Monographis queenslandicus, Huynh, Cuong & Veenstra, Anneke, 2013

Huynh, Cuong & Veenstra, Anneke, 2013, Taxonomy and biology of a new species of Pincushion Millipede of the genus Monographis (Diplopoda: Polyxenidae) from Australia, Zootaxa 3721 (6), pp. 573-588 : 576-587

Monographis queenslandicus sp. n.

Holotype. Male collected on 20 July 2011 from Boondall Wetlands Park, north east Brisbane, Queensland, Australia (27020′24.56 ″S, 15304′40.19 ″E). (Queensland Museum registered number: QMS 95885)

TABLE 1. Genus Monographis can be divided into 2 groups based on the arrangement of sensilla on the 6th antennal article. Group 1 has a crescent shape; Group 2 has a triangular shaped of sensilla arrangement of sensilla.

Paratypes. Five males (QMS 95886, 95887, 95888, 95889, 95890), five females (QMS 95891, 95892, 95893, 95894, 95895) and five of each immature stadium were mounted on slides. All mounted slides and other material, will be catalogued and lodged in the Queensland Museum, Brisbane, Queensland, Australia.

Etymology. The specific name refers to the state of Queensland, in north eastern Australia where this species was first found.

Diagnosis. This new species differs from Monographis kraepelini in having 16–19 sensilla, with 3 anterior thick sensilla, 5 internal sensilla, forming a triangular shape on the 6th antennal article. The surface of the labrum is smooth and asetose. The telotarsus bears an anterior process, with enlarged base, 0.5 times the length of the claw, a small posterior process and a small lateral process, the anterior setiform process 1.2 times longer than the claw.

Description. Measurements: Holotype male 3.0 mm long, male (paratypes) range (n = 10) 2.4–3.0 mm and females range (n = 10) 3.0– 3.4 mm. Caudal bundles of females were about 0.9mm longer than in the males (0.7mm).

Colouration: Specimens are yellowish brown, darker on each latero-posterior rosette trichomes, forming 2 dark lateral bands contrasting with a light yellow medial band across the body. Bright red in eye areas, combined with 2 black bands connecting the two regions, which makes the head distinct from the rest of the animal. The last tergite is darkest, dark shading extending into the telson region, where the caudal bundle trichomes form light silvery bands near the base. The colour of these bands gradually fades to white and reflects light to produce blacksilver colouration toward the end of the telson. The ventral side of body is white ( Figure 3 , A–C).

Head with 8 ocelli on each side: 4 located dorsally, 4 laterally (1 anterior, 2 medial and 1 posterior). Vertex with 2 posterior trichome groups, a large gap between the 2 groups, each group with 2 rows. The anterior, oblique row has a variable number of large trichome sockets in the centre, reduced in size toward both ends with a narrow space between the anterior and the posterior row, which has fewer small trichome sockets. Trichomes within these rows vary in number and arrangement between individuals. Holotype male with 16 + 14 trichome sockets (anterior row) and 4 + 4 (posterior row). Trichobothria were typically thin, funicular, cylindrical structures. All three (a, b and c) are equal in size, forming an isosceles triangle with equal distance between ab and bc ( Figure 4A ).

The clypeo-labrum, with 10 setae, is shorter in length than the width of labrum. Paratypes ranged 6–10 setae in both sexes. The surface of labrum of the holotype was smooth, without setae along the anterior margin and a line of minute setae along the posterior portion. Some paratypes had a few triangular spines on the surface of labrum. On the anterior margin, 1 + 1 lamellar plates associated with lateral lamellae on each side of the median cleft ( Figure 4 E).

