New Asian ants of the tribe Basicerotini, with an on-line computer interactive key to the twenty-six known Indo-Australian species (Hymenoptera: Formicidae: Myrmicinae).

Invertebr. Taxon., 1990, 4, 397-425

79

New Asian Ants of the Tribe Basicerotini, with an On-line
Computer Interactive Key to the Twenty-six Known
Indo-Australian Species (Hymenoptera : Formicidae : Myrmicinae)

Robert W. Taylor

Australian National Insect Collection, CSIRO Division of Entomology, G.P.O. Box 1700,
Canberra 2601, Australia.

Abstract

The 24 known Old World species of Eurhopalothrix Brown and Kempf and 2 of Rhopalothrix Mayr
are reviewed. All are Indo-Australian. Nine species are described as new: Eurhopalothrix browni
(Sabah); E. chapmani (Luzon); E. coronata (Sumatra, Sarawak, Sabah); E. dubia (Sabah); E. jennya
(Sarawak); E. omnivaga (W. Malaysia, Sumatra, Sarawak, Sabah, Sulawesi); E. platisquama (W.
Malaysia, Sumatra); E. rothschildi (Sarawak) and E. seguensis (Sarawak). These and the 3 previously
described Asian Eurhopalothrix species are illustrated and their distributions mapped. E. philippina
Brown & Kempf is recorded from Luzon. All palaeogean basicerotines are keyed conventionally, and
an on hne computer interactive key to all is offered on disc.

Introduction

The two genera discussed here are members of the myrmicine tribe Basicerotini, which
occurs disjunctly in the Indo-Australian area, and in the neotropical and southern nearctic
regions (Brown & Kempf 1960; Taylor 1980). Apart from the very different Afrotropical/
Oriental genus Myrmicaria Saunders, and the related monotypic neotropical genus Talaridris
Weber, they are the only known myrmicines with 7-segmented antennae. Eurhopalothrix
Brown & Kempf has triangular mandibles, and those of Rhopalothrix Mayr are hnear, with
remote insertions and an apical cluster of acute teeth.

Nine new south-east Asian species of Eurhopalothrix are described. They bring to 12 the
tally of species known from areas west of New Guinea. Others previously recorded from
this region are E. heliscata Wilson & Brown, 1984 [Bukit Timah, Singapore, (0r20'N.,
103°46'E.) and Sungei Menyala Forest Reserve, Negeri Sembilan, W. Malaysia] (Figs 19-22,
49), E. philippina Brown & Kempf, 1960 (Luzon and Negros Is, Philippines, see below)
(Figs 27-29, 51), and E. procera (Emery, 1897) {-Rhopalothrix borneensis Wheeler, I9I9)
(widespread, ranging from southern Taiwan and Borneo to the Philippines, Melanesia,
N.E. Australia and Samoa) (Figs 35-37, 53). All 12 Asian species are comprehensively
illustrated with scanning electron micrographs, and they are included in a key to the workers
of all known Old World basicerotines. Known distributions of the new species are mapped,
and known sympatric associations graphically summarised (Fig. I).

The known palaeogean species of Eurhopalothrix thus now total 24, including those
previously described from Melanesia, AustraUa and Polynesia. Rhopalothrix is also repre-
sented in the region by 2 species. The previously described eastern Australian basicerotines
include (in addition to E. procera): Eurhopalothrix australis Brown & Kempf, 1960 (eastern
Australia); E. biroi (Szabo, I9I0) (New Guinea); E. brevicornis (Emery, 1897) (New Guinea);
E. caledonica Brown & Kempf, I960 (New Caledonia); E. cinnamea Taylor, 1970 (New

0818-0164/90/020397$08.00

398

R. W. Taylor

Britain); E. emeryi (Forel, 1912) (Fiji); E. greensladei Taylor, 1968 (Solomon Is); E. hoplites
Taylor, 1980 (New Guinea); E. insidiatrix Taylor, 1980 (Fiji); E. isabellae (Mann, 1921)
(Solomon Is); E. punctata (Szabo, 1910) (New Guinea) and E. szentivanyi Taylor, 1968
(New Guinea); Rhopalothrix diadema Brown & Kempf , 1960 (New Guinea) and R. orbis Taylor,
1967 (eastern Australia).

