Description of new apterous winter species of Leuctra (Plecoptera: Leuctridae) based morphology and DNA barcoding and further records to stonefly fauna of the Caucasus, Georgia
Author
Teslenko, Valentina A.
Author
Palatov, Dmitry M.
Author
Semenchenko, Alexander A.
text
Zootaxa
2019
2019-04-15
4585
3
546
560
journal article
27294
10.11646/zootaxa.4585.3.9
9b404efd-c9b4-4d83-bc6d-1fa39672a9c6
1175-5326
2640279
E6BBA677-EB76-461E-ACBC-FE57E1E5926E
Leuctra georgiae
Teslenko
sp. n.
(
Figs. 14–24
)
urn:lsid:zoobank.org:act:
C6A3B5AB-A3CC-40B0-B8F0-C4ED8C313243
Material examined.
Holotype
male.
Georgia
.
Adjaria
.
Kintrishi River
,
16 km
upstream from Kobuleti
and
4 km
upstream from Tchakhati Village
,
41°47.192 N
41°57.390 E
, 0 6.02.2017, coll.
D. Palatov
(
FSC
EATB FEB
RAS)
.
Paratypes
:
3 males
(
1 male
mounted),
5 females
(
2 females
mounted), same locality and date, coll.
D. Palatov
(
FSC
EATB FEB
RAS)
.
Description.
Dark brown, apterous species, with tiny rudimentary wings, appearing as dark brown plates on the meso- and mesothorax; body length of males 4.0–
4.2 mm
, females 5.2¯
6.2 mm
. Setation distinct, sclerotization heavy (
Figs. 14, 15
). Palpi, head, pronotum, meso- and metanotum, legs uniform black brown without pattern (
Fig. 14
). Head bears two very small lateral ocelli, poorly visible, the median ocellus indistinct, difficult to distinguish (
Fig. 14
).
The sclerite configuration on the female prothoracic and mesotoracic sterna of
L. georgiae
is similar to that of
L. adjariae
(
Figs. 3
,
20
), except for prothoracic furcasternum as a pair of diverging bars which is larger and touching basisternum; prothoracic spinasternum of
L. georgiae
is oval, and mesothoracic basisternum having a concave anterior margin (
Fig. 20
).
Male.
Terga I-VII simple, heavily sclerotized, except semicircular paramedian poorly pigmented areas on posterior margins, which are increased in size to tergum VII and covered by long black setae. Tergum VIII bears anteromedial sclerotized process armed with a pair of triangular, heavily sclerotized teeth directed backward and covered by long black setae (
Fig. 16
). In lateral view teeth raised oblique upward and forward (
Fig. 15
). Tergum IX mostly unpigmented with distinct antecosta, divided medially on more than one fifth of segment width; posteromedial sclerite consists of pair pigmented triangular spots, disconnected at base (
Figs. 16
,
17
). Tergum X deeply cleft, bilobed, each lobe with oblique mesal edge in dorsal view, bears a small posteromedial process, covered with tuft long black setae (
Figs 16
,
17
). Between the lobes a small rounded membranous epiproct appears; a large conspicuous V-shaped pigmented sclerite is behind the epiproct (
Figs. 18, 19
). Cerci long, slim (
Figs. 16- 18
), more sclerotized along inner edges than along outer ones, covered with long setae, especially along outer edges; apices round, not pigmented with vestigial terminal segment modified into an ‘eye-spot’ mark. In dorsal view cerci form a circle around styles (
Figs. 17, 18
). Paraprocts strong, styles more 2.0X shorter than specilla (
Figs. 16
,
17
). Styles base wide with triangular truncate lateral edges (
Figs 16
,
19
), and ending in strong sclerotized tapered to the tips, gently bent inward (
Figs 16
,
17
) processes. Specilla gently tapered to the tip, apices blunt, gently bent outside in dorsal view (
Fig. 18
). Sternum IX with U-shaped unsclerotized area, ventral vesicle absent, a tiny, indistinct knob on the anteromedial margin weakly visible (
Figs. 14, 15
).
FIGURES 14–16.
Male of
Leuctra georgiae
sp. n.
14. Habitus, dorsal view. 15. Abdominal tip, lateral. 16. Abdominal tip, dorsal.
FIGURES 17–19.
Male of
Leuctra georgiae
sp. n.
