Acrotelsella mallee, Smith & Mitchell, 2022

Smith, Graeme B. & Mitchell, Andrew, 2022, On some Silverfish Taxa from the Mildura Region (Inland South-eastern Australia) (Zygentoma: Lepismatidae: Ctenolepismatinae), Records of the Australian Museum (Rec. Aust. Mus.) 74 (5), pp. 151-199 : 158-166

Acrotelsella mallee sp. nov.

urn:lsid:zoobank.org:pub:12995B4B-6498-4FB2-AEA0-45A1A3120B18

Figs 2–34

Holotype ♀ ( HW 1.21 ) NEW SOUTH WALES: Nombinnie Nature Reserve 33.15719°S 145.87153°E 139m asl, 8.vii.2016, Graeme Smith, leaf litter, AMS K.541621 (on two slides) . Paratypes 1♀ ( HW 1.16 ) ca 15km south of Balranald 34.76606°S 143.53946°E 71m asl, 23.ix.2013, Graeme Smith, mallee leaf litter, AMS K.541622 (on two slides) ; 1 juvenile ♀ ( HW 0.75) same data as previous,AMS K.261284 (on one slide) ; 1 juvenile ( HW 0.60) same data as previous,AMS K.377957 (in alcohol) ; 1♀ ( HW 1.13 ) Narrawa 34.41924°S 149.09932°E 495m asl, 4.xi.2014, Graeme Smith, leaf litter, AMS K.541632 (on two slides) ; 3♂♂ ( HW 1.05 , 1.05 , 1.08 ) same data as previous K.377964 (in alcohol) ; 1♂ ( HW 1.05 ) ; 1♀ ( HW 1.20 ) south of Deniliquin 35.82380°S 144.94626°E 108m asl, 5.xi.2014, Graeme Smith, leaf litter, AMS K.541633 (on two slides) ; 1 juvenile ♀ ( HW 0.85) same data as previous,AMS K.377963 (in alcohol). VICTORIA: Wyperfeld N.P., Snowdrift 35.43029°S 141.91111°E 80m asl, 26.ix.2013, Graeme Smith , leaf litter, top of dune,AMS K.261325 (on two slides) ; 1♂ ( HW 0.98) same data as previous, AMS K.261324 (on two slides) ; 1♂ ( HW 1.10 ) same data as previous, AMS K.261325 (on two slides) ; ♂ ( HW 0.93) same data as previous, AMS K.377965 (in alcohol) ; 1♀ ( HW 1.05 ) Pink Lakes turnoff, west of Underbool 35.16731°S 141.70452°E 60m asl, 25.ix.2013, Graeme Smith, hand collected in dry mallee leaf litter, NMV gbs004045 (on two slides) ; 1♂ ( HW 1.05 ) Hattah-Kulkyne N.P. 34.69770°S 142.38873°E 59m asl, 24.ix.2013, Graeme Smith, dry leaf litter under small leaved shrub, top of sand dune, NMV T-22589 (on two slides) ; 1♀ ( HW 1.13 ) Hattah-Kulkyne N.P. dune near Lake Mournpell campsite 34.70198°S 142.33780°E 57m asl, 24.ix.2013, Graeme Smith, leaf litter on sand under small bush, NMV T-22588 (on two slides) ; 1♂ ( HW 1.05 ) 1 juvenile ♀ ( HW 0.75) 1 juvenile ( HW 0.55) same data as previous,AMS K.377958 (in alcohol) ; 1♀ ( HW 1.10 ) Wyperfeld N.P., along road north of Hopetoun 35.53558°S 142.32764°E 99m asl, 27.ix.2013, Graeme Smith, leaf litter of Acacia or pea?,AMS K.541634 (on two slides) ; 1♀ ( HW 1.13 ) same data as previous, AMS K.377967(in alcohol) ; ♂ ( HW 1.05 ) . SOUTH AUSTRALIA: Coorong 35.91°S 139.42°E, 8.xi.2014, Penelope Greenslade, Melaleuca, AMS K. 541623 (on two slides) .

