Anisolepisma aquilonaridum, Smith, 2016

Smith, Graeme B., 2016, Revision of the Genus Anisolepisma (Zygentoma: Lepismatidae: Acrotelsatinae), Records of the Australian Museum 68 (6), pp. 269-312: 279-295

publication ID

http://doi.org/ 10.3853/j.2201-4349.68.2016.1662

persistent identifier

http://treatment.plazi.org/id/03F087CD-AF01-5B14-FC36-F9BCFC9FFEF3

treatment provided by

Felipe

scientific name

Anisolepisma aquilonaridum
status

n. sp.

Anisolepisma aquilonaridum   n. sp.

Figs 2–3 View Figures 2–5 , 6–18 View Figures 6–7 View Figures 8–9 View Figures 10–11 View Figures 12–13 View Figures 14–15 View Figures 16–17 View Figure 18 , 20–22 View Figures 20–21 View Figure 22 , 74–113 View Figures 74–85 View Figures 86–93 View Figures 94–105 View Figures 106–113 , 191 View Figure 191

Type material. Holotype ♀ ( HW 0.95) (QM T234162 on two slides) QLD: Bladensburg National Park (near Winton ), 22.54617°S 143.05459°E 232 m asl, 10.iv.2011, Graeme Smith GoogleMaps   . Paratypes: 1♂ ( HW 0.93) (QM T234163 on two slides), same data as holotype GoogleMaps   ; 1♂ ( HW 0.75 mm) ( AMS K 377712 in 80% ethanol), same data as holotype GoogleMaps   ; 1 juvenile ♀ ( HW 0.88) ( AMS K 377713 in 80% ethanol), same data as holotype GoogleMaps   ; 1 juvenile ♀ ( HW 0.70) (authors collection in 100% alcohol), same locality as holotype GoogleMaps   , 8.viii.2013, Graeme and Louise Smith; 1♀ ( HW 1.00) (used for SEM), same data as previous GoogleMaps   ; 1♂ ( HW 1.05) ( AMS K 377714 in 80% alcohol), Bladensburg National Park, Skull Hole 22.55789°S 143.00044°E 204 m asl, 8.viii.2013, Graeme Smith GoogleMaps   .

Other material examined: QLD: 1♂ ( HW 1.0) ( AMS K261122, K261123 on two slides), c. 25 km N. Augathella , 25.58235°S 146.60162°E 396 m asl, 14.viii.2013, Graeme Smith. WA GoogleMaps   : 1♀ ( HW 0.96) ( WAM E89191 View Materials on two slides) North West Cape , 6 km south Exmouth 22.000°S 114.1167°E 10 m asl, 27.ix.2008, Graeme Smith GoogleMaps   ; 1♀ ( HW 0.96) ( IICT in 80% ethanol), same data as previous GoogleMaps   ; 1♂ ( HW 0.79) same data as previous ( WAM E89192 View Materials on two slides) GoogleMaps   ; 1 juvenile ♀ ( HW 0.70) ( AMS K 377715 in 80% ethanol) North West Cape , Shot Hole Canyon Road, 1st major creek crossing, 22.05°S 114.083°E 20 m asl, 27.ix.2008, Graeme Smith GoogleMaps   ; 1 juvenile ♂ ( HW 0.74) ( IICT in 80% ethanol), same data as previous GoogleMaps   ; 1♂ ( HW 0.83) ( WAM E89193 View Materials on three slides), Barrow Island , 20.79761°S 115.4408°E, 15.iii.2006, S. Callan GoogleMaps   , R. Graham (three slides)   , GP7 pitfall trap.NSW   : 1♀ ( HW 1.13) ( AMS K260968 K260969 on two slides), east of Narromine (32.24117°S 148.36373°E 250 m asl), 22.v.2012, Graeme Smith GoogleMaps   ); 1♀ ( HW 0.98) ( AMS K 377716 in 80% ethanol), same data as previous GoogleMaps   ; 1♂ ( HW 1.08) ( AMS K261044 K261045 on two slides), east of Cobar (31.51990°S 146.02925°E 246 m asl) 22.v.2012, Graeme Smith GoogleMaps   ; 1 juvenile ♀ ( HW 0.78) ( AMS K261042 K261043 on two slides), 74 km west of Wilcannia , Spring Creek rest area (31.72279°S 142.68649°E 199 m asl), 21.v.2012, Graeme Smith GoogleMaps   .