12 13 14

15 16

17 18

200 400
kilometres

BROWNI

CHAPMANI

CORONATA

DUBIA

JENNYA

HELISCATA

• •

OMNIVAGA

PHIUPPINA

PLATISQUAMA

ROTHSCHILDI

SEGUENSIS

Fig. 1. Summary distribution of southeast Asian Eurhopalothrix species, apart from E. procera.
Localities represented by the numbered columns are: (1) Sungei Simei Falls; (2) near Kuala Kubu Bahru;
(3) Ulu Gombak Field Station and vicinity; (4) Sungei Menyala Forest Reserve; (5) Liwa; (6) Gunong
Pulai; (7) Bukit Timah Reserve; (8) Kampong Segu; (9) Semengoh Reserve; (10) Mt Santubong;
(11) Gunong Mulu Natl Pk; (12) Lungmanis; (13) Sepilok Reserve; (14) Sibuga Forest; (15) Quoin Hill
Res. Stn; (16) Umas Umas; (17) Mt Makihng; (18) Quezon City; (19) near Dumaguete; (20) Dumoga-
Bone Natl Park.

Sixteen of the 26 named Old-World species have been described since the tribe Basicerotini
was estabUshed and first monographed by Brown & Kempf (1960).

I have previously published and supplemented a review of the Melanesian and Australian
species (Taylor 1968, 1970, 1980). No additional species or significant distributional records
are known from these areas.

New Asian Ants of the Basicerotini 399

Materials and Methods

The descriptions and key published here were prepared with Delta system software (Dallwitz 1980;
Partridge et al. 1988) using a Bondwell (Model 8) portable lap top computer, and the accompanying
micrographs were prepared using a JEOL JSM4 scanning electron microscope. For each species, the
standard illustrations include a frontal view of the head, a dorsal view of the mesosoma and waist
nodes, and a lateral view of the whole animal. All depict holotype specimens. Comparable micrographs
have been published previously for Rhopalolhrix orbis by Taylor & Beaton (1970), for Eurhopalothrix
emeryi, E. hoplites, E. insidiatrix and E. szentivanyi by Taylor (1980), for E. heliscata by Wilson &
Brown (1984), and for E. biroi (in part) by Holldobler & Wilson (1986).

The conventions for measurements and indices follow Brown & Kempf (1960) and Taylor (1968).
In brief, head length (HL), head width (HW), pronotum width (PW) and postpetiole width are
maximum measurable dimensions of the subject structures in square dorsal view; mandibular extension
(MI) is the long-axial distance from the level of the anteriormost point of the clypeus to the tip of the
closed jaws, in HL measuring position; scape length (SL) is the maximum distance from the apex of
the scape to the tip of its basal lobe; Weber's length of the mesosoma (WL) is measured in side view,
as the direct line from the anterior face of the pronotum to the inferior propodeal angle, on a plane
where both are in microscopic focus. The indices are calculated percentages, as follows: CI = HW%HL,
MI = ML%HL and SI = SL%HW.

Discussion

Collecting Basicerotine Ants

All but one of the specimens of the new species described here were collected from soil
or leaf htter using Berlese funnels, Winkler bags or soil cores. In 5 weeks of collecting in
West Malaysia and Borneo in 1968, I took several hundred specimens of 7 species (all of
them new to science) using portable, electrically powered Berlese funnels. During that
expedition, no specimens at all were collected by hand. Knowledge of the Neotropical and
Australasian species is also based largely on mechanically collected specimens. Because
of the small size and cryptobiotic nature of these ants, it is very difficult to collect them
by hand.

Species Distribution and Sympatry

Several of the species described here are widely distributed, notably E. omnivaga,
E. corona ta and E. philippina (Fig. 1). Such distributions seem to be frequent among
cryptobiotic S.E. Asian ants which inhabit rainforest leaf litter. Further examples are
provided by Dacetinops (see Taylor 1985), where 3 of the 4 Asian species are known at
least from southwestern Sarawak and northeastern Sabah. One of these (D. concinnus
Taylor), is found also near the southern tip of Borneo, and another (D. cirrosus Taylor),
in northern peninsular Malaysia. All 4 species are sympatric at Semengoh Forest Reserve,
c. 19 km S.W. of Kuching, western Sarawak, the only known collection locality for one of
them {D. wilsoni Taylor). The other 3 (£). cirrosus, D. concinnus and D. solivagus Taylor)
are widely sympatric elsewhere, including localities in Sabah.

Known sympatric associations among the Eurhopalothrix species discussed here are
summarised in Fig. 1. Judging from the records, E. omnivaga is associated in some part of
its range with every other known Malaysian species. The other species described here from
Malaysia are each known to be directly sympatric with 2 others (including E. omnivaga),
except for E. rothschildi, which has been taken only with E. omnivaga.

