Taxonomy of the Proisotoma complex. II. A revision of the genus Subisotoma and a description of Isotopenola gen. nov. (Collembola: Isotomidae)
Author
Potapov, Mikhail
Author
Babenko, Anatoly
Author
Fjellberg, Arne
Author
Greenslade, Penelope
text
Zootaxa
2009
2314
1
40
journal article
10.5281/zenodo.191990
c4ef1d49-71d3-4dd5-ab25-e2c0a9b23e38
1175-5326
191990
Isotopenola loftyensis
(
Womersley, 1934
)
Figs 11
,
97–105
Cryptopygus loftyensis
Womersley, 1934
: 88
Proisotoma (Subisotoma) loftyensis
(
Womersley, 1934
)
:
Greenslade 1994
Material.
Lectotype
(designation by
Greenslade (1994))
, Mt Osmond, South
Australia
. 4 individuals, South
Australia
, Mt Lofty Ranges, Belair Nat.Park, near second waterfall on creek,
14.vii.1973
, under bark of
Eucalyptus
, leg. P. Greenslade (
SAMA
); 2 individuals, South
Australia
, Mt Lofty Ranges, Glen Osmond, leg. P. Greenslade (546) (
SAMA
)
Redescription.
Size 1.1–1.6 mm. Colour unknown in our specimens (entirely blue from first description). Body plump, with cryptopygy. Cuticle with pits regularly scattered all over body, larger on head (
Fig. 97
). A part of corpus and head with secondary granulation. All 8+8 ocelli, G and H smaller and hardly visible. PAO wide elliptic, without constriction, 1.6–1.8 as long as ocellus diameter and 0.8–1.0 as long as U3. Maxillary palp simple, 4 sublobal chaetae present. Labrum with 2/554 chaetae. Labium with all papillae A–E present, papilla E with 4 guard chaetae, proximal chaetae 3. Basomedial field of labium with 4 chaetae. Ventral side of head with 4–6+4–6 postlabial chaetae along ventral line. Ant.1 with about 19 common chaetae, 2 bms (dorsal and ventral) and 2 ventral sensilla (s) (
Figs 98, 99
), Ant.2 with 3 bms and 1 distal s, Ant.3 without bms and with 5 distal s, including one lateral in
АО
. Inner sensilla of
АО
clearly broadened, as long as outer ones, additional sensilla absent. Ant.4 with numerous poorly differentiated sensilla, subapical organite small, microsensillum present.
All terga with dense cover of uniform chaetae (
Fig. 97
). Macrochaetae not differentiated. Dorsal axial chaetom of Th.II–Abd.III as 10–11,8–10/7–9,7–8,7–8. Tergal sensilla distinctly differ from ordinary chaetae, short and slender, uniformly distributed on the terga. With numerous sensilla on terga. The total number of sensilla not stable (13,10/7,8,10,15,16 in one specimen studied by us in detail,
Figs 11
,
97
). The number of tergal microsensilla 11/111. Sterna of Th.III without chaetae.
Unguis with clear inner tooth. Ti.1–3 with many additional proximal chaetae, the total number 27–30 on Ti.1 and more than 30 (up to 40) on each Ti.2 and 3 (
Figs 100–102
). Tibiotarsal tenent chaetae 1–2–2, clavate, longer than inner edge of unguis (U3: t.ch. = 0.7). Ventral tube with 4+4 lateral and about 8 posterior chaetae (only one specimen checked). Tenaculum with 4+4 teeth and one chaeta. Submedial setaceous fields on Abd.III sterna with 5–10 chaetae, anterior furcal subcoxae with 12–16 chaetae, posterior ones with 11–13. Manubrium without anterior chaetae, posterior face with about 27 chaetae centrally and 4+4 laterobasal lobes (only one specimen checked). Dens with one anterior and 5–6 posterior chaetae. Mucro long, with 2 teeth, more or less clearly set off from dens (
Figs 103–105
). Ratio of manubrium: dens: mucro = 4.5–5.1: 3.1–4.1: 1.
Affinity.
This second Australian species of
Cryptopygus
described by Womersley undoubtedly belongs to
Isotopenola
. The presence of numerous sensilla on body, no needle-like but normal chaetae, more chaetae on postlabial area, tibiotarsi, antennae and other features distinguish
I. loftyensis
from
I. australis
. More abundant clothing of chaetae in
loftyensis
than in
australis
was also mentioned by Womersley in first description. Our redefinition of this species is based on
lectotype
from South
Australia
(Mount Osmond) and several specimens collected by P.Greenslade close by. The most important characters, as chaetotaxy of Ant.I and dens, approximate number of sensilla on body, were possible to see in
lectotype
.
We have also several undescribed forms/species from several localities in Australian Capital Territory, Victoria, South
Australia
(all leg. P. Greenslade) and
New Hebrides
(leg L. Deharveng & A. Bedos) sharing many characters with
I. loftyensis
which differ in number of tergal sensilla, chaetae on appendages, sensilla on Ant. I, e-guard chaetae on labium and other features. Taxonomical relations of these forms calls for further special study.
Distribution.
Currently known only from South
Australia
.