Antennae typically consist of 8 articles and four sensory cones (Figures 5A–G). The 6th antennal article (Figures 5D & F) has 16–19 bacilliform sensilla in males and 16–18 bacilliform sensilla in females. The holotype has 18 sensilla, including 3 thick bacilliform sensilla, a conical sensillum, a setiform sensillum and 15 -16 thin bacilliform sensilla. The typical 3 thick bacilliform sensilla: anterior a (Tbs a), intermediate i (Tbs i) and posterior p (Tbs p) are located on the anterior portion, 1 conical sensillum (c), 13–14 thin bacilliform sensilla (tbs) and 1 setiform sensillum (s) forming a triangular shape surrounding 5 thin bacilliform sensilla (*) to form an inner group. The arrangement of these 5 thin bacilliform sensilla on the 6th article is a taxonomic character used to define this species. The position of conical sensillum varies amongst individuals. Sometimes it is located next to the thick bacilliform p; others are behind one of the thin bacilliform sensillum. This also occurs with 3 thick sensilla where sometimes there are 1, 2 or up to 3 thin sensilla between them. Once again, these patterns varied with individuals. The 7th antennal article has 2 thick bacilliform sensilla (Tbs), the anterior one slightly longer than the posterior, with one setiform sensillum (s) between them and a conical sensillum (c) located in the posterior position (Figure 5E). This pattern of sensilla on the 7th article is commonly seen in all species of Monographis (Nguyen Duy- Jacquemin & Condé 1967).

Lateral palp of gnathochilarium 1.25 times the length of medial palp. Lateral palp with 11 conical sensilla and medial palp with 22 slender conical sensilla ( Figure 4 F).

Trunk consists of 10 segments, 9 pleural projections, excluding the telson and caudal bundle; 13 pairs of legs. Collum is the only tergite with lateral protuberances bearing 3–6 trichomes on each side. All other tergites have a pair of pleural projections located antero-laterally. Tergal trichome arrangements typically have 2 broad oval shapes, slightly enlarged laterally, connected with a posterior row slightly curved up toward the centre with a large gap between these trichomes. Collum considered as tergite 1 (smallest tergite) with 55 (Left: L), 63 (Right: R) trichome sockets and 4(L) / 4(R) in lateral protuberance on holotype ( Figure 4 B). Numbers varied in paratype males, range 46–63; and paratype females, range 47–60 trichomes. Tergite 2 has the same structural pattern with posterior row slightly longer and with 55(L)/55(R) trichomes ( Figure 4 C). For tergites 3–9, patterns remained very similar with the characteristic large gaps. Tergite 10 is an exception where the trichome sockets of this segment are smaller and denser. There is almost no space between the lateral rosette trichome groups and the posterior row ( Figure 4 D).

FIGURE 5. A. Head capsule and antennae of Monographis queenslandicus sp. n., B. 6th, 7th & 8th antennal article, C. 7th & 8th antennal article, D. 6th antennal article. E. Arrangement sensilla on 7th antennal article, F. Arrangement of sensilla of 6th article, showing position of 3 thick bacilliform sensilla (Tbs) anterior a, intermediate i and posterior p; 5 thin bacilliform sensilla (*); a conical sensillum (c) and setiform sensillum (s), G. Left side antenna and its articles.

Legs: Legs 1 and 2 are without trochanter, leg 1 also lacks tarsus 1. Chaetotaxy as follows: coxa 1: 2 sensilla, coxa 2: 2 sensilla, coxae 3–13: 1–4 sensilla; all pre-femurs, post-femurs, tibia with 1 sensilla, except femurs with 2–4 sensilla, tarsus 1 and tarsus 2 with a spine ( Figure 4 H). Coxa, pre-femur and femur, are with a ridged biarticulate, funicular cylindrical sensillum ( Figure 4 L). There were also 2–3 smaller biarticulate funicular cylindrical sensillum present on the posterior end of the femur ( Figure 4 M). At their distal edge, post-femur and tibia with a setiform sensillum ( Figure 4 K). Spine on tarsus 2, much larger and sharp ( Figure 4 I), compared to a spine on antero-sternal position of tarsus 1 ( Figures 4 J & N). Two to four ridged biarticulate, funicular cylindrical sensilla were found on posterior edge of the last sternite. These sensilla were similar to those present on the coxa. The number of sensilla varied, 2 present on holotype male ( Figure 4 G) and 2–4 on paratypes.