Other material examined but not included in type series. 1♀ ( HW 1.23 ) SOUTH AUSTRALIA: Belair N.P. 36’s site 35.01°S 138.65°E, 2–9.xi.2014, M. A. Nash, pitfall, AMS K.541624 (on two slides); 1♀ ( HW 1.23 ) same data as previous, AMS K.377966 (in alcohol) .

Diagnosis. This species belongs to the group of species with secondary ovipositors, a group in which most currently named species have been inadequately described. It appears to differ from other species by the presence of 7–8 papillae on the labial palp, the 3+3 arrangement of combs on the metasternum and the presence of several short combs along the inner margin of coxites IX of the female.

Description

Appearance: Medium sized silverfish, somewhat stocky in form, thorax wider than the abdomen. Scale pattern when live see figure 3, antennae evenly brown, terminal filaments appear annulated, distinct light margins to thorax. In alcohol specimens become very dark almost as soon as they contact the alcohol.

Body length: H+B up to 8.3 mm, HW 1.21 mm; thorax: length 2.5 mm or 0.27–0.33 H+B; width 2.05 mm with the mesonotum being slightly wider than the pronotum and not much wider than the metanotum. Antennae incomplete, maximum preserved length 4.9 mm or>0.6 H+B; terminal filaments all broken, maximum preserved length of terminal filaments 4.1 mm or>0.5 H+B.

Pigmentation: Cuticle overall quite dark with specimens becoming very dark when they are placed into alcohol. The intensity of darkness makes it difficult to observe macrochaetae insertions in some places. Some variability in darkness noted between specimens. Flagellum of antennae without annulations, moderate orange-brown pigment evenly distributed; pedicel quite darkly pigmented overall or restricted to apical ring of pigment, scape with or without pigment. Frons without darker regions, labrum and clypeus without pigment, mandibles and maxillae without pigment among bushes of macrochaetae, maxillary and labial palps with orange-brown pigment, the distal article of the maxillary palp moderately and evenly pigmented, penultimate article with moderate pigment overall but more intense distally, second and third articles with pigment dorsally, also stronger distally. Labial palp ultimate and penultimate articles overall light to dark pigment, second article darker, especially distally. Nota and thoracic sterna without obvious pigment. Precoxa of legs with darker brown pigment, which also occurs on the shoulder of the coxa but not along the outer margin. Trochanter with pigment along posterior margin. Femora fairly evenly pigmented, tending to darker at the posterior bulge and the anterior distal corners. Tibia darkly pigmented overall. First tarsal article with more pigment distally, remaining articles with some light pigment. Abdominal segments quite dark (sclerotized or pigment?) becoming darker in the posterior segments; coxites IX quite dark. Ovipositor well pigmented brown basally with pigment absent from distal four divisions. Cerci and median filament annulated, mostly dark divisions except for first annulus which is light in colouring and apex of distal division distad of the ring of macrochaetae. Abdominal styli light basally with orange pigment in distal half becoming more intense distally, styli VIII the same or sometimes with much less pigment.

Macrochaetae: Variable, subtly pectinate, curved and tapered ( Fig. 4 ), strongly pectinate ( Fig. 5 ), carrot-shaped and strongly pectinate ( Fig. 6 ), dark brown to straw coloured.

Scales: With numerous sub-parallel ribs that do not surpass the margin of the scale ( Fig. 7 ), those dorsal are brown, those ventral brown or hyaline. Scales found on top of head, on pedicel and scape, mandible, on second and third articles of maxillary palp, all nota, all thoracic sterna, legs (except for trochanter and distal three articles of tarsi), all urotergites and urosternites, styli IX, medial filament and cerci. Scales of palps, styli, terminal filaments ( Figs. 8, 9 ) of variable shape, sometimes without clearly defined ribs.