On the other hand, the 3 apparently closely related species of the E. platisquama
group are allopatrically distributed: E. platisquama in peninsular Malaysia and Sumatra,
E. seguensis in eastern Sarawak, and E. dubia in Sabah.

Basicerotine Phytogeny

Beyond the Indo-Australian area, the tribe Basicerotini is represented in the Neotropical
and southern Nearctic realms by several genera and a number of species, including 11
described in Eurhopalothrix and 6 in Rhopalothrix (Brown & Kempf 1960; Kempf 1962,
1967; SneUing 1968; Brown 1974, 1980a, 19806). Additional undescribed species are known
in Eurhopalothrix (R. R. SneUing, personal communication).

400 R. W. Taylor

For several reasons the tribe seems especially suitable for phylogenetic analysis. Some of
its Neotropical genera are bizarre and apparently highly autopomorphic (including Aspididris
Weber, Basiceros Schulz, Creightonidris Brown, Protalaridris Brown, and Talaridris); their
relationships are worthy of investigation. In addition the affinities between species currently
placed in the 'main line' genera Octostruma Forel, Eurhopalothrix and Rhopalothrix, need
clarification. Aspididris was considered a synonym of Basiceros by Brown (1974). It is
possible that the present generic arrangement needs further amendment.

Most interesting in the present context is the fact that Eurhopalothrix and Rhopalothrix
are present on both sides of the South Pacific; that their two major biogeographic com-
ponents must have been long separated; and that they both, nonetheless, have largely parallel
sets of interspecifically varying characters, which range similarly in both groups. Analysis
of this variability in these two major biogeographic components, considered together and
separately for comparison, could provide information of special phylogenetic interest, and
could clarify understanding of possible evolutionary patterns in the light of the major
biogeographic separation involved. It appears that there must have been some homoplasy
in the separate evolution of the two geographical components in each genus, but some
of the patterns of variability are likely to have been established before the taxa were
geographically fragmented, in which case substantial evolution of their diverse morphology
could have occurred in a single radiation prior to separation, or have been programmed
by events which preceded the geographical split.

Other interesting questions involve analysis of the trans-South Pacific geographical links,
whether 'northern' or 'gondwanic', especially considering the richness of Eurhopalothrix in
Papuasia, as opposed to Australia, and the fact that Rhopalothrix, with a species each in
Australia and New Guinea, is unknown from S.E. Asia.

The matters discussed above can be briefly exemplified by considering the numbers
and distribution of the specialised large cephalic hairs of various Eurhopalothrix species.
The following conditions are present in both trans-Pacific faunas:

(a) The presence of relatively high numbers of specialised cephalic hairs arranged in
3 transverse rows, an anterior transocular series, an intermediate series, and an occipital
series (Fig. 8). In the neotropics the following numbers of hairs are known respectively in
these ranks: 8:4:8 {E. gravis Mann), and 6:4:8 (£. lenkoi Kempf, and 3 other species in
figs 36-38 of Brown & Kempf; 1960). In the Indo-Austrahan fauna the combination 10:4:4
is known in E. australis, and 8:4:4 in E. brevicornis, E. caledonica and E. coronata. It is
notable that an occipital row of 4 hairs (v. 6 or 8) appears to characterise the palaeogean
species.

{b) The presence of 4 hairs clustered in a tight square array at the midline near the
occipital margin, with or without 1 other pair elsewhere on the head (Figs 13-15). [E.
speciosa Brown & Kempf and E. apharagonia Snelling in the New World; two of the three
E. platisguama-groxxp species and E. emeryi (less distinctly so) in the Old.]

(c) The presence of only a single pair of frontal hairs, as in E. omnivaga (Figs 1A-I(s).
This condition is found in E. floridana Brown & Kempf in the Americas, and in several
species in the Indo-Austrahan fauna.

(d) Both faunas include species which entirely lack enlarged, specialised cephalic hairs,
including the South American E. bruchi (Santschi) and the Papuasian E. punctata, and
E. hoplites.

In addition, various intermediate conditions are known, especially in the Indo-Australian
fauna.

Similar considerations apply to other features, including the distribution of specialised
pilosity elsewhere on the body, the details of specialisation in the structure of the hairs
themselves [a wonderful subject for scanning electron microscopy, see Figs 11-12 (a stereo-
scopic pair), 33, 34], sculptural details, mandibular structure and dentition, etc.

