Acanthocyrtus, Handschin, 1925

Cipola, Nikolas Gioia & Greenslade, Penelope, 2022, Two new species of Acanthocyrtus Handschin, 1925 (Collembola, Entomobryidae Entomobryinae) from Western Australia, Zootaxa 5124 (3), pp. 341-358 : 356

Key to species of Acanthocyrtus

1 Tenent hair chavate ( Fig. 8E ); Australian species............................................................ 2

- Tenent hair pointed; African species................................................ A. marginalis Salmon, 1956

2 Prelabral chaetae ciliate................................................................................ 3

- Prelabral chaetae smooth............................................................................... 4

3 Head with 7 sutural mac; Th II–III respectively with 9 and 7 mac in p1–3 complex; Abd I with 4 mac; Abd IV with 19 central mac.......................................................................... A. lineatus Womersley, 1934

- Head with 5 sutural mac; Th II–III respectively with 4 and 5 mac in p1–3 complex; Abd I with 2 mac; Abd IV with 15 central mac............................................................................ A. spinosus ( Schött, 1917)

4 Labral papillae present ( Figs 3E , 9C )..................................................................... 5

- Labral papillae absent.................................................................................. 6

5 Head and Abd III–IV with lateral spots ( Fig. 2 ); labral inner papillae conical, outer papillae reduced to a small rounded projection ( Fig. 3E ); labial papilla E l.p. surpass the base of a.a. ( Fig. 4A ); manubrium ventro-distally with 3 inner chaetae ( Fig. 7B ) A. necropolitanus sp. nov.

- Head and trunk depigmented ( Fig. 8 ); labral inner papillae with 3 projections and outer papillae with 4 projections ( Fig. 9C ); labial papilla E l.p. not reach the base of a.a. ( Fig. 9E ); manubrium ventro-distal with 2 inner chaetae ( Fig. 11F )................................................................................................ A. pallidus sp. nov.

6 Ant IV apical bulb bilobed; Th II with 24 mac in p1–3 complex; Abd III with 5 lateral mac; Abd IV with 20 central mac; mucronal proximal tooth clearly smaller than distal, mucronal basal spine surpassing the proximal tooth........................................................................... A. barrowensis Zhang, 2009 (in: Zhang et al. 2009)

- Ant IV apical bulb absent; Th II with 17 or less mac in p1–3 complex; Abd III with 4 lateral mac; Abd IV with 15 or less central mac; mucronal teeth subequal, mucronal spine reaching the apex of proximal tooth................................. 7

7 Head S1 and S4 mac present and Pe5 absent; labial basomedian field with 3 smaller chaetae (M2, R and RS); Th II with 6 and 17 mac respectively in m2 and p3 complex; unguis a.t. absent............ A. loftyensis Zhang, 2009 (in: Zhang et al. 2009)

- Head S1 and S4 mac absent and Pe5 present; labial basomedian field with 1 smaller chaetae (M2, RS absent); Th II with 5 and 15 mac respectively in m2 and p3 complex; unguis a.t. present............. A. yolngui Zhang, 2009 (in: Zhang et al. 2009)

Figures

FIGURE 2A–B. Acanthocyrtus necropolitanus sp. nov., habitus of specimens fixed in ethanol (lateral view): A, specimen with weak pigments on trunk lateral; B, pigments absent on trunk lateral. Scale bars: 0.5mm.

FIGURE 3A–F. Acanthocyrtus necropolitanus sp. nov., antennae and dorsal head; A, apex of left Ant IV (dorsal view); B, Ant III distally (lateral view); C, chaetotaxy (mac and elongated sens) of left Ant III–I (dorsal view, from left to right), respectively; D, chaetotaxy of clypeus and prelabrum; E, labral papillae (ventral view); F, head dorsal chaetotaxy and eyes (dorsal view, left side).

FIGURE 4A–D. Acanthocyrtus necropolitanus sp. nov., ventral head (right side); A, labial papillae E (right side); B, maxillary palp and sublobal plate (right side); C, basomedian and basolateral labial fields and proximal chaetae; D, complete postlabial chaetotaxy.

FIGURE 7A–E. Acanthocyrtus necropolitanus sp. nov., abdominal appendages; A, collophore (lateral view); B, distal manubrium (ventral view); C, manubrial plate (dorsal view), arrow indicates chaeta present or absent; D, dens spines chaetotaxy (dorsal view), E, distal dens and mucro (dorsal view).

FIGURE 8. Acanthocyrtus pallidus sp. nov., habitus of specimens fixed in ethanol (lateral view). Scale bars: 0.5mm.

FIGURE 9A–F. Acanthocyrtus pallidus sp. nov., antennae and head; A, chaetotaxy (mac and elongated sens) of left Ant III–I (dorsal view, from left to right), respectively; B, chaetotaxy of clypeus (dorsal view); C, labral papillae (ventral view); D, head dorsal chaetotaxy and eyes (dorsal view, left side); E, labial papillae E (ventral view, right side); F, complete postlabial chaetotaxy (ventral view, right side).

FIGURE 11A–H. Acanthocyrtus pallidus sp. nov., legs and abdominal appendages; A–C, chaetotaxy of left subcoxa I–III respectively (outer side); D, trochanteral organ (posterior view); E, collophore (lateral view), arrow on lateral flap indicate smooth chaeta present or absent; F, distal manubrium (ventral view); G, manubrial plate (dorsal view); H, dens spines chaetotaxy (dorsal view),