17. Abdominal tip, IX & X terga, dorsal. 18. Abdominal tip, IX & X terga, ventral. 19. Epiproct, dorsal.
Female
. Sterna with wide ventral sclerite and pair lateral membranous bands (
Fig. 21
). Sternum VIII forms a rectangular subgenital plate with two rounded posteromedial lobes (
Figs 21, 22
). In ventral view of a cleared specimen (
Fig. 22
) in ¾ of the length of the subgenital plate one notices a pair of lateral wing-shaped processes covered with black setae; each process tapered to the tip and directed to outside, makes subgenital plate slightly wider, than at anterior or posterior margin (
Fig 22
); the last third of subgenital plate bilobed, posteromedian lobes rounded with slightly concaved posteromedian margin (
Figs 21, 22
). A median less-pigmented area divides the posteriomedian lobes (
Fig. 22
). Subgenital plate fused with paragenital plate being dark brown that can be seen by transparency (
Fig. 22
). Paragenital plate with paired fan-shaped processes, directed sideward and slightly overhang from under of posterolateral corners of the subgenital plate (
Fig. 22
). Sternum IX completely sclerotized, with a produced arch-shaped extension anteromesally and pair of small triangular anretolateral unpigmented spots below subgenital plate (
Figs 21, 22
). Seminal receptacle spheroid (
Figs 23, 24
), spermathecal sclerite ring-shaped, with strongly sclerotized semi-ring which ends in a pair of small teeth; the teeth joined to each other by slightly sclerotized a central arch (
Figs 22, 24
).
FIGURES 20–24.
Female of
Leuctra georgiae
sp. n.
20. Pro- meso- and methatorax. 21. Abdominal tip, subgenital plate, ventral. 22. Subgenital plate and spermatheca, cleared, mounted, ventral. Right edge of paragenital plate and right lateral wingshaped process noted by arrows correspondingly. 23. Spermatheca, cleared, mounted ventral. 24. Spermatheca, cleared, mounted, ventrolateral.
FIGURES 25–28.
25. Collecting place of
Plecoptera in Adjaria
, Georgia (black dot). Square shows the nearest collecting site of
Capnioneura gouanerae
in Artvin, Turkey. 26. Female
of
Leuctra adjariae
sp. n.
on the snow. 27 & 28. The Kintrishi River, Meskheti Range, the type locality of
Leuctra adjariae
sp. n.
and
Leuctra georgiae
sp. n.
Photo by D. Palatov.
Diagnosis.
Apterous in both sexes.
Leuctra georgiae
is distinguished from other
Leuctra
species by the pair of short, triangular and heavily sclerotized anteromedial processes on male tergum VIII in combination with pair of pigmented triangular posteromedial spots on tergum IX. The male is also distinguished by tergum X deeply notched with small paired posteromedial processes, covered with long setae; epiproct small, rounded and membranous; styles shorter specilla more than
2X.
The female is characterized by a rectangular subgenital plate with two lateral wing-shaped processes, posterior margin of subgenital plate with paired posteromedian rounded lobes.
Affinities.
Based on tergal ornamentation of the male,
L. georgiae
possibly belongs to the
prima
species subgroup within the
hippopus
species group according to Ravizza & Vin ҫon (1998) and
Ravizza (2002)
. Within the
prima
subgroup, the male of
L. ligurica
Aubert, 1962
has similar paired anteromedial sclerotized processes on tergum VIII. In
L. ligurica
they are pointed at the apices, whereas in
L. georgiae
, the apex of each anteromedial process is rectangular. The posteriomedial sclerite on tergum IX is rectangular in
L. ligurica
, the same sclerite of
L. georgiae
appears as a pair of pigmented triangular spots, which are disconnected at the base. The females of both species are only generally similar in rectangular shape of subgenital plates with a bilobed posterior margin. However, the female genitalia differ in detail. The spermatheca of
L. georgiae
has a strongly sclerotized central arch and caudally connected arms, similar to
L. ligurica
and some members of the
prima
sub-group. Both species are apterous and are distributed within a relatively small area in the different mountain systems.
Leuctra ligurica
is known from the western edge of the Ligurian Apennines to the eastern margin of the Ligurian Alps (
Ravizza 2002
);
L. georgiae
occurs on the western slopes of Meskheti Range (Lesser Caucasus) in
Adjaria
,
Georgia
.
Furthermore, the styles of
L. georgiae
resemble remotely the styles of
L. tarnogradski
,
which are short.
L. georgiae
also differs from
L. tarnogradski
by the different shape of the posteromedial sclerite on tergum IX, by the lack of ventral vesicle on sternum IX, by the lack of wings, and by the very different shape of the female subgenital plate (
Zhiltzova, 2003
).
Distribution.
Apparently, larvae of
L. georgiae
occur in the Kintrishi River, near the town of Kobulety located in
Adjaria
in the southwestern corner of
Georgia
bordered
Turkey
to the south and the eastern end of the Black Sea (
Fig. 25
). The Kintrishi River flows down from western slopes of Meskheti Range (Lesser Caucasus) into the Black Sea. The Kintrishi River at the
type
locality on altitude
180–190 m
a.s.l. flows through a canyon with a width
5–6 m
(
Figs. 27, 28
). Despite the river being at flood stage, the water was clear, flowing at
0.3–0.9 m
/s. Adults of
L. georgiae
were collected walking on the snow.
Etymology.
This species is named after
Georgia
, where it occurs.