Telotarsus (claw): slender structure; composed of an anterior process, with enlarged base, almost 0.5 times shorter than the claw. A tiny lateral process and a small posterior process present. The setiform process is slightly longer than the claw; lamella process present ( Figure 4 O).

Sex organs in male: A pair of penises on the 2nd coxa and 2 pairs of coxal glands on coxal plates of 8th and 9th legs.

Telson: Dorsal ornamental trichomes arranged almost symmetrically on each side with 14 trichomes a in holotype male ( Figure 6A ). Paratypes with 10–17 trichomes a in both sexes. Trichomes a formed 2 rows, top row with small trichomes and bottom row with larger trichome sockets. Two largest sockets situated near trichome b. Three large protruding basal trichomes c: c1, c2 and c3, form a triangular shape. Circular indentation d apparent near exterior side of trichomes c ( Figures 6A , L & M).

Structure of caudal bundles in males and females. Caudal bundles differed in appearance in males and females of Monographis queenslandicus sp. n.. In males, the caudal bundle was uniform in structure with similar size trichome sockets ( Figures 6 B, C & F). Caudal trichomes had 2–4 hooks, commonly 2–3 hooks, facing ventrally. Hooks connected with distal facing, small barbate in middle section and joining with larger barbate stem forming 3–4 rings of 3 spines, facing distally at the base of this trichome stem ( Figure 6 K). Few larger barbate trichome sockets present, commonly 2–3 rows, forming slightly uneven lateral rows, extending toward the centre of the telson. Barbate trichomes large with the length exceeding the longest caudal trichomes in the bundle, which are used to prevent the hooks on trichomes tangling ( Figure 6 N). In females, caudal trichomes differed with two distinguishing structures. The main dorsal structure was similar to the male caudal bundle and 2 latero-sternal bundles ( Figures 6 D, E & G). These latero-sternal bundles had small, fine trichome sockets with trichomes 0.5 shorter than those on main caudal trichomes. Lateral trichomes differed from caudal trichomes by having smaller, slender stems with double facing spines connected with 3–5 hooks. These were usually lost when building a nest for egg clusters (we consider these to be nesting trichomes) ( Figure 6 J).

Additional specimens A brief overview of the sub-adult stadia: I, II, III, IX, V, VI, and VII (3, 4, 5, 6, 8, 10 and 12 pairs of legs) in the life cycle of Monographis queenslandicus sp. n.: The newly hatched pincushion millipedes initially had 5 ocelli and 5 segmented antennal articles, these numbers increased into 6 ocelli and 7 antennal articles in stadium III (5 leg pairs stage). Two new ocelli developed to form 8 in stadium VI (6 leg pairs stage). By stadium V (8 leg pairs stage), with 8 ocelli and 8 antennal articles, millipedes were almost fully developed adults. These characteristics remained unchanged to adulthood. The development patterns of antennal articles of M. queenslandicus sp. n. were similar to the patterns found in study of Polyxenus lagurus (Nguyen Duy- Jacquemin 1972); the ocelli pattern in the developmental stages of M. queenslandicus sp. n. is summarised in Figure 7 . All morphological characteristics of sub-adult stages were very similar to the adult form.

Stadium VII, 12 pairs of legs. Measurements: Body length (n = 5, for each sex), males measured 1.8–1.9 mm and females 1.8–2.0 mm, caudal bundle 0.6 mm in both sexes.

Colouration: Colour pattern as seen in adult but lighter in colour.