The species of Rhopalothrix show variation similar to that of Eurhopalothrix. For
example, the Neotropical R. ciliata Mayr has 2 rows of transverse enlarged hairs on the
frons, with the formula 12:4, but this is clearly derived from 8:4:4. The other neogean
species lack enlarged, specialised cephalic hairs. The formulae 8:4:4 and 10:4:4 are repre-

New Asian Ants of the Basicerotini 401

sented in the Australian species (JR. diadema and R. orbis). There are remarkable overall
similarities in post-mandibular structure between the last 2 species and Eurhopalothrix
coronata, such that close relationship between them seems tenable, implying that Rhopalo-
thrix, as presently conceived, could be at least biphyletic, with the included palaeogean and
neogean species separately derived from Eurhopalothrix-like ancestry.

Repositories

Specimens studied here are from the Australian National Insect Collection, CSIRO, Canberra
(ANIC), the British Museum (Natural History), London (BMNH); and the Museum of Comparative
Zoology, Cambridge, Mass. USA (MCZC). Abbreviations for other collections in which types have
been deposited are:

BPBM B. P. Bishop Museum, Honolulu, Hawaii, U.S.A.

LACM Los Angeles County Museum of Natural History

MHNG Museum d'Histoire Naturelle, Geneva, Switzerland

MKUB Sarawak Museum, Kuching

MKUC Masao Kubota collection, Odawara City, Japan

I collected most of the specimens, and am designated RWT in the record lists. Geographical
coordinates are given for all listed type localities, and for most other localities at their points of first
appearance in the text.

Interactive Computer Key to the Palaeogean Basicerotine Ants

Computer software able to generate an on-line interactive key to all known palaeogean species of
basicerotine ants has been developed as part of this project. Copies of the data base and operating
system are offered to applicants on floppy or microfloppy discs suitable for use with personal
computers. Details are available from the author.

Key to the Old-World Species of Tribe Basicerotini (Workers)

The known queens of Asian Eurhopalothrix species run through the key consistently with their
workers. They represent E. dubia, E. heliscata, E. jennya, E. omnivaga and E. procera.

1 . Mandibles linear, their insertions remote, so that the masticatory borders cross or engage only

near their apices (genus Rhopalothrix) 2

Mandibles triangular, their whole serially dentate masticatory borders engaging directly at full
closure (genus Eurhopalothrix) 3

2. Specialised large hairs on cephalic dorsum numbering 16, with 8 in anterior row (super-

numerary hairs may occur; Taylor 1970); hairs on disc of first gastral tergite of one size
class; mesosomal dorsum with a distinct transverse metanotal impression, the propodeal
dorsum a transverse tumosity behind it; propodeal teeth well developed, forming angles
of about 90° in side view (E. Australia — S.E. Queensland, N.E. New South Wales) ....

R. orbis Taylor

18 specialised hairs on cephalic dorsum, with 10 in anterior row; hairs of first gastral tergite
of 2 size classes; metanotal impression feeble; propodeal dorsum sloping back abruptly

towards declivity; propodeal teeth only obtuse vestiges (N.E. New Guinea)

R. diadema Brown & Kempf

3(1). S.E. Asian and Philippines species found to the west of New Guinea 4

Melanesian, Australian and Pacific species 15

4(3). Sides of mesosoma behind pronotum smooth and shining (Fig. 37), essentially unsculptured

(widespread in Indo-Pacific area) E. procera (Emery)

Sides of mesosoma behind pronotum dull, distinctly sculptured, usually with large shallow
pit-hke 'thimble punctures' separated by about 0-5-1 x their average diameter (Figs 10,
29); alternatively (in 1 Philippines species) these surfaces are densely and moderately
coarsely punctate-shagreened (Fig. 7) 5

5(4). Punctures of frons and most dorsal body surfaces each filled by a flat-surfaced, feather-edged,

metallic silvery hair (Figs 30-34); this exceptional ground pilosity often largely contiguous,
especially on the frons; eyes relatively large, with about 16-20 facets, maximum diameter

close to that of a funicular club (E. platisquama group) 6

Hairs of ground pilosity not as above, usually very reduced, sparse, or both, never squamous
or silvery-metallic; eyes either absent or much smaller, usually with fewer than 10 facets

402 R. W. Taylor

6(5). Four erect, narrowly clavate hairs, separated by about their average length, clustered in a

square array on the frons, at the midline near the occipital border (Figs 13-15). (Other

similar hairs may be present elsewhere on the head) 7

A single pair of laterally adjacent hairs in the position described, with another hair close to
the occipital border on each side, about midway between the median pair and the posterior
occipital angle (Figs 41-43) (Sarawak) E. seguensis, sp. nov.