Head: ( Fig. 10 ) wider than long, with 1+1 not very dense bushes of macrochaetae aligned in subparallel rows on the antero-lateral corners, with a distinct gap in chaetotaxy between these two bushes. Eyes dark chestnut in alcohol preserved material. There is a small gap behind each bush in the row of macrochaetae along the margin which extends inwards to a contiguous large peri-antennal group and its long thin trichobothrium-like seta; the marginal row continues back and up over the eyes about two macrochaetae wide. Clypeus with 1+1 very dense bushes of strongly pectinate macrochaetae as well as a few curved setae laterally; a single macrochaeta and scattered cilia medially between the bushes. Labrum also with 1+1 dense bushes but with fewer pectinate macrochaetae as well as many simple setae scattered over the face. — Antennae fairly long, scape ( Fig. 11 ) not long with a preapical ring of setae; pedicel with preapical ring of simple setae and cilia as well as setae scattered over face; first annulus/interval of flagellum with a subapical ring of simple setae; next annulus with ring of simple setae and two trichobothria; subsequent intervals with single ring of setae and cilia across the middle of the annulus and two short trichobothria per annulus; intervals of flagellum begin to subdivide from the fifth interval. About two thirds the length of the antennae the intervals are subdivided into eight annuli ( Fig. 12 ) with the most distal annulus bearing a proximal ring of setae and a subapical ring of cilia and a trichobothrium; rod-like basiconic sensilla (type B) seen on fourth and ultimate annuli. Further distally the intervals are divided into ten annuli but trichobothria were no longer observed (lost?), basiconic sensilla seen on fifth and ultimate annuli; poculiform sensilla were seen clearly in at least two specimens (NMV T-22589, K.261324) in the very distal annuli but were not seen with confidence in other specimens, which could possibly be explained if these sensilla were only present in the most distal articles on more or less intact antennae or perhaps the sensilla were obscured by the very dark integument and unfortunate orientation. — Mandibles ( Fig. 13 ) typical for Acrotelsella with well-developed molar and incisor areas; a group of about 10–15 strong apically bifurcated but simple setae distally adjacent to the pectinate molar area and a bush of around seventy strong, pectinate macrochaetae externally as well as scattered simple setae. — Maxilla ( Fig. 14 ) with two or three thick minutely apically bifurcated and slightly pectinate macrochaetae as well as 2–6 smaller setae externally proximal to the palp, the lacinia with three strong teeth, one set further back than the other two, followed by about seven lamellate processes and a row of 5–7 short simple setae, galea longer than lacinia with about 3–5 strong, smooth, simple or apically bifurcate setae externally in its basal half and several cilia distally; maxillary palp very long and thin, apical article 4.8–6.2 times longer than wide and 1.0–1.3 times as long as the penultimate article which is the longest article, the ultimate article with a thick sausage-shaped sensillum subapically (thin-walled basiconic sensillum type C of Adel, 1984), last two articles of palp with fine setae only, third article with some slightly stronger setae subapically, second and third articles also with scales, although these can be hard to find on the third article. — Labium ( Fig. 15 ) short and broad, postmentum with transverse row of apically bifurcate setae, a few laterally with distinct pectinations, prementum with transverse and oblique rows of strong apically bifurcated setae, apically with long curved setulae; labial palp short, apical article not expanded medially, about as long as wide (0.8–1.31) with row of seven papillae of compact type arranged in a single curved row near the outer margin, with a single very small rod-like basiconic sensillum (type B) on the outer margin, covered with numerous fine setae as well as longer fine setae.