Diagnosis. Distinguished from other species of the genus by the presence of only 2+2 combs on urotergite VIII, the presence of five trichobothria-like hairs on each side of the pronotum and four on each side of the meso and metanota, the glabrous urotergite IX and the presence of medial combs on urosternites I–VII (in ♀) or I–VIII (in ♂).

comb of urosternite I; (21) stylus IX and base of cercus.

Description

This description is based on material from the type locality only. Where differences were noted in specimens from other localities, the differences are shown in square brackets.

Appearance: Small to medium silverfish with elongate body ( Fig. 2 View Figures 2–5 ) with thorax only slightly wider than abdominal segment I, following abdominal segments remain about the same width up until about the fifth abdominal segment after which they slowly taper to about ⅔ times the width of the thorax in segment IX. Antennae and terminal filaments incomplete but probably considerably shorter than H+B. Scale pattern in live specimens ( Figs 2, 3 View Figures 2–5 ) dark mottled silver with white lateral margins to the nota, dark scales on pedicel and legs and with antennae, terminal filaments and tarsi pinkish brown.

Body size: H+B length up to about 8.5 mm; HW 1.05 mm [Narromine AMS K260968 1.13]; thorax: length up to 2.55 mm (0.28–0.35 times H+B [Barrow WAM E89193 View Materials 0.27 H+B]); width up to 1.65 mm [Narromine AMS K260968 1.70]; antennae and terminal filaments incomplete in all specimens from type locality, longest remaining portion of antenna in types>0.63 times H+B (Narromine AMS K377716 complete or almost complete at 0.47), of cerci>0.85 times H+B [Narromine AMS K260969 and K377716 complete or almost complete at 0.44–0.48] and median dorsal appendage>0.54 times H+B [Narromine AMS K260969 complete or almost complete at 0.48].

Pigment: Generally brown or yellowish brown; the pigment appears to fade over time (a few years) in weakly pigmented specimens on slides [specimens from North West Cape and Barrow Island were much less pigmented (almost absent in some specimens) than those from Bladensburg while those fromAugathella and NSW showed more pigment but the basic distribution patterns were similar]. Some pigment present around the eyes, antennae with light even pigmentation becoming more pigmented distally, narrow lighter region around joints between articles; ultimate article of maxillary palp with little pigment, penultimate and third articles more strongly pigmented and less so on the second article where it is strongest distally, basal article lacking pigment; labial palp pigmented lightly on ultimate and penultimate articles; nota with light pigment along lateral margins strongest anteriorly; coxae with light pigment only along outer margin; trochanter with little pigment, only at outer distal end; femora with light pigment over much of surface but denser along posterior margin especially on the bulging area and more distally; tibia with some pigment over much of surface but slightly darker distally, tarsal articles with some pigment, more so on basal articles; styli pigmented, urosternites IX pigmented, more so around the stylus insertion and along the outer margin of the inner process; terminal appendages quite darkly pigmented however terminal filaments appear almost pinkish white in live specimens; ovipositor with overall light brown pigment.

Scales: Quite variable in shape, dorsal scales on alcohol preserved specimens appear dark brown, ventral scales clear, those on legs, pedicel, scape, basal four articles of maxillary palp, penultimate article of labial palp and clypeus brown or clear. Scales on slide material appear dark brown/black or clear, rounded or ovoid, with numerous parallel rays that do not or only minutely extend beyond the margin of the scale ( Figs 7 View Figures 6–7 , 74, 75 View Figures 74–85 ).