7(6). Frons with a single erect hair on each side about mid-way between the posteromedian cluster

and the ipsilateral eye (Figs 13-15) (Sabah) E. dubia, sp. nov.

Frons lacking erect hairs apart from those of the posteromedian cluster (Figs 30-33) (W.
Malaysia, Sumatra) E. platisquama. sp. nov.

8(5). Frons with 6 or more erect, clavate, or ornately specialised large hairs 9

Frons with only a single pair of large erect, simple, clavate hairs, situated on its postero-
median sector 10

9(8). Enlarged hairs of frons globular, prominent and strikingly creamy-white; 16 in number in

3 transverse rows; the anterior, transocular, row with 8 hairs, the others each with 4;
ground pilosity of first gastral tergite prominent, its hairs virtual miniature versions of the
enlarged globular hairs which accompany them (Figs 8-12, 46) (Sarawak, Sabah, Sumatra)

E. coronata, sp. nov.

Enlarged cephalic hairs erect, slender, only slightly clavate and relatively inconspicuous,
golden-brown in colour; 6 in number, 4 apparently the remnants of a transocular row,
and 2 behind them placed near the median occipital border. Ground pilosity of gaster fine
and inconspicuous (Figs 16-18, 48) (Sarawak) E. jennya, sp. nov.

10(8). Posterior occipital angles obsolete, occipital border broadly arched between the lateral occipital

angles, which form the lateral extremities of the cranium (Fig. 27) (Philippines)

E. philippina Brown & Kempf

Posterior occipital angles well developed, though sometimes very obtuse, the occipital border
between them broadly concave (Figs 2, 19) 11

11(10). Larger species (HW across lateral occipital angles >l-0 mm) (E. heliscata group)

12

Smaller species (HW<0-78 mm) 13

12(11). Petiolar node in dorsal view distinctly longer than broad; a relatively coarsely sculptured
species with prominent ground pilosity on frons, promesonotal dorsum, petiole and
postpetiole; pro- and mesonotal sections of promesonotum separated by a more-or-less

distinct transverse trough (Figs 19-22, 49) (W. Malaysia)

E. heliscata Wilson & Brown

Petiolar node in dorsal view approximately square, its length and breadth subequal; overall
less heavily sculptured, with scattered, diffuse, sparse ground pilosity of small fine hairs,

not concentrated as described above (Figs 5-7, 23, 45) (Luzon, Philippines)

E. chapmani, sp. nov.

13(11). Outer borders of mandibles distinctly concave, basal borders oblique, framing a narrowly
transverse triangular gap against the anterior clypeal border when the jaws are closed
(Fig. 24); larger species (HW>0-63 mm) (widespread: Perak to Sumatra, Sarawak, Sabah

and Sulawesi) E. omnivaga, sp. nov.

Outer borders of mandibles more-or-less evenly convex; posterior borders closing tightly
against clypeus, without an intervening gap (Fig. 2); smaller species (HW<0-59 mm)
(northern Borneo) 14

14(13). Petiolar node distinctly longer than wide in dorsal view (Fig. 3) (Sabah)

E. browni, sp. nov.

Petiolar node distinctly transverse in dorsal view (Fig. 39) (Sarawak)

E. rothschildi, sp. nov.

15(3). Mandibles with a broad, low basal tooth, approximately twice as wide at base as the
succeeding teeth; erect clavate hairs (except those on gastral apex) restricted to a single

pair on verticocciput; HW 0-72-0-89 mm 16

Mandibular teeth conical, subsequal in size throughout; erect clavate hairs usually not
distributed as above; size frequently different 17

16(15). Propodeal teeth well developed, supporting broad infra-dental lamellae, a triangular area of
propodeal dorsum anterior to their bases distinctly concave and more-or-less clearly set
off from the remaining dorsum; colour medium-dark reddish brown (Solomon Is., Ysabel

and Vella Lavella) E. isabellae (Mann)

Propodeal teeth vestigial, surmounting very narrow infra-dental lamellae; propodeal dorsum
almost entirely convex, with at most only slight traces of a posteromedian concavity;
colour bright golden chestnut-brown (Manus Island) E. cinnamea Taylor

New Asian Ants of the Basicerotini 403

17(15). Smaller species, HW<0-75 mm 18

Larger species, HW>0-93 mm 22

18(17). Posterior third of head covered thickly with conspicuous, white, orbicular squamiform hairs
(including the specialised hairs, which are only weakly differentiated in this species);
pilosity of anterior two-thirds of head abruptly reduced to fine, minute vestiges, this

area appearing naked by contrast (N.E. New Guinea) E. biroi (Szabo)