Thorax: Pronotum ( Fig. 16 ) with dense setal collar of both longer and shorter strongly pectinate macrochaetae, about three macrochaetae wide, without slight medial gap; lateral margins with many strong, shorter and longer, curved, slightly pectinate macrochaetae as well as a few cilia, with 6–8 combs of 1–3 macrochaetae along each margin. Two open trichobothrial areas; the anterior trichobothrial area ( Fig. 17 ) is slightly forward of the midpoint (0.43–0.49) and associated with comb N-2 (rarely N-3), the comb composed of only a single macrochaeta with the trichobothrium between the macrochaeta and the margin and a cilium laterad of the trichobothrium; the posterior trichobothrial area ( Fig. 18 ) is located about 0.71–0.82 of the distance along the margin and is associated with the last comb (N), this comb composed of three macrochaetae (rarely two) with the short trichobothrium at the mediad end and a cilium at the laterad end; all combs associated with a few setulae, sometimes quite numerous. Posterior margin of all nota with 1+1 combs of 3–7 macrochaetae insertions associated with several setulae between the comb and the margin and a cilium at each end, the macrochaetae are mostly lost but in several specimens (probably all) the most laterad or second most laterad is occupied by a long thin trichobothrium-like macrochaeta ( Fig. 19 ); these combs not particularly widely spaced (gap between them 50–54% of total width of pronotum). — Mesonotum ( Fig. 20 ) with lateral chaetotaxy similar to pronotum with 9–10 combs of 1–3 (rarely four) macrochaetae, the anterior trichobothrial area located 0.59–0.70 along the lateral margin, associated with comb N-2 composed of one macrochaeta (occasionally two) with the trichobothrium located between the macrochaeta and the margin, with a few setulae posterior to the comb and a cilium between the trichobothrium and the margin. (33) base of cerci and medial filament; (34) ♂ (K.261325) coxites IX and penis. Scale bars = 0.1 mm.

Posterior trichobothrial area slightly more posterior than that on the pronotum (0.80–0.85), the trichobothrium located mediad to the comb usually of three macrochaetae (sometimes fewer) and with 1–3 setulae or stronger setae posterior to the comb.— Metanotum ( Fig. 21 ) similar to mesonotum with 6–9 combs of 1–3 macrochaetae, the anterior trichobothrial area associated with comb N-1 of one or two macrochaetae about 0.70–0.78 the distance along the margin, the trichobothrium located between the margin and the macrochaeta, the posterior trichobothrial area associated with the most posterior comb (0.81–0.89 along the margin) of 2–3 macrochaetae.

Presternum narrow, with transverse row of spaced pectinate macrochaetae with numerous fine setulae below and between these macrochaetae ( Fig. 22 ). — Prothoracic sternum ( Fig. 22 ) parabolic, about as long as wide at its base (L/ W 0.86 –1.00), antero-lateral corners with about 20 simple marginal setae, posterior three quarters of lateral margins with fringe of setae and some cilia as well as 5–12 short combs on each side each composed of 1–6 short pectinate macrochaetae, combs sometimes lying quite close to each other and lying in two overlapping rows, often with a strong seta on the margin near the end of the comb but not counted in the number of macrochaetae per comb, these strong marginal or submarginal smooth macrochaetae also present distally and at irregular locations along the lateral margins. — Mesosternum ( Fig. 23 ) only a little larger than prosternum (1.1–1.2 times as long) about as long as wide at its base (L/ W 0.96 –1.13), anterolateral corners glabrous, posterior third of margins with many long thin setae and cilia and 3–4 combs on each side distally, the more anterior composed of 5–10 pectinate macrochaetae and the more posterior composed of 1–4 pectinate macrochaetae; all combs with several curved setulae beneath them, larger smooth, tapered macrochaetae distally at or past the level of the more distal combs. — Metasternum ( Fig. 24 ) of similar length to prosternum except wider (L/ W 0.78 –0.87), apically rounded, with marginal setae and cilia along distal ¼ of lateral margins and 3+3 (occasionally two or four) combs of 1–9 pectinate macrochaetae.