Macrochaetae: Bifid apically or simple, hyaline or yellow/ brown ( Figs 6 View Figures 6–7 , 76 View Figures 74–85 ).

Head: Wider than long, with scales above; chaetotaxy well developed ( Figs 8, 9 View Figures 8–9 and 77 View Figures 74–85 ), frons with isolated 1+1 anterior groups of about 70–80 strong, apically bifurcate macrochaetae located on bulges of the anterolateral corners (fewer macrochaetae on smaller specimens) [50–90 on specimens from North West Cape depending on specimen size]; a distinct hollow exists between these bulging rounded corners; lacking macrochaetae along lateral margins above antennae; behind each antenna and before the eyes is a U-shaped group of setae, the anterior arm of this group terminates in a long, thin trichobothria-like seta and the longer posterior arm extends over the eye. Clypeus with 1+1 combs of three to four macrochaetae [Narromine AMS K260968 five] near the anterior combs of the frons and a line of simple setae (two of the setae much longer than the others as seen in Fig. 8 View Figures 8–9 ) well behind the anterior margin and a band of scales between the combs and the line. Labrum with numerous simple setae in a transverse subposterior band and a line of six fine setae subapically. Eyes dark, composed of about 12 or 13 ommatidia. —Antennae incomplete, scape slightly longer than wide, pedicel not much shorter than scape (0.65–1.00), both of which are covered in scales below the subapical rosette of setae. Each annulus/interval from about the sixth subdivided into two very similar annuli with a trichobothrium subapically on the most distal annulus, the annuli within an interval becoming ever more obvious and longer and by about the ninth subdivide again; each annulus in distal portion of antenna ( Figs 10, 11 View Figures 10–11 , 78 View Figures 74–85 ) with basiconic sensillae (types B and C) distally, the arrangement of which is not yet well established but the type C sensillae appear to occur only in the annuli of the basal half of an interval, the type B sensillae are more numerous occurring on most annuli but numerous on the most distal annulus of an interval; the apical annulus of each interval appears to have one or two subapical trichobothria above and another below, at least until the eleventh interval after which it appears to revert to one above and one below and at least two longer thin hooked setae on each subarticle. —Mandibles ( Figs 79–81 View Figures 74–85 ) with well-developed incisor and molar regions, the molar region on one side with pronounced comb which is lacking on the other molar, a group of four to seven apically bifurcate stout macrochaetae beyond the molar region [North West Cape E89191 View Materials and E89192 View Materials with seven to eleven, Narromine AMS K260968 with eleven], and a bush of>100 macrochaetae and setae externally (fewer on smaller specimens). —Maxilla ( Fig. 82 View Figures 74–85 ) with galea longer than lacinia (although in the holotype (T234162) one lacinia is longer than the galea but this is believed to be an artefact of preparation), lacinia with two large apical teeth and a pre-apical tooth almost as large as those apically, and several lamellate processes, the most distal two of which are truncate or rounded and lie parallel to and extending beyond the apical teeth of the lacinia; proximal to the lamellae is a row of four to seven thin, simple, delicately apically bifurcate setae, apical article of maxillary palp ( Fig. 12 View Figures 12–13 ) 3.4–5.5 [North West Cape AMS K377715 3.2] times longer than wide (more elongate in larger specimens) with a basiconic sensilla (type C) which is not always visible depending on the orientation of the palp on the slide as well as a basiconic sensilla (type B), penultimate article similar in length or slightly shorter than ultimate article, third article with few stout setae subapically, second article with rosette of stronger setae [Narromine AMS K260968 setae are longer, less robust and less rosette-like]; articles (except ultimate) with some small round scales on the outer margin, especially basally. —Labium ( Fig. 84 View Figures 74–85 ) short and broad, prementum with rows of strong setae at the base of the glossae and paraglossae, postmentum with short medial row of three setae (possibly better interpreted as two shorter rows of one and two together) [North West Cape specimens 4–7 setae] and 1+1 lateral groups of one to two [Narromine AMS K260968 three] lateral setae; there are fewer setae in all groups in smaller specimens; labial palp short, apical article rounded subrectangular ( Figs 13 View Figures 12–13 , 85 View Figures 74–85 ), longer than wide (L/W 1.29–1.77) [Narromine AMS K260968 1.82] subequal in length to penultimate article, with four papillae of the “aufgelöst” type arranged in a diamond configuration in the centre of the article rather than apically (see comment on aberrant individual in the discussion section), with two short rounded basiconic sensillae (type C), penultimate article with some stronger setae on the bulge, all articles with scales visible on the margins especially basally.