Pilosity of head otherwise; either reduced throughout or without an abrupt difference between
anterior and posterior sections; specialised larger hairs, when present on dorsum of head,
strongly differentiated and more-or-less clavate 19

19(18). Specialised erect hairs of head absent (N.E. New Guinea) E. punctata (Szabo)

Specialised erect hairs of head, when complement is complete, numbering 16-18, arranged
in 3 transverse rows 20

20(19). Larger species (WL>0-65 mm); dorsal face of propodeum with an angular impression or

'step' at its midlength (New Caledonia) E. caledonica Brown & Kempf

Smaller species (WL<0-65 mm); dorsal face of propodeum forming an evenly concave slope
21

21(20). Very small species (WL<0-52 mm); clypeus divided by a transversely arched carina;
head with 16 large erect hairs, with 8 in the anterior row (New Guinea, New Britain,

Guadalcanal) E. brevicornis (Emery)

Slightly larger species (WL>0-52 mm); head with 18 or more large erect hairs, with 10 in
the anterior row (apparently anomalous specimens have been reported with 11 or 12 hairs
in the anterior row; Taylor 1970) (eastern Queensland and New South Wales, S. at least
to lat. 30°) E. australis Brown & Kempf

22(17). Mandibles broadly triangular, their posterior borders closing directly against the clypeal

border, outer borders usually convex, feebly concave in 1 species 23

Mandibles narrowed, posterior borders oblique, so that a large semicircular space is left
between them and the anterior clypeal border at full closure, outer borders distinctly
concave (N. New Guinea) E. szentivanyi Taylor

23(22). Posterior angles of occipital lobes in full-face view very distinctly acute; head, mesosoma
and nodes coarsely rugose; posterior sides of mesosoma covered with coarse diagonal
costation; first gastral tergite, except for a narrow median strip, uniformly covered with
conspicuous, subreclinate, squamiform hairs (larger hairs differentiated in queens, but

not in workers); HW>l-33 mm (Fiji Is) 24

Posterior occipital angles slightly obtuse or at most very feebly acute; body variously
sculptured, but never so extensively rugose; posterior sides of mesosoma nearly smooth,
at most feebly punctate or shagreened, and usually more-or-less shining; first gastral tergite
with ground pilosity minute, sparsely and unevenly distributed, or obsolete, 1 or more
pairs of erect clavate hairs often present on its disc; HW only rarely exceeding 1 • 30 mm
25

24(23). Frons rugose, the individual rugae more-or-less straight, transverse posteriorly, and longi-
tudinal above the eyes, but diverging on each side posteriorly, to form a triangular figure
around the centre of the head; a strong transverse series of rugae on and behind the

nuchal collar E. emeryi (Forel)

Frons coarsely rugo-reticulate; virtually no straight rugae either on head or nuchal collar;

the frontal rugae so dense and strong that the spaces between them are pit-hke

E. insidiatrix Taylor

25(23). CI of holotype 102; specialised erect hairs lacking except on the leading edges of scapes and

at gastral apex; mesosomal profile a more-or-less evenly convex arc

E. hoplites Taylor

CI 106-114; a pair of erect specialised hairs at least on the verticocciput and pronotum;
mesosomal profile biconvex 26

26(25). Ventral profile of petiole finely serrate; first gastral tergite with up to 8 erect clavate hairs
arranged in 2 longitudinal rows; head and promesonotum with similarly intense sculpturing
(widespread, ranging from Asia to Samoa and N. Queensland) .... E. procera (Emery)
Ventral profile of petiole without serrations; first gastral tergite without erect clavate hairs;
head smooth, with scattered medium punctures, contrasting strongly with the coarsely
rugo-reticulate promesonotum (Guadalcanal, Solomon Is) E. greensladei Taylor

Descriptions of New Species

Shared Attributes

The species described below share a number of attributes, which are itemised here to

404 R. W. Taylor

avoid repetition in individual descriptions. Alternative conditions are represented in other
Indo-Australian species. Two classes are recognised:

Class A attributes are present in all 9 species; they include:

(1) Mandibular teeth conical, similar throughout in size and shape, the basal member
of each series much like the others, not expanded or blade-hke.

(2) Frons lacking pronounced bilateral tumosities between or behind the levels of the
eyes (or their usual position if they are lacking), its widest part more-or-less evenly arched-
convex when viewed tangentially from behind, with at most only traces of tumose swellings.

(3) Posterior occipital angles either approximately right-angled or distinctly obtuse,
always exceeding 80° in frontal view.

