A Record of Utivarachna phyllicola (Araneae, Trachelidae) from Lampi Island, Southern Myanmar
Author
Naven Kumar, R K
Author
Sivalingam, Azhagu Madhavan
Author
Alex, Arockia
Author
Brahma, Neha
text
Bulletin of the National Museum of Nature and Science. Series A, Zoology
2022
2022-05-20
48
2
29
34
http://dx.doi.org/10.4103/jpbs.jpbs_562_23
journal article
303513
10.50826/bnmnszool.48.2_29
393dba31-cf98-4b3a-ba15-836e1018bdb1
2434-091X
13824151
Utivarachna phyllicola
Deeleman-Reinhold, 2001
Utivarachna phyllicola
Deeleman-Reinhold, 2001
, pp. 386–388, figs. 604–609.
Holotype
: male, and
one female
and
one male
paratypes
from humid evergreen forest near the entrance of tourist center, about
1,000 m
alt., in the
Khao Yai National Park
,
Nakhon Ratchasima Province
,
Thailand
,
3–7–III–1986
, P.
R
. and
C. L. Deeleman
leg., preserved in the
Naturalis Biodiversity Center
,
Leiden
(
Rijksmuseum van Natuurlijke Historie
), not examined.
Diagnosis.
ɹThis species is very unique in having an extremely developed, retrolateral tibial apophysis of the male palp (
Fig. 4
), and is easily distinguishable from other
Utivarachna
species.
However, we are not sure which species group it belongs to, because the subdivision proposed by
Deeleman-Reinhold (2001)
should be reviewed. In the key of the article (p. 372),
Utivarachna phyllicola
was treated as a species group of its own with characteristics including some variable features of the eyes and chelicerae. For instance, the posterior eye row shows different phases by the viewing angle, and the number of teeth on the retromargin of the fang furrow of the chelicera can be variable, as it is four in the present specimen, not three as specified in the key. The comparison of the palpal organs and female genitalia among species was also insufficient. Focusing on the structure of the male palp among species of the genus, in fact,
Utivarachna phyllicola
seems to be related to the species of the
U. kinabaluensis
group established by the same author, namely,
U. kinabaluensis
Deeleman-Reinhold, 2001
, from Sabah, Borneo and
U. bucculenta
Deeleman-Reinhold, 2001
, from Khao Yai National Park,
Thailand
.
Fig. 1.
Utivarachna phyllicola
Deeleman-Reinhold, 2001
, a male from Lampi Island, Myanmar. Body length: 3.6 mm.
Description.
ɹBased on a single male specimen from southern
Myanmar
. Measurements. Body length
3.60 mm
; prosoma length
1.65 mm
, width
1.33 mm
; opisthosoma length
1.95 mm
, width
1.20 mm
; lengths of legs [total length (femur+patella+tibia+metatarsus+tarsus)]: I
5.04 mm
(1.58+0.60+1.23+1.03+0.60), II
4.88 mm
(1.47+0.58+1.20+1.03+0.60), III
3.45 mm
(1.13+0.38+0.77+0.82+0.35), IV
4.53 mm
(1.30+0.45+1.00+1.28+0.50). Leg formula: I–II–IV–III.
Prosoma. Carapace wholly granulated, longer than wide (length/width 1.25), posteriorly narrowed to the width of the pedicel, with a small but distinct fovea (
Fig. 1
). Anterior eye row procurved, posterior eye row slightly procurved or straight in dorsal view, differs depending on the viewing angle. AME round, other eyes oval. ALE>PME>PLE>AME (10: 8: 7: 6), AME– AME<AME–ALE (3: 4), PME–PME>PME– PLE (8: 7), ALE and PLE close to each other. Median ocular area as long as wide, wider behind than in front (6: 4). Clypeus narrow, as same as the diameter of AME. Chelicera with three teeth on the promargin of fang furrow, four teeth on the retromargin (
Fig. 2
). Maxillae wide and round distally, labium longer than wide (length/width 1.20), sternum slightly longer than wide (length/width 1.06). Legs without spines and strong hairs, coxae of legs I and II remarkably long, as long as tibia of the legs, metatarsi of legs I and II ventrally with rows of thin hairs with granular base, metatarsi of legs III and IV apically with scopula, tarsus with claw tuft and two claws which are small and not pectinate.
Figs. 2–7.
Utivarachna phyllicola
Deeleman-Reinhold, 2001
, a male from Lampi Island, Myanmar. 2. Left chelicera, ventral view. 3. Palpal organ of the left palp, ventral view. 4. Tibia and cymbium of the left palp, dorsal view. The arrow indicates the location of the embolus visible through the cuticle of the cymbium. 5. Retrolateral tibial apophysis of left male palp, lateral view. 6. Pedicel with membranous base, ventral view. 7. Spinnerets, ventral view. Scales: 0.2 mm.
Fig. 8. Records of
Utivarachna phyllicola
Deeleman-Reinhold, 2001
, in southeast Asia.
˔
: 1. Khao Yai National Park in the Nakhon Ratchasima Province, Thailand (the type locality). 2. Mt. Kinabalu, Sabah, Borneo, Malaysia. 3. Ketambe, Gunung Leuser National Park, northern Sumatra, Indonesia. 4. Mt. Singgalang, Jambi Province, western Sumatra, Indonesia. All recorded by
Deeleman-Reinhold (2001)
. +: 5. Lampi Island, west of Malay Peninsula, Bokepying Township, Tanintharyi Region, Myanmar (the present record). The previous record in Myanmar was made by
Dankittipakul
et al.
(2011)
from Thahtay Kyun Island near Kawthaung, in the same area and about 90 km South of Lampi Island.
Male palp (
Figs. 3–5
). The basal part of femur slightly bent downward, without swelling or apophysis, the length of patella one-third of the femur, tibia basally short, the retrolateral tibial apophysis large, its apical part furnished with a sclerotized hook and the surrounding membrane (
Figs. 4–5
). Cymbium longer than wide, apically with two strong hairs, palpal organ large and globular, without distinct tegular apophysis and conductor, embolus filiform, long, coiled around the tegulum and visible through the cymbium as shown by the arrow on
Fig. 4
, the tip of embolus reaches the end of the cymbium.
Opisthosoma. Bullet-shaped, longer than wide (length/width 1.63), covered with an indistinct, thin dorsal plate (
Fig. 1
). Pedicel relatively short, cylindrical, basally covered by membranous structure (
Fig. 6
). Colulus absent, replaced by a pair of vestigial hairs, all spinnerets without distinct large spigots, anterior-lateral spinnerets semi-cylindrical, thicker than others, median ones small and short, posterior-lateral ones longest (
Fig. 7
).
Coloration and markings (
Fig. 1
). Prosoma: Carapace brown with three pairs of black dots on both sides; chelicerae, maxillae, labium and sternum brown; coxa, trochanter, the basal two thirds of femur of leg I and the middle part of femur of leg II also brown, other segments of leg I and II yellow; legs III and IV basally light yellowish brown, distally yellow. Opisthosoma: dorsal plate light yellowish brown with indistinct markings; other parts yellowish white; spinnerets yellow.
Distribution (
Fig. 8
).
Myanmar
(
Tanintharyi Region
);
Thailand
,
Indonesia
(
Sumatra
),
Malaysia
(Borneo).