Legs quite long, tibia L/W ratio of PI 2.1–3.2, PII 2.7–3.5, PIII3.6–4.3; tarsi L/W ratio PI 5.1–7.5, PII range 7.4–8.3, PIII 8.9–11.3. PI ( Fig. 22 ) with a comb of 3–8 pectinate macrochaetae laterally on the distal margin of the precoxa. Coxa with scales and a group of about 6–9 macrochaetae on the anterolateral corners usually arranged in two close rows, followed by a field of strong pectinate macrochaetae along the external margin about two the three macrochaetae wide, the margin with curved slightly pectinate macrochaetae, the macrochaetae behind the margin pectinate and usually grouped into combs of two or three; inner margin with a four lightly pectinate macrochaetae and several smooth and delicately pectinate setae of varying thickness distally over the articulation. Trochanter with a small pectinate macrochaeta and several setae, cilia and setulae. Femur posteriorly with a long thin pectinate macrochaeta nine tapered or slightly carrot-shaped pectinate macrochaetae along the posterior margin and a line of smooth setae posteriorly, dorsal margin with at least three short curved pectinate macrochaetae over the articulation. Tibia of PI with six (?) stout, carrot-shaped, mildly pectinate macrochaetae along the ventral margin as well as several longer, thinner, smooth setae and a row of shorter setae near the distal margin; anterior margin with two pectinate macrochaetae and a stronger seta near the distal margin, dorsal margin with two short, curved, mildly pectinate macrochaetae spaced along the margin and a few smooth setae subdistally, with usual tibial spur bearing a few setae. Tarsi with four articles, the basal article of PI about half the total length of the tarsus, its join with the next article not particularly oblique, the surface of all tarsal articles with numerous simple setae, those ventral near the distal end of the basal three articles more robust and with more rounded tips. On some specimens a raised oval area is visible on the second tarsal article. Pretarsus with two long curved lateral claws and a shorter curved medial claw. PII and PIII ( Figs. 25, 24 ) similar to PI except the antero-lateral groups of macrochaetae on the coxa absent; legs progressively longer from PI to PIII (L tibia PI/PIII 0.51–0.73, L tarsus PI/PIII 0.58–0.67 and the relative length of the basal tarsal article is progressively longer, being about 0.6 of the total length on PIII.

Abdomen: Urotergite I with 1+1 lateral combs of 4–6 macrochaetae each associated with a cilium at both ends, and 2–3 small marginal setae and several setulae between the comb and the margin, urotergites II–VII with 3+3 combs of macrochaetae as in Table 3 ( Fig. 26 ), the lateral combs with two cilia as well as 2–4 small marginal setae 3–8 setulae, the sublateral combs with a cilium at the mediad end as well as 2–3 small marginal setae and 2–5 setulae, the submedial combs with a cilium at the laterad end as well as 2–5 small marginal setae and 4–6 setulae; urotergite VIII with 2+2 combs (lacking the sublateral), also with a cilium at each end of both combs as well as 2–4 marginal setae and 5–6 setulae, urotergite IX glabrous except for a single marginal seta in the infralateral position ( Fig. 27 ) on some specimens, it is present on one side only of the holotype, both sides in NMV T-22589, K.261324, K.541623 and K.261325 but absent in K.541622, K.261284, NMV T-22588 and K.541624. — Urotergite X ( Fig. 28 ) equilateral triangle (64–86°), wider at base than long (L/ W 0.43 –0.62) with many long fine pectinate tapered setae along entire margin, and (3–4)+(3–4) combs of 1–7 macrochaetae per comb (all lost) as well as a few setulae posterior to each comb, and most combs with a cilium at the mediad end.

Urosternite I and II glabrous, urosternites III–VII with 1+1 lateral combs of 10–23 pectinate macrochaetae ( Figs. 29, 30 ) each with several marginal setae and several setulae between the comb and the margin as well as a cilium at the laterad end of every comb (occasionally not present). The distance between the lateral combs 1.7–4.8 times the average width of these combs, the ratio being largest on urosternite III and decreasing posteriorly.