Head with 8 ocelli of equal size. Posterior vertex with 2 groups, similar arrangement to adult, anterior and posterior rows, had 11–14 and 3–5 trichome sockets in males, 12–15 and 2–7 trichome sockets in females. Three trichobothria are typical; 8 antennal segments with 4 sensory cones, 6th antennal article, with 15–17 bacilliform sensilla in males and 14–16 in females, these included 3 thick bacilliform sensilla and 3–4 internal bacilliform sensilla, forming a triangular shape (Table 2). The 7th article had 2 thick bacilliform sensilla, a setiform sensillum in between these two, and conical sensillum located posteriorly. Clypeo-labrum with 8–10 setae in both sexes, a line of minute setae along posterior margin, surface of labrum smooth and typically 2 lamellae associated with lateral lamellae on each side of median cleft. The lateral palp of gnathochilarium, as in adults, was almost 1.25 times the length of medial palp. Lateral palp with 11 and medial palp with 22 slender conical sensilla.

Trunk included 9 segments, 8 pairs of pleural projections, excluding telson and caudal bundle. Arrangement of tergal trichomes was similar to the adults. Number of trichome sockets of collum 37–48 in males and 36–50 in females. Tergite 2 with 42–49 trichome sockets in males and 41–51 in females. Lateral protuberance, in both sexes, with 3–6 trichome sockets on each.

Legs: Chaetotaxy as follows: coxa 1 = 1–2 sensilla, coxa 2 = 2 sensilla, coxae 3–10 = 2–3 sensilla. All prefemurs, post-femurs, tibia with a single sensillum. Tarsus 1 and tarsus 2 with a spine. Exception was femur of leg 1 with 1 sensillum, leg 2 with 2 sensilla and remainder to 10th leg with 2–4 sensilla. 11th and 12th leg, were asetose on coxa, post-femura, tibia. Tarsus 1 lacked a spine. Typically the spine was comparatively large and strong on tarsus 2.

Telotarsus: as in adult, claw with a large, strong base anterior process, a tiny lateral process and a weak posterior process, a long anterior setiform process and a common lamellar process.

Telson: 14–17 dorsal ornamental trichomes, in males and 12–18 trichomes a in females, almost the same as adult, 1 trichome b, 3 trichomes c and circular indentation d. Caudal bundle, the same in males and females, unified with medium size sockets, with few larger barbate trichome sockets forming uneven rows laterally toward the centre. Two clusters of large trichome sockets, resembling those on pleural projections with shorter barbate trichomes, located in latero-sternal position. A new pair of pleural projections formed after moulting. The caudal trichomes were similar to adult form with 2–4 hooks.

Sex organs, penises or vulva located on the coxal plates of the second legs, coxal glands on 8th–9th legs, were fully developed in this stage.

Remarks. In this stadium, Monographis queenslandicus sp. n. had very similar characteristics to the adult form, with no difference between males and females. The numbers of bacilliform sensilla, 14–17, on the 6th article were almost the same as the adult form (16–19). The main differences were 3–4 internal bacilliform sensilla, instead of 5 sensilla in adult. Legs 11–12 lacked sensilla on coxa, post-femur, tibia and tarsus 1. Caudal bundle uniform in size of trichome sockets and two sterno-lateral undeveloped pleural projections. There were no nest trichomes apparent in this stadium. The sex organs were completely developed.

Stadium VI, 10 pairs of legs. Measurements: Body length (n = 5) 1.5–1.8 mm and caudal bundle 0.6 mm in both sexes.

Colouration: Lighter in colour, body is yellowish, in contrast to light dark rosette trichomes and silvery caudal bundle of trichomes. Eye regions bright red connected by dark bands.

Head with 8 ocelli on each side. The dorso–anterior ocellus was slightly smaller than other ocelli. There was no difference in the number characters between sexes in this stadium, posterior vertex with 2 groups, anterior and posterior rows, 10–13 and 2–4 trichome sockets. Three trichobothria were typical. Eight antennal articles with 4 sensory cones; the 6th article with a conical sensillum, a setiform sensillum and 14–15 bacilliform sensilla, including 3 thick and 3 internal bacilliform sensilla forming a triangular shape (Table 2). Two bacilliform sensilla, a setiform sensillum and a conical sensillum were usual in the 7th article. Clypeo-labrum with 8–10 setae, posterior margin with a line of minute setae; surface of labrum smooth and structure as seen in adults. The lateral palp of gnathochilarium was almost equal in diameter to medial palp; 9 slender conical sensilla on lateral palp and 20 on medial palp.

