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A New Species of the Ant Genus Lasiomyrma (Hymenoptera,
Formicidae, Myrmicinae) from ailand
by
Weeyawat Jaitrong
ABSTRACT
A new species of the genus Lasiomyrma is described from ailand under
the name, L. wiwatwitayai Jaitrong, sp. nov., based on the worker caste. is
species probably constructs its nests in rotten wood on the forest oor.
Keywords: Ant, Lasiomyrma wiwatwitayai, new species, taxonomy, ai-
land.
INTRODUCTION
e genus Lasiomyrma Terayama et Yamane is one of the rare ant gen-
era, and belongs to the subfamily Myrmicinae. e members of the genus
are mainly distributed in the tropical rain forest of Sundaland (Terayama
and Yamane, 2000). Currently, only three species are known: Lasiomyrma
gedensis Terayama et Yamane from Java, Indonesia; Lasiomyrma gracilinoda
Terayama et Yamane and Lasiomyrma maryatiae Terayama et Yamane from
Sabah (Bormeo), Malaysia (Terayama and Yamane 2000; Bolton 2003; Bolton
et al. 2006).
Recently I have examined a few specimens of this genus collected from
ailand and deposited in the collection of the Natural History Museum of
the National Science Museum (ailand) and the Ant Museum of Kasetsart
University (ailand). ese specimens are of the same species that should
be new to science. In the present paper I describe this as a new species based
on the worker caste. is represents a rst record of Lasiomyrma from the
continental Asia.
e measurements, indices and morphological terms used in this paper
follow those of Terayama and Yamane (2000).
ailand Natural History Museum, National Science Museum, Technopolis, Khlong 5, Khlong Luang,
Pathum ani, 12120 ailand
Email: polyrhachis@yahoo.com
427
428 Sociobiology Vol. 55, No. 2, 2010
DESCRIPTION
Lasiomyrma wiwatwitayai Jaitrong, sp. nov.
Figs. 1-3
Types . Holotype: worker from hill evergreen forest, Khao Yai, NE. ai-
land, 30 V 2000, D. Wiwatwitaya leg. Paratypes: a worker from secondary
forest, Khao Yai, Nakon Ratchasima Prov., NE. ailand, 29 V 2000, W.
Jaitrong leg.; a worker from Bueng Si To, 900-1,400 m asl., Khao Soi Dao,
Chanthaburi Prov., Soi Dao Dist., 22 I 2008, W. Jaitrong leg.
Type depository. e holotype is deposited in the Ant Museum of Kasetsart
University (ailand), and two paratypes are in Natural History Museum of
the National Science Museum (ailand).
Measurements. Wo r k e r (n = 3): TL (total length) 2.6-2.9 mm; HL (head
length) 0.70-0.73 mm; HW (head width) 0.63-0.65 mm; SL (scape length)
0.43-0.45 mm; WL (Weber’s length of alitrunk) 0.90-0.93 mm; PW (pro-
notal width) 0.50-0.53 mm; PL (petiole length) 0.33-0.35 mm; PH (petiole
height) 0.28 mm; DPW (petiole width in dorsal view) 0.18-0.20 mm; PPL
Fig. 1. Lasiomyrma wiwatwitayai sp. nov., holotype, head in full-face view.
429
Jaitrong, W. — A New Species of the Ant Genus Lasiomyrma From ailand
(postpetiole length) 0.18-0.20 mm; PPH (postpetiole height) 0.23 mm;
PPW (postpetiole width) 0.25 mm; CI (cephalic index = HW/HL x 100)
86-90; SI (scape index = SL/HW x 100) 65-68.
Worker Description (holotype and paratypes). Head in full-face view
slightly longer than broad (1.11-1.12 times as long as broad), with slightly
convex sides and very weakly concave posterior margin. Eye 0.18 mm in
maximum diameter, with 9 omatidia along the longest axis. Antenna 11-seg-
mented; scape extending beyond half of head length, but not reaching the
posterolateral corner of head in full-face view; antennal segment II longer and
broader than each of III-VIII; III-VIII each broader than long; the terminal
segment (XI) large, almost 1.7 times as long as IX and X combined; antennal
club indistinct with 2 or 3 segments. Clypeus convex anteriorly and lacking
teeth. Mandible elongate-triangular with apical tooth large, followed by 7
denticles; basal margin of mandible lacking denticles.