(4) Promesonotal dorsum barely raised, if at all, above the propodeal dorsum, its dorsal
outhne in side view much less than semicircular.

(5) Propodeal dorsum a more-or-less even, posteriorly directed slope.

(6) Sculpturation rather uniform throughout.

(7) Sides of mesosoma sculptured similarly to its dorsum, often more finely so, and
lacking extensive smooth shining areas.

(8) Ground pilosity of posterior third of face generally similar to that of anterior j.

(9) The colour in all species is dull medium or reddish-brown, with the speciaUsed
enlarged hairs and ground pilosity light in colour, ranging from creamy-white to golden-
brown, depending on the species.

Class B attributes are found in most of the new species, unless otherwise indicated in the
relevant descriptions. They include:

(1) Outer mandibular borders in frontal view partly straight or concave, not entirely
convex.

(2) Posterior borders of mandibles closing directly against the clypeus, without an
intervening gap.

(3) Face of clypeus between frontal lobes more-or-less planar, without a transverse
ridge.

(4) Mesosomal profile a continuous curve, not interrupted at the promesonotal/
propodeal junction by a notch or step in the level of the outline.

(5) Metanotal groove lacking, either as an incised line or as a distinctly deUmited trench.

(6) Head, mesosomal dorsum, nodes and gaster coarsely and closely punctate (with
sculpturation of the type sometimes referred to as 'thimble-Uke')-

Several species (which constitute the group of E. platisquama) have ground pilosity
of remarkable large, squamous, silvery hairs, with tessellated, feather-down-like margins
(Figs 33, 34). These are densely arrayed on the frons and other dorsal body surfaces
(Figs 30-32). These hairs are unhke any described previously for basicerotine ants, which
are notable for their frequently aberrant, even eccentric pilosity (Holldobler & Wilson 1986).

E. browni, sp. nov.
(Figs 2-4, 44)
Type Locality

Malaysia: Sabah: Lungmanis, mile 45 (Labuk Rd, ex Sandakan) (05°52'N.,118°04'E.).

Distribution, Type Deposition

Known only from the unique worker holotype, collected from berlesate, rainforest leaf mould
(RWT ace 68.502, 12-13. vi. 1968). In ANIC (type No. 7775); the specimen gold-palladium coated for
SEM study.

Named for Professor W. L. Brown Jr, of Cornell University.

Worker

General features as illustrated. All Class A attributes present, with those of Class B,
unless otherwise indicated. Dimensions (mm): HL 0-50; HW 0-53; CI 106; ML 0-12;
MI 24; SL 0-29; SI 55; PW 0-29; WL 0-56. Eyes either lacking or imperceptibly minute.

New Asian Ants of the Basicerotini

405

Face of clypeus between frontal lobes divided by an almost vestigial low, transverse welt.
Frons spanned by a slightly arched, shallowly depressed groove emanating on each side at
about the normal position of the eye; bordered anteriorly by a conspicuous transverse welt.
Occipital border broadly and distinctly emarginate (its outline comparatively somewhat 'V
shaped; not an even arc); occipital angles approximately right angular. Mesosomal profile
almost a continuous curve, but interrupted at the promesonotal/propodeal junction by a
minute, very feebly indented notch. Metanotal groove weakly incised dorsally as a distinct
trench which more-or-less severs the surrounding sculpture. Petiolar node in dorsal view
distinctly longer than wide. Specialised enlarged hairs lacking on promesonotum, petiole and
postpetiole, represented only be one pair on the frons (one hair has been lost from the
holotype); the remaining hair clavate, expanded to about j its maximum height, well

Figs 2-4. Eurhopalothrix browni, holotype worker, standard views, see description for dimensions.

406

R. W. Taylor

differentiated from the minute ground pilosity. Several such hairs at least are probably
normally present on the dorsal surface of first gastral tergite, where the holotype has a
single, unpaired, club-shaped mediolateral hair. Ground pilosity minute, scattered, moderately
prominent on gastral dorsum.

E. chapmani, sp. nov.
(Figs 5-7, 23, 45)
Type Locality

Philippines: Luzon: Ateneo De Manila, Quezon City (14°38'N.,121°02'E.).

r

r

^^ ' "'^^^^^^^^^H

p

r

1

y%r-v^-'-

■'■'■.x^M^k

^^^fc"-

^|k:

Figs 5-7. Eurhopalothrix chapmani, holotype worker, standard views, see description for dimensions.