Trunk with 8 segments, 7 pleural projections, excluding the telson and caudal bundle. 10 pairs of legs. The arrangement of tergal trichomes was similar to adults, the number of trichome sockets of collum 32–44. Tergite 2 had 26–42. Lateral protuberances had 3–5 trichome sockets on each side. Legs: Chaetotaxy as follows: coxa 1 with 1 sensillum, coxa 2 with 1–2, coxae 3–8 with 2–3. All pre-femurs, post-femurs, tibia with a sensillum. Tarsus 1 and tarsus 2 with 1 spine. An exception was the femur of leg 1 with 1 sensillum, leg 2 with 2 sensilla and the rest to the 10th leg with 2 sensilla. The 9th and 10th legs with asetose coxa, post-femurs, tibia and tarsus 1 lacked a spine. A typical spine was large and strong on tarsus 2.

Telotarsus: similar to adult.

Telson: Number of dorsal ornamental trichomes a, 14–18, almost the same as adult, 1 trichome b and 3 trichomes c, circular indentation d was not visible. Caudal bundle had the same structure as stadium VII; caudal trichomes with 2–4 hooks and nest trichomes absent.

Sex organs, vulva, penises and coxal glands are developing in this stage.

TABLE 2. Developmental stages of Monographis queenslandicus sp. n. with corresponding sensilla patterns on the 6th antennal article indicated.

Remarks. In this stadium, body with 8 segments, associated 7 pleurals, slightly different to arrangement of the 6th antennal article, number of bacilliform sensilla decreased and 3 bacilliform sensilla present in internal row only. One ocellus smaller than other ocelli. The 9th–10th legs were asetose on coxae, post–femora, tibiae and tarsus 1. Caudal bundle was typical in sub-adult stage. Sex organs developed.

Stadium V, 8 pairs of legs. Measurements: Body length 1.2–1.4 mm (n = 5), caudal bundle measured 0.5 mm.

Colouration: Colour pattern similar to adult, but lighter.

Head with 8 ocelli. 2 dorsal ocelli, one located antero-internal and other on postero-internal position, smaller in size than those seen in adults. Two posterior vertex groups, anterior and posterior rows, fewer in number, 9–12 and 2–4 trichome sockets only; 3 trichobothria present. Eight antennal articles with 4 sensory cones, the 6th article with a conical sensillum, a setiform sensillum and 13 bacilliform sensilla, typically 3 thick sensilla and the internal row of 3 bacilliform sensilla, forming a slightly triangular shape (Table 2). The 7th article had 2 bacilliform sensilla, 1 setiform in middle, conical sensillum posteriorly. Clypeo-labrum with 8 setae only, labrum structure resembled stadium VI. Gnathochilarium with 9 on lateral palp and 20 slender conical sensilla on medial palp on each side.

Trunk included 7 segments, 6 pleural projections, excluding caudal bundle, 8 pairs of legs. The arrangement of tergal trichomes similar to adults, but less dense, trichome sockets of collum = 30–32. Tergite 2 with 32–34. Lateral protuberance with 3–5 trichome sockets on each side. Legs: Chaetotaxy as follows: coxae 1 and 2 = 1 sensillum, coxae 3–6 = 2. Pre-femurs, femurs, with 1 seta; tarsus 1 and tarsus 2 with spines, post-femur and tibia lacked sensilla. Coxae, post-femurs, tibia and tarsus of leg 7 and 8 lacked sensilla and spines. A typically strong spine present on tarsus 2.

Telotarsus was similar to adult.

Telson: Number of dorsal ornamental trichomes a with 12–15, 1 trichome b and 3 trichomes c. Circular indentation d was absent. Caudal bundle with the same structure as sub-adult stage. Caudal trichomes with 2–4 hooks.