Genital region of ♀ as in Figure 31 . Two pairs of styli, those on IX long and slender with robust setae apically and along the length of the stylus, styli of VIII similar and not much smaller. Coxites VIII with long combs of 17–23 macrochaetae and about half this number of marginal setae and a few setae in between the two, the coxites with straight truncate posterior margin and a slightly obtuse angle with the inner margin, the corner being moderately rounded the curve occupying only ⅐ to ¼ the length of the posterior margin. Each coxite IX with long internal process which is quite broad, about 1.6–2.8 times longer than wide at its base and 5.4–7.6 times longer than the short pointed external process, the inner processes not quite reaching the apex of the ovipositor; outer process with stout setae along the outer margin, inner process with numerous, quite long, closely packed setae along the outer margin adjacent to the stylus, a long smooth macrochaetae inserted mediad of the base of the stylus, the inner margin with 5–7 combs of 1–5 pectinate macrochaetae. — Ovipositor ( Fig. 31 ) not very long (1.1–1.4 HW), of secondary type, only just surpassing the apex of the long internal processes of coxites IX, both pairs of gonapophyses consisting of longer basal divisions becoming progressively shorter distally except for the last divisions which are about as long as the previous two or three together, 11–15 divisions in total; the apical seven divisions armed with modified spines or conules which become more numerous distally, the last divisions with 7–10 modified spines ( Fig. 32 ); all divisions also with short fine trichobothria-like setae.

Cerci ( Fig. 33 ) first division almost glabrous except for single small seta externally, second division with sub-basal semi ring of a few small setae and a medial ring of setae, a trichobothrium and a pectinate macrochaeta externally, third division with a single ring of setae, trichobothria and some pectinate macrochaetae towards the outer margin, fourth interval similar but also with basal semi-ring of scales and a trichobothria and the subapical ring also contains some cilia, fifth division similar although it is uncertain whether the basal ring is of small setae or scales, sixth and seventh divisions with basal ring of setae and trichobothria followed by a semi-ring of scales then a subapical ring of setae, macrochaetae, cilia and some trichobothria, eighth and ninth divisions with four rings the most basal and third probably mostly of scales but also a small trichobothrium and a small seta respectively; subsequent divisions lost from holotype. — Median dorsal appendage, first division with only a couple of long thin delicately pectinate setae near the outer margins, following three divisions with single rings of long thin setae and trichobothria, divisions 5–7 with two rings, the more basal with a small trichobothrium some setae and some scales, the subapical ring with setae, trichobothria, cilia and macrochaetae, following division with an additional ring of scales between the sub-basal and subapical rings, ninth similar but with an additional ring of scales basally.

Male: Similar to female except urosternite VIII entire with posterior margin between the combs slightly concave. Coxites IX in ♂ separated ( Fig. 34 ) with internal process broad and much shorter than that of the female being only 1.0–1.1 times longer than wide at its base and 2.8–3.9 times longer than the short pointed external process, the inner processes not quite reaching to half the length of the stylus; outer process with stout setae along the outer margin, inner process with setae along both margins, as well as 3–4 submarginal combs of 1–4 macrochaetae along the inner margin, as well as a long smooth macrochaetae inserted mediad of the base of the stylus. Penis typical with numerous glandular setae apically, each set on a protuberance. Parameres absent.

Habitat. This species was mostly collected in dry leaf litter.

Etymology. The species is named mallee which is the vegetation type predominant in much of the habitat of this species in south-western NSW and north-western Victoria. It is treated as a noun.

Remarks

As indicated above, both morphology and molecular data, which also includes several further undescribed species, suggest that species with a secondary ovipositor may form a separate clade from the rest of the genus Acrotelsella . However more taxonomic work is required before this question can be resolved.

Given the weak descriptions of many older species it is difficult to be certain of the position of A. mallee sp. nov. relative to other species which appear to have a secondary type ovipositor. It differs from A. annamita Silvestri, 1948 because the Vietnamese species lacks transverse combs on coxites IX. Furthermore A. annamita has three pairs of styli versus two in mallee and the spines on the ovipositor are restricted to the last division in A. annamita . The inner processes of coxites VIII of female in A. annamita are more rounded and obtuse compared to truncate and straight in A. mallee sp. nov. Urotergite X appears to be more elongate in annamita and the anterior trichobothrial area of pronotum much further forward on annamita (0.32 versus 0.43–0.49). Acrotelsella mallee sp. nov. has (3–4)+(3–4) combs on the mesosternum and 3+3 combs on metanotum whereas A. annamita has only 2+2 and 1+1 combs respectively. Acrotelsella annamita has five labial palp papillae versus seven in mallee .

