisolepisma spp.appearance when live(2)A.aquilonaridum n. sp. ex Bladensburg National Park, Qld;(3) A.aquilonaridum ex Cobar, NSW; (4) A. subpectinum n. sp. Mount Chambers Gorge, SA; (5) A. pigmentum n. sp. Ormiston, West MacDonnell Ranges National Park, NT.