Sex organs slightly developed, but difficult to discern in at this stage.

Remarks. In this stadium, body with 7 segments, 6 pleurals associated. Some changes in number of sensilla on the 6th article; there were 13 bacilliform sensilla including 3 internal bacilliform sensilla. Two ocelli appeared smaller than others. The 7th and 8th legs were asetose on coxae, post–femurs, tibia and tarsus 1. Caudal bundle typical in sub-adult stage. Sex organs slightly developed.

Stadium IV, 6 pairs of legs. Measurements: Body length 1.1–1.3 mm (n = 5), caudal bundle measured 0.5 mm.

Colouration: As in adult, but lighter.

Head with 8 ocelli, with 1 small dorsal ocellus located postero-internal, 1 smaller ocellus in antero-internal position and one small ocellus in latero-anterior position. Two posterior vertex trichome groups with fewer trichome sockets, anterior rows with 9 and posterior rows with 2–5 trichome sockets. Three trichobothria present. There were only 7 antennal articles and 4 sensory cones. The 6th antennal article with a conical sensillum, a setiform sensillum and 11 bacilliform sensilla, typically 3 thick sensilla and internal row of 2 bacilliform sensilla forming a crescent shape (Table 2). The 7th article with 2 bacilliform sensilla, 1 setiform in middle, a conical sensillum posterior. Clypeo-labrum with 8 setae, labrum structure resembled stadium VII. Gnathochilarium with 9 conical sensilla on lateral palp and 20 slender, conical sensilla on medial palp on each side. Body included 6 segments, 5 pleural projections, excluding telson and caudal bundle; 6 pairs of legs. The arrangement of tergal trichomes was similar to adult, but less dense; collum with 32 trichome sockets. Tergite 2 with 36 trichomes sockets. Lateral protuberances had 3 trichomes sockets on each side. Legs: Chaetotaxy as follows: coxae 1–4 with 1 sensillum, pre-femurs, femurs and tarsus 2 with 1 sensillum, post-femurs, tibia and tarsus 1 were asetose. Coxae, post-femurs, tibia and tarsus 1 of the 7th and 8th legs were also asetose. A typically strong spine present on tarsus 2.

Telotarsus similar to adult.

Telson: 8–9 dorsal ornamental trichomes a, 1 trichome b and 3 trichomes c. Caudal bundle had the same structure as sub-adult stage. Caudal trichomes with 2–4 hooks.

Sex organs were undeveloped.

Remarks. In this stadium, body with 6 segments, associated 5 pleurals, 6 pairs of legs, with a varying number of sensilla on the 6th article; 11 bacilliform sensilla including 3 internal bacilliform sensilla. Three additional ocelli appeared, 1 fully developed and 2 newly formed. The 5th and 6th legs were asetose on coxae, post- femurs, tibia and tarsus 1. Caudal bundle typically seen in sub-adult stage. Sex organs undeveloped.

Stadium III, 5 pairs of legs. Measurements: Body length 0.95–1.0 mm (n = 5), caudal bundle measured 0.3 mm.

Colouration: Light yellow, red in eye area.

Head with 7 ocelli, with 1 small dorsal ocellus developing in the antero-internal position and one newly established small ocellus in latero-anterior position. Two posterior vertex trichome groups were few in number; anterior row with 7–8 and posterior row with 1–2 trichome sockets. Three trichobothria present. Seven antennal articles and 4 sensory cones, the 6th article with a conical sensillum, a setiform sensillum and 10–11 bacilliform sensilla, typically 3 thick sensilla and 1 internal bacilliform sensilla, forming a slightly curved row (Table 2). The 7th article had 2 bacilliform sensilla, 1 setiform in the middle, a conical sensillum posteriorly. Clypeo-labrum with 6–8 setae, labrum structure resembled that of stadium 7. Gnathochilarium with 9 on lateral palp and 20 slender conical sensilla on medial palp on each side.