Acrotelsella impudica ( Escherich, 1905) also has a secondary ovipositor but the modified spines are unusually tapered and curved compared to the Australian Acrotelsella species and Escherich’s species has short curved inner processes on both coxites VIII and IX. However, A. impudica sensu Wygodzinsky, 1959 lacks the curved coxites IX but they are still quite short, and the inner processes of coxites VIII are curved and resemble the more usual Acrotelsella shape and it has five labial palp papillae. This species needs to be redescribed.

Although the description of A. devriesiana Silvestri, 1908 is far from complete by today’s standards, it also has a secondary type ovipositor and coxites VIII are of similar shape. It clearly differs from A. mallee sp. nov. in having only 1+1 combs on the metathoracic sternum (versus 3+3) and urotergite X appears to be more acute (56° versus 64–86°). It also appears to lack transverse combs on the inner margin of coxites IX whereas A. mallee sp. nov. has 3–7 combs each of 1–5 macrochaetae. The specimens Silvestri mentions from Dongarra probably should not be included with A. devriesiana as the ovipositor is much longer than the coxites and it lacks styli on coxites VIII. The subspecies perspinata is also clearly different because it has only 2+2 combs on the metasternum, 2+2 lateral combs on coxites IX and a long line of 12 papillae on the labial palp.

Acrotelsella devriesiana westralis (Nicholls & Richardson, 1926) is inadequately described with no details of the female however it probably belongs in this group. It also has 3+3 combs on both the thoracic meso- and metasterna and has transverse combs on coxites IX of the male however it appears to have an unusual arrangement of five labial palp papillae in a circular group. More material is required to investigate these issues. With evolving understanding of the species limits in Acrotelsella , this subspecies should probably be considered as a full species, as initially proposed by its describers.

Acrotelsella silvestri Womersley, 1939 may or may not fit into this group. It has spines on the ovipositor but they appear to be completely different to those of other species in being scale like. It is not clear from the illustration whether there are combs on the inner processes of coxites IX but they are quite short. Too many other characters have not been included in the description for further comment.

Figures

Figure 2. Known distribution of Acrotelsella mallee sp. nov. and a closely related taxon.

Figure 3. Acrotelsella mallee sp. nov., Balranald, NSW.

Figures 4–15. Acrotelsella mallee sp. nov. holotype ♀ unless otherwise indicated by specimen number (4) long pectinate macrochaeta of coxa of PI; (5) pectinate macrochaeta, peri-ocular; (6) carrot-shaped pectinate macrochaeta of tibia of PII; (7) darker scale from coxa of PIII; (8) and (9) scales from median dorsal appendage; (10) head (cross-hatched area obscured by eye pigment, posterior left side missing); (11) antenna, scape, pedicel and basal intervals of flagellum; (12) idem, most distal surviving complete interval; (13) mandible (K.261325);(14) maxilla (K.261324); (15) labium, smaller chaetotaxy and papillae omitted from one palp (K.261324).Scale bars = 0.1 mm.

Figures 16–22. Acrotelsella mallee sp. nov. holotype ♀ (16) pronotum, right side; (17) left anterior trichobothrial area of pronotum; (18) left posterior trichobothrial area of pronotum; (19) left posterior comb of pronotum; (20) mesonotum, right side; (21) metanotum, right side; (22) prothoracic presternum, sternum and PI. Scale bars = 0.1 mm.

Figures 23–27. Acrotelsella mallee sp. nov. holotype ♀ (23) mesothoracic sternum; (24) metathoracic sternum and PIII; (25) PII; (26) urotergite III; (27) urotergite IX, right infralateral seta. Scale bars = 0.1 mm.

Figures 28–32. Acrotelsella mallee sp. nov. holotype ♀ (28) urotergite X; (29) urosternite IV; (30) urosternite VII, detail of right comb; (31) coxites VIII and IX with ovipositor; (32) apex of gonapophyses. Scale bars = 0.1 mm.

Figures 33–34. Acrotelsella mallee sp. nov. holotype ♀ unless otherwise indicated by specimen number