KEY TO SUBFAMILIES OF VIETNAMESE ANTS
BASED ON THE WORKER CASTE

Based on Eguchi et al. (2011)

© Katsuyuki EGUCHI & BUI Tuan Viet, 2007. All rights reserved.
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1 Pygidium (abdominal tergite VII) flattened or impressed, posterolaterally with a single pair of spines [IMG] or a series of peg-like spines [IMG].

2

- Pygidium convex, unarmed [IMG], but hypopygium (abdominal sternite VII) rarely armed with a series of spines posteriorly.

3

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2
(1)

Pygidium posterolaterally with a single pair of spines [IMG]; promesonotal suture distinct dorsally [IMG].

Dorylinae (Dorylus)

- Pygidium posterolaterally with a series of peg-like spines [IMG]; promesonotal suture absent dorsally [IMG].

Cerapachyinae

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3
(1)

A single reduced and isolated segment, i.e. petiole (= abdominal segment II), present between mesosoma and gaster [IMG] [IMG].

4

- Two reduced and isolated segments, i.e. petiole and postpetiole (= abdominal segments II and III), present between mesosoma
and gaster [IMG].

11

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4
(3)

Gastral segment II (= abdominal segment IV) arched and down-curved [IMG].

5

- Gastral segment II neither arched nor down-curved [IMG] [IMG].

6

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5
(4)

In full-face view antennal sockets mostly to entirely exposed, located a little in front of the line across mandibular bases [IMG] or on a shelf-like frontoclypeal region overhanging mandibles [IMG].

Proceratiinae (part)

- In full-face view antennal sockets mostly to entirely covered by frontal lobe, located a little behind the line across mandibular bases [IMG].

Ectatomminae (Gnamptogenys)

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6
(4)
Petiole broadly attached to gastral segment I (= abdominal segment III); gastral segment I above helcium without a free anterior face [IMG].

Amblyoponinae (part)

Petiole narrowly attached to gastral segment I; gastral segment I above helcium with a free anterior face [IMG].

7

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7
(6)

Antennal sockets located on shelf-like frontoclypeal region that overhangs the mandibles; frontal lobes fused to each other and
forming a vertical plate [IMG].

Proceratiinae (Probolomyrmex)

- Antennal sockets located behind clypeus; shelf-like frontoclypeal region absent; frontal lobes variable in size and shape, but
never forming a vertical plate [IMG].

8

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8
(7)
Petiole extremely large and long; pygidium longer than gastral segment I [IMG].

Amblyoponinae (Opamyrma)

- Petiole relatively small and short; pygidium shorter than gastral segment I [IMG].

9

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9
(8)

Sting present and functional (even if the sting fully retracted, it may be seen through sternites of the abdominal apex); gastral
tergite I (= abdominal tergite III) fused with gastral sternite I, but the suture present [IMG]

Ponerinae

- Sting absent; gastral tergite I largely or entirely separated from gastral sternite I [IMG].

10
(
Dolichoderinae or Formicinae)

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10
(9)
Apex of hypopygium forming acidopore which appears usually as a short nozzle surrounded by hairs [IMG], or at least as a semicircular to circular emargination of the apical margin of the hypopygium [IMG].

Formicidae

- Apical margin of hypopygium truncated, never forming acidopore [IMG]; hypopygium sometimes folded along its midline,
and so apical margin of hypopygium showing a U- or V-shaped appearance but never forming a semicircular to circular emargination.

Dolichoderinae

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11
(3)

Pronotum and mesonotum completely separated by promesonotal suture [IMG].

12

- Pronotum and mesonotum completely fused; promesonotal suture either entirely absent across dorsum of mesosoma [IMG]
or present as a weak transverse furrow.

13

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12
(11)

Eye well-developed [IMG].

Pseudomyrmecinae (Tetraponera)

- Eye absent [IMG] or, in intercastes of some Protanilla species, eye often present but consisting of only one or a few ommatidia.

Leptanillinae

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13
(11)
Postpetiole (= abdominal segment III) relatively massive, not much reduced in comparison with gastral segment I (= abdominal
segment IV) [IMG].

Proceratiinae (part of Proceratium)

- Postpetiole much smaller than gastral segment I [IMG].

14

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14
(13)

When mouthparts fully closed, prementum (prm) largely visible between stipites of maxillae (stp) [IMG]; antennal socket in full-face view usually (but not always) concealed, partly or entirely, by frontal lobe; antennal socket usually far from anterior
margin of head; eye usually (but not always) present [IMG].

Myrmicinae

- When mouthparts fully closed, prementum (prm) not visible, or largely concealed behind labrum (lbr) and stipites of maxillae (stp) that meet along the midline [IMG]; antennal socket in full-face view fully exposed; clypeus narrow from front to back especially in front of antennal insertion, bringing the antennal sockets very close to the anterior margin of the head; eye
always absent [IMG].

Aenictinae (Aenictus)

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