Thorax: Pronotum ( Figs 14–16 View Figures 14–15 View Figures 16–17 , 86 View Figures 86–93 ) without setal collar but with numerous scales that extend forward over the “neck”, with 1+1 closed tufts on the disc behind the anterior margin mediad of the eyes, each of seven to nine erect macrochaetae in two irregular sub-parallel rows with two or three cilia at the posterior end ( Figs 14 View Figures 14–15 , 86 View Figures 86–93 ); lateral margins fringed with shorter and longer, stout, apically bifurcated setae; anterior corners with three or four medium sized apically bifurcated setae followed by five larger submarginal macrochaetae at intervals (m 0 – m- 4 in Fig. 86 View Figures 86–93 ). The arrangement of these macrochaetae is not very consistent, for example m-3 is missing from the right side of the pronotum of T234163 but is clearly present on the left side and the most posterior macrochaeta (m 0) is missing from the left margin of a specimen from North West Cape ( E89191 View Materials ) but present on the right. Five very long trichobothria-like setae are found at intervals along the lateral margins, the most anterior trichobothria-like seta (tr-4) is located about ¼ the way along the margin anterior to macrochaeta m-2, the second (tr-3) about half way along the margin anterior to macrochaeta m-1, the next (tr-2) is anterior to macrochaeta m 0 and the last two (tr-1, tr 0) are fairly close together near the posterolateral corner ( Fig. 86 View Figures 86–93 ). Posterior margin glabrous but also with numerous dense overlapping scales that make it difficult to discern the margin of the nota in whole specimens. —Mesonotum ( Figs. 17 View Figures 16–17 , 87, 88 View Figures 86–93 ) lacking anterior tufts, almost as long as pronotum along mid-line, with four (rarely five) submarginal macrochaetae (m 0 – m-3) and four long trichobothria-like hairs (tr 0 – tr-3), the first trichobothrium (tr-3) about half way along the margin on the margin just before submarginal macrochaeta m-1, the next (tr-2) close to the margin just in front macrochaeta m 0, and the last two (tr-1, tr 0) away from the margin close to each other in the posterior corners. In one specimen (holotype) an additional submarginal macrochaeta socket (m +1) occurs on the left posterior corner just behind and mediad of tr-1; this macrochaeta socket was not seen on the right side nor on the slide mounted paratype T234163. Posterior margins with 1+1 sublateral single insertion sockets ( Fig. 89 View Figures 86–93 ), each associated with a smaller seta closer to but not on the margin and a cilium; these sockets appear quite small and it is not possible to tell if they are for setae or trichobothria-like hairs) [it was not possible to discern new setae forming under the old cuticle in a specimen from North West Cape which was about to moult (AMS K377715) although the marginal setae were visible, suggesting that these insertion points may be for trichobothria-like hairs, but on a specimen from (AMS K260968) there was a distinct strong macrochaeta about ¼ the length of the mesonotum]. —Metanotum ( Fig. 89 View Figures 86–93 ) slightly smaller than mesonotum but with similar chaetotaxy.