Trunk included 5 segments, 4 pleural projections, excluding telson and caudal bundle; 5 pairs of legs. The arrangement of tergal trichomes was similar to adults, but less dense, collum with 15–17 trichome sockets. Tergite 2 had 18–19 trichome sockets. Lateral protuberances with 3 trichome sockets on each side. Legs: Chaetotaxy as follows: coxae 1–4 with 1 sensillum, pre-femurs, femurs and tarsus 2 with 1 sensillum, post-femura, tibia and tarsus 1 were asetose. Coxa, post-femura, tibia and tarsus 1 of the 5th leg were asetose. A typically strong spine present on tarsus 2.

Telotarsus was similar to adult.

Telson: Number of dorsal ornamental trichomes a with 8–11, 1 trichome b and 3 trichomes c. Caudal bundle the same structure as sub-adult stage. Caudal trichomes with 2–4 hooks.

Sex organs undeveloped.

Remarks: In this stadium, body with 5 segments associated 4 pleural projections, 5 pairs of legs, with variation in the number of sensilla on the 6th article. There were 10 bacilliform sensilla including 1 internal bacilliform sensilla. Three additional ocelli present with 1 fully developed and 2 newly formed. The 5th leg was asetose on coxa, post–femur, tibia and tarsus 1. Caudal bundle typical in sub-adult stage. Sex organs were undeveloped.

Stadium II, 4 pairs of legs. Measurements: Body length 0.5–0.7 mm (n = 5), caudal bundle measured 0.25 mm.

Colouration: light yellow, red in eye area.

Head with 5 ocelli, 2 dorsal, 3 antero-laterals, medio-lateral and postero-lateral positon.

Two posterior vertex trichome groups were few in number, anterior row with 6 and posterior row with 1 trichome socket. Three trichobothria present. Five antennal articles and 4 sensory cones, the 6th article with a conical sensillum, 9 bacilliform sensilla, typically 3 thick sensilla, forming a slightly curved row (Table 2). The 7th article had 2 bacilliform sensilla, 1 setiform in middle, a conical sensillum posteriorly. Clypeo-labrum with 6 setae, labrum structure as in stadium VII. Gnathochilarium with 6 on lateral palp and about 15 slender conical sensilla on medial palps on each side.

Trunk included 4 segments, 3 pleural projections, excluding telson and caudal bundle, 4 pairs of legs. The arrangement of tergal trichomes similar to adults, but simple, 15 trichome sockets of collum were present. Tergite 2 had 17. Lateral protuberance with 2 trichome sockets on each side. Legs: Chaetotaxy as follows: coxae 1–2 with 1 sensillum, pre-femurs, femurs with 1 sensillum and tarsus 2 with a spine. Post-femurs, tibia and tarsus 1 were asetose. Coxae, post-femur, tibia and tarsus 1 of 3rd–4th lacked sensillum. A typically strong spine on tarsus 2.

Telotarsus was similar to adult.

Telson: Number of dorsal ornamental trichomes a with 5, 1 trichome b and 1 trichome c. Caudal bundle had the same structure as sub-adult stage, simple with less trichomes. Caudal trichomes with 2–4 hooks, but commonly 3 hooks.

Sex organs undeveloped.

Remarks: In this stadium, body with 4 segments associated, 3 pleurals, 4 pairs of legs. The 6th antennal article with 9 bacilliform sensilla forming a slightly curved row. Five fully developed ocelli. The 4th leg lacked sensillum on coxa, post-femur, tibia and tarsus 1. Caudal bundle was simple in structure as in sub-adult stage.

Stadium I, 3 pairs of legs. Measurements: Body length was 0. 3–0.5 mm (n = 5), caudal bundle measured 0.2 mm.

Colouration: Pure white when just hatched then becoming yellowish in colour, pale red in eye area.