Alitrunk rather robust; pronotum and mesonotum fused to form a
dome, with a very shallow suture between them in at least two specimens,
seen from above much broader anteriorly than posteiorly, laterally slightly
convex; anterior margin of pronotum produced medially; mesonotum with
a steep and short posterior slope. Mesopleuron rather short; anepisternum
Fig. 2. Lasiomyrma wiwatwitayai sp. nov., holotype, habitus in prole.
430 Sociobiology Vol. 55, No. 2, 2010
clearly demarcated from katepisternum by a deep groove. Metanotal groove
relatively shallow and indistinct. Propodeum in prole extremely lower than
promesonotum, with its dorsal outline slightly straight and distinctly slop-
ing to the base of propodeal spine, seen from above dorsum and declivity of
propodeum concave; propodeal spine obtusely angulated, shorter than broad
at base. Propodeal lobe producted posteriorly.
Petiole pedunculate, slightly longer than high, with a thin node; the node
reversed U-shaped in prole; subpetiolar process weakly developed, with its
ventral outline almost straight. Postpetiole short, slightly shorter than high
and broad, with convex dorsal margin in prole.
Gaster large and oval, in dorsal view 0.70-0.73 mm in maximum width,
slightly broader than head.
Whole head covered with dense punctures (almost reticulate); area between
frontal carinae with several longitudinal rugulae. Mandible almost smooth
and shiny except at the base where short longitudinal rugulae are present.
Antennal scape punctate but spaces between punctures smooth and shiny.
Fig. 3. Lasiomyrma wiwatwitayai sp. nov., holotype, body in dorsal view.
431
Jaitrong, W. — A New Species of the Ant Genus Lasiomyrma From ailand
Promesonotum with dense punctures (a condition similar to the head);
mesopleuron with dense punctures; metapleuron and sides of proprodeum
with dense rugulae, but sparsely punctate; dorsum and declivity of propodeum
with more than 10 transverse rugulae. Anterior face of petiolar node smooth
and shiny, but posterior face with dense punctures; whole postpetiole with
smaller and dense punctures. First gasteral segment (tergite and sternite)
punctate, others smooth and shiny.
Body reddish brown to dark brown; antenna and mandible yellowish
brown to dark brown; legs reddish brown to dark brown.
Etymology. e species epithet is dedicated to Dr. Decha Wiwatwitaya
of the Ant Museum, Kasetsart University, who loaned me the holotype.
Distribution. ailand.
Remarks. is is a rst record of this genus from the continental Asia. e
holotype and a paratype were taken from rotten wood on the forest oor in
a highland (800-1,400 m alt.) hill evergreen forest, but the other paratype
was collected in a lowland secondary forest. us L. wiwatwitayai inhabits
forests located from lowland to highland, probably nesting in rotten wood.
is species is distinguished from the other congeners by the promesono-
tum that is broader and dorsally more strongly convex than in the latter, the
propodeal dorsum that is straight in prole and distinctly slopes to the base
of the propodeal spines, and by the propodeal spine that is obtusely angu-
lated and shorter than broad at base (in the latter it is longer than or as long
as broad at base).
ACKNOWLEDGMENTS
I would like to express my deep gratitude to Dr. Decha Wiwatwitaya of
the Ant Museum, Kasetsart University for allowing me to check the ant
specimens at the museum, and Professor Seiki Yamane for critical reading of
earlier dras of the manuscript.
REFERENCES
Bolton, B. 2003. Synopsis and classication of Formicidae. Memoirs of the American
Entomological Institute 71: 370 pp.
Bolton, B., G. Alpert, P.S. Ward & P. Naskrecki 2006. Bolton’s Catalogue of Ants of the
World, 1758-2005 [CD-ROM]. Harvard University, Cambridge.
Terayama, M. & Sk. Yamane 2000. Lasiomyrma, a new Stenammine ant genus from Southeast
Asia (Hymenoptera: Formicidae). Entomological Science 3 (3): 523-527.