Presternum of prothorax ( Figs 18 View Figure 18 , 90 View Figures 86–93 ) large, clearly visible extending across the underside of the head anterior to the coxae and sternum, about 3.7–4.0 times as wide as long. —Prothoracic sternum not free, partially concealed by coxae ( Figs 18 View Figure 18 , 90 View Figures 86–93 ), anterior medial region of sternum raised into a triangular ridge with triangular field of about 20 simple or apically bifurcate macrochaetae [Barrow WAM E89193 View Materials , North West Cape E89191 View Materials and E89192 View Materials with 28–32, Narromine AMS K260968 with 35, Cobar AMS K261044 with 23]. —Mesosternum ( Fig. 91 View Figures 86–93 ) and metasternum ( Fig. 92 View Figures 86–93 ) also not free but raised and cordiform such that the anterior internal margins of the coxae can fit against the outer edges of the medial part of the sternum with the coxae covering the oval-shaped lower rounded lobes; the distal ⅔ of the lateral margins of the raised cordiform area with 10–11 setae along each lateral margin and a few minute setae anteromedially; surface covered with hyaline scales. —Metasternum similar but slightly wider.

Legs not particularly long ( Figs 91, 93 View Figures 86–93 , 94 View Figures 94–105 ); tibia L/W ratio of legs PI 2.5–3.6 [North West Cape E89191 View Materials 3.7], PII 2.8–3.1 [2.6–3.2], PIII 2.7–3.3; tarsi L/W ratio PI 4.5–6.0 [Wilcannia AMS K261042 4.3], PII 5.1–6.4, PIII 6.0–7.0 [North West Cape E89192 View Materials and Narromine AMS K377716 both 7.2]. —Precoxa with a macrochaeta and zero to two small setae and a cilium. —Coxa of prothoracic leg ( Fig. 93 View Figures 86–93 ) with comb of five long macrochaetae on each “shoulder” [Narromine AMS K260968 seven macrochaetae], a shorter comb of two macrochaetae below it and a line of long erect macrochaetae and shorter setae along exterior margin, rounded scales dorsally which are especially noticeable on anterior margin as well as a comb of two long thin setae on the dorsal face about half way along the coxa near to the medial margin and several setae apically covering the articulation with the trochanter. —Trochanter probably without scales. —Femur with scales, more obvious on leading edge, with several strong spines and longer macrochaetae along posterior edge, apically with insertion points suggesting at least two or three strong spines over the articulation. —Tibia well scaled especially above and along lateral margins, with very robust stout macrochaetae near posterior margin (two pairs plus a more distal single macrochaeta which is longer than the apical spur, as well as other strong setae especially distally; two pairs of stout macrochaetae on outer margin and some strong setae distally near usual apical spur which has several long fine setae in basal half. —Tarsi ( Fig. 20 View Figures 20–21 ) with four articles (although very difficult to discern the suture between the last two); scales present at least dorsally on the basal article and probably basally above on all articles except perhaps the most distal of PI and PII. —Pretarsus ( Fig. 20 View Figures 20–21 ) with long thick straight outer claws that narrow and curve apically, short, thick, smooth, medial empodial.

All urotergal macrochaetae lost from dissected type specimens but some of the marginal setae still present [macrochaetae mostly intact on Narromine specimen AMS K260969 where they are quite long, almost half the length of the respective tergite]. Urotergite I ( Fig. 95 View Figures 94–105 ) with lateral and submedial combs of two strong macrochaetae [AMS K261045 from Cobar with one or two macrochaetae] both with one or two cilia and one or two quite long thin marginal setae. Urotergites II–VII ( Fig. 96–98 View Figures 94–105 ) with 3+3 combs, the lateral combs ( Fig. 97 View Figures 94–105 ) on segments II–III with two [two or three in specimens from Cobar, North West Cape and Narromine] and those on IV–VII with two to three macrochaetae as well as a marginal seta and two or three cilia, the sublateral ( Fig. 98 View Figures 94–105 ) and submedial combs ( Fig. 99 View Figures 94–105 ) each with two macrochaetae [North West Cape and Narromine specimens sometimes with only one macrochaeta], a single small marginal seta and one to three cilia. Urotergite VIII with 2+2 combs, the lateral comb of three macrochaetae [North West Cape specimens two or three] and submedial comb of two macrochaetae also with a single marginal seta and two or three cilia. Urotergite IX glabrous. —Urotergite X parabolic ( Fig. 100 View Figures 94–105 ) 0.51–0.57 times [North West Cape specimens 0.43–0.54] as long as wide with several strong and some finer setae on margin, with 1+1 combs of two or three strong macrochaetae, associated with up to two cilia, in posterolateral corners.