New Asian Ants of the Basicerotini 407

Distribution, Type Deposition

Known only from the unique worker holotype, collected from the base of a rotten pole in a bamboo
thicket (B. B. Lowery, 8.vii.l978). In ANIC (type No. 7776); the specimen gold-palladium coated for
SEM study.

Named for the late American Philippines teacher and myrmecologist James W. Chapman.

Worker

General features as illustrated. All Class A attributes present, with those of Class B,
unless otherwise indicated. Dimensions (mm): HL 1-01; HW 1-05; CI 104; ML 0-29;
MI 29; SL 0-64; SI 62; PW 0-61; WL 1-21. Outer mandibular borders in frontal view
broadly and more-or-less evenly convex. Eyes rather small, with 6-8 facets. Posterior
occipital angles approximately 90°. Promesonotal profile almost straight, very shallowly
and broadly depressed about the mesonotal/propodeal junction. Propodeal dorsum only
slightly depressed posteriorly between the bases of the teeth.

A single pair of speciahsed erect hairs (one of which has been lost by the holotype)
bilaterally near the midline on posterior part of frons, the hairs small and only slightly
clubbed. Similar hairs on last 3 exposed gastral sternites, and posteromedially on first
tergite; otherwise lacking. Pubescence reduced, its hairs small and scattered, except on
posterior part of frons, occipital lobes, and dorsa of pronotum, petiole and postpetiole.

Resembling E. heliscata Wilson & Brown, 1984; with the following salient differences:

(1) Sculpturation finer and less strongly delimited, as follows:

Mandibles coarsely punctate with shining interspaces, somewhat rugose at their bases.
Head, mesosoma and nodes moderately finely punctate-shagreened (unlike other species
described here), sculpturing less sharply defined elsewhere on mesosomal dorsum, and
especially on waist nodes; frons and pronotal dorsum tending to be more rugulose, though
very finely so; gastral dorsum slightly more finely sculptured than elsewhere.

(2) Generally less 'craggy' in appearance (compare Figs 5-7 with 19-21). Surfaces of
frons and occipital lobes smoothly rounded, where in E. heliscata the frons has a transverse
anterior tumosity behind the broadly depressed fronto-clypeal suture, relatively strong
swellings under each of the two enlarged cephalic hairs, and the apices of the frontal lobes
are somewhat more abruptly swollen anteriorly. Postpetiolar dorsum almost entirely convexly
curved, with a relatively featureless surface, where in E. heliscata its disc is more-or-less
flattened anteromedially, and somewhat depressed behind the slightly raised rim-like anterior
edge; the posterior portion of the dorsum is bitumose when viewed obUquely along the
long-axis of the body, with a shallowly depressed median channel running back from the
anteromedian section.

(3) Pronotal dorsum a transversely even arch, where in E. heliscata it is distinctly
bitumose in transverse profile.

(4) Petiolar node in dorsal view about as long as wide, v. distinctly longer than wide
in E. heliscata.

E. chapmani seems to be close to E. heliscata as implied above, and both species are
probably related to E. procera (compare Figs 5-7, 19-21, and 35-37).

E. coronata, sp. nov.
(Figs 8-12, 46)
Type Locality

Malaysia: Sabah: Quoin Hill Research Station, near Tawau (04°16'N.,117°54'E.).

Distribution, Material Examined

Malaysia: Sarawak: First Division: Kampong Segu, near Kuching, 1 paratype worker (RWT ace
68.249, 4.iv.l968); Sabah: Quoin Hill Research Station, (type locality), 750 ft, holotype worker
(RWT ace 68.614, 16-69 vi.l968); Indonesia: Sumatra: Liwa (05°04'S.,104°03'E.), 1 paratype worker
(M. S. Harvey, 5.ix.l984). All specimens from Berlese funnel or Winkler bag extractions of rainforest
leaf mould.

R. W. Taylor

iv^■■*

Figs 8-12. Eurhopalothrix coronata, holotype worker; 8-10, standard views, see description for
dimensions; 11, 12, details of cephalic pilosity (right inner enlarged hairs and adjacent enlarged
pubescence) — stereoscopic pair, scale line 20 ^.
Figs 11, 12. Eurhopalothrix coronata, holotype worker, standard views, see description for dimensions.

New Asian Ants of the Basicerotini 409

Type Deposition

All types in ANIC (type No. 7777). The holotype gold-palladium coated for SEM study.

Worker

General features as illustrated. All Class A attributes present, with those of Class B,
unless otherwise indicated. Dimensions (holotype, mm): HL 0-51; HW 0-50; CI 102;
ML 0-09; MI 21; SL 0-30; SI 60; PW 0