All characteristics on the head and body were the same as stadium II. There was little difference between these stages, with the exception of a few characteristic changes. For example, the colour of the newly hatched stage changed from pure white to yellowish after a few days. Body with 3 segments associated with 3 pleural projections and a very simple caudal bundle. Caudal trichomes with 2 to 3 hooks.

Remarks. In this stadium, body with 4 segments, associated 3 pleurals, 4 pairs of legs. The 6th antennal article with 9 bacilliform sensilla forming a slightly curved row. Five fully developed ocelli. The 4th leg lacked sensillum on coxa, post-femur, tibia and tarsus 1. Caudal bundle was simple in structure as in sub-adult stage.

Colonies of Monographis quenslandicus sp. n. established for this study. Thirty colonies were established for this study with a 50% survival rate. Half the colony members died at 3 to 5 pairs of legs stage (50% mortality rate). Those that completed their life cycle passed through 7 moults before the adult stage. Moulting occurred between 10 (minimum) to 20 days (maximum), but 12 days was the most common time period and some individuals remained in stadium VIII for 20 days. The number of surviving males and females were the same in all colonies. In adult stage (stadium VIII), millipedes had one more moult before sexual maturity. Males completed their life cycle and gradually died off at this stage, but females lived and moulted once or twice before death. All colonies had individuals at different stages of development with egg laying occurring throughout the study.

DNA Sequencing Genomic DNA sequences, each with 1317 base pairs, were obtained from 4 adult specimens of Monographis queenslandicus sp. n. were deposited in Genbank with accession numbers: KF 147166 , KF 147167 , KF 147168 , KF 147169 .

Figures

FIGURE 3. Live specimen of Monographis queenslandicus sp. n. showing the body colouration A. Dorsal view, B. Ventral view, C. Colour of caudal bundle.

FIGURE 7. Eye patterns observed in developmental stages of Monographis queenslandicus sp. n ..

FIGURE 4. A. Head capsule of Monographis queenslandicus sp. n. showing eye pattern, 3 trichobotheria and 2 posterior posterior vertex trichomes. B. Collum and lateral protuberances showing pattern of trichome sockets with all trichomes removed. C. Tergite 2 with trichome socket arrangement depicted. D. Tergite 10 (last tergite) with densely packed smaller trichome sockets. (A, B, C and D drawn to the same scale). E. Structure of clypeo – labrum with 2 lateral lamellae and median cleft visible. F. Lateral palp of gnathochelarium with 11 conical sensilla (5 conical sensilla were missing) and 22 sensilla on the medial palp. G. Last sternite of holotype with ridged biarticulate funicular cylindrical sensilla indicated. H. Leg segments and chaetotaxy of the second leg and penis. Three types of seta present: 1) ridged biarticulate funicular cylindrical sensilla (L) were found in coxa, pre-femur and femur; 2) a similar small form (M) located in the posterior position on the femur, 3) setiform seta in post-femur and tibia (K). Tarsus 1 and 2 were with spine (I & J). N. enlarged image of Tarsus 1 and spines. O. Telotarsus structure with processes indicated: a: anterior process, c: claw, l: lamella, lp: lateral process, p: posterior process, s: setiform process.

FIGURE 6. A. Dorsal ornamental trichomes: trichome a: a 1 to a 14; trichome b, trichome c and the circular indentation d. B, C and F: Caudal bundle of male of Monographis queenslandicus sp. n., (B. Lateral view, C. Dorsal view, F. Caudal bundle without caudal trichomes showed structures.) D, E and G: Caudal bundle of female (D. Lateral view, E. Dorsal view, G. Caudal bundle without caudal trichomes showed different structure from male); Bt: Barbate trichomes, Oth: Ornamental trichome sockets, Cbt: Caudal bundle trichomes, Cbth: Caudal bundle trichome sockets, Nt: Nest trichomes and Nth: Nest trichome sockets. H. Tergal trichome, I. Pleural trichome, J. Nest trichome, K. Caudal trichome, L. trichome b, M. trichome c, N. Barbate trichome.