Only one urosternal macrochaeta preserved on dissected type specimens, which is apically slightly bifurcate and less than one third the length of the corresponding sternite ( III) ( Fig. 101 View Figures 94–105 ); medial macrochaetae intact on specimen used for SEM ( Fig. 20 View Figures 20–21 ) about one third to one half the length of the corresponding sternite [macrochaetae mostly intact on the Narromine specimens where they are longer, almost half that of the respective sternite]; marginal setae also quite long but much thinner than macrochaetae ( Fig. 102 View Figures 94–105 ). Urosternite I ( Fig. 103 View Figures 94–105 ) with medial comb of two macrochaetae plus two or three marginal setae [ North West Cape zero to two marginal setae] on small medial bulge on posterior margin. Urosternite II ( Fig. 104 View Figures 94–105 ) with 1+1+1 combs, the submedial combs each of three macrochaetae [ North West Cape three or four, Narromine and Cobar two] and a marginal seta [marginal setae often absent in specimens from North West Cape and Cobar ], the medial comb of two macrochaetae and two marginal setae [often absent in North West Cape and Cobar specimens]. Urosternites III – VII ( Fig. 105 View Figures 94–105 ) in ♀ ( III – VIII in ♂) with 2+1+2 combs, the lateral combs with two to three macrochaetae [ North West Cape of three to five, Narromine and Cobar of two to three] macrochaetae, the submedial combs with three to four macrochaetae [ North West Cape three to five, Narromine sometimes with only two], a marginal seta and sometimes a cilium and the medial comb with two [Cobar with one or two] macrochaetae and usually a marginal seta   .

Coxite VIII in ♀ ( Fig. 106 View Figures 106–113 ) divided into two coxites, each with two combs of three or four macrochaetae [Narromine AMS K260969 of two to four], the submedial comb with two marginal setae, the lateral with one marginal seta and a cilium.

Coxite IX in the ♀ as in Fig. 106 View Figures 106–113 , the internal process acute apically reaching to about ⅔ the length of the stylus [about as long as the stylus in North West Cape E89191 View Materials and longer than stylus in specimen from Narromine AMS K260969], about 3.8 times longer than the external process [North West Cape E89191 View Materials about 4.1, Narromine AMS K260969 about 4.5] and 2.0 times as long as broad at its base [North West Cape E89191 View Materials 2.6, Narromine AMS K260969 2.1], with several strong setae along external margin and a strong macrochaeta adjacent to and medial of the base of the stylus; external process of coxite IX small, triangular with acute apex, a few strong setae subapically and along external margin. — Ovipositor of primary type with very inconspicuous secondary segmentation; more apical divisions of anterior valves with very long thin setae ( Figs 22 View Figure 22 , 106 View Figures 106–113 ). In largest specimen observed, the ovipositor only just extends beyond the end of the inner processes [North West Cape E89191 View Materials extends beyond by about half the length of the inner process and is about the same length as the inner process in the Narromine specimen AMS K260969]   .

Coxite IX in the ♂ as in Figs 107, 108 View Figures 106–113 , the internal process acute apically, about 1.9–2.0 times longer than the external process [Barrow WAM E89193 View Materials 2.1–2.4, CobarAMS K261045 2.8) and 1.0–1.1 times as long as broad at its base [Barrow WAM E89193 View Materials 1.0–1.2], with several strong setae along both margins; external process of coxite IX small, triangular with a few strong setae subapically and along external margin. —Penis ( Fig. 108 View Figures 106–113 ) with numerous small rods/setae apically, each set on a protuberance. —Parameres difficult to differentiate from inner process of coxite IX in slide material of holotype ( Figs 108, 109 View Figures 106–113 ), appear to be long, unsegmented, almost as long as the internal process with numerous long fine setae as well as some stronger setae on inner (ventral) surface; see also illustration of Barrow Island specimen WAM E89193 View Materials ( Fig. 108 View Figures 106–113 ) for clearer representation.  

Styli in one pair (IX only) with several long strong setae ventrally along their length similar to two larger setae at apex ( Figs 21 View Figures 20–21 , 106, 107 View Figures 106–113 ).

Epiproct and paraprocts in both sexes not strongly pigmented/chitinized ( Fig. 110 View Figures 106–113 ) [much more so in specimens from Narromine and Wilcannia, but not Cobar, nor North West Cape nor Barrow], the former developed into a flat, forked process over the median dorsal appendage, the latter with a rounded conical terminal process and more proximal rounded right angled process; cerci with basal division glabrous ( Fig. 111 View Figures 106–113 ), the next division very short with a few small setae and trichobothria and a pointed macrochaeta on the outer face, divisions becoming gradually longer with two annuli, each with a rosette of small setae and trichobothria by the sixth division, three annuli by the eighth, four by the ninth, and six by the thirteenth persisting to the most distal surviving divisions which have both long, strong and smaller, simple setae, trichobothria as well as long fine hooked cilia as shown in Fig. 112 View Figures 106–113 . —Medial dorsal appendage similar ( Figs 110 and 113 View Figures 106–113 ) but with shorter divisions of only four annuli in the most distal surviving articles.

Discussion. In spite of the small differences noted especially in pigmentation and the large distances between collection sites ( Fig. 1 View Figure 1 ) (about 3,000 km between Barrow Island and the type locality) the specimens from the seven localities listed are considered to belong to the same species. The dissected and mounted specimens from Western Australia were much lighter in colour (pigmentation, sclerotization, scale cover?) than specimens from Bladensburg which were not quite as dark as specimens from NSW, initially suggesting that they were different species. However close examination of specimens including comparing measurement data and details of the chaetotaxy failed to identify any character(s) that would unequivocally support this. Minor differences in numbers of macrochaetae and length of antennae etc (as indicated in the description) were not considered significant. It is possible that the darker colouring of specimens is due to their more recent collection and better condition (slightly larger, collected more recently, less handling damage and less time as slide preparation). Differences in pigmentation between individuals in species of other genera (e.g., Heterolepisma   ) are also sometimes seen to be quite variable even within a single population. Given the small number of specimens available and the difficulty of working with insects that moult often and suffer handling damage easily, molecular data might be required before this question is investigated.

Habitat. All specimens were collected from places with fairly low (<550 mm per year) but highly to extremely variable rainfall with long periods without rain quite common ( Table 5). Most Bladensburg specimens were collected by hand from very dry leaf litter on rocky surfaces on a hot exposed ridge in 2011. Another two specimens were collected from the same locality in 2013 and a further specimen from dry leaf litter on soil at Skull Hole about 6 km further west. A total of five specimens were collected by hand in dry leaf litter accumulated in dry creek bed south of Exmouth, WA. The Barrow Island specimen was collected in a pitfall trap. The Wilcannia specimen was collected by hand in dry Casuarina   / Allocasuarina   (?) leaf litter. Two specimens were collected near Narromine by hand during daylight hours under pieces of old dry wood fallen from a large Eucalypt tree. The specimen from Cobar was found in Acacia   leaf litter on red soil.

Etymology. From the Latin words aquilonis for northern and aridus for arid reflecting the distribution of this species across the arid north of Australia.

Comment. This species, while close to A. hartmeyeri   , differs significantly in the chaetotaxy of urotergite VIII and the conversion of the most posterior submarginal macrochaeta on the meso- and metanota to a long, thin trichobothria-like seta.

WAM

Western Australian Museum

IICT

Centro de Zoologia do I.I.C.T.

R

Departamento de Geologia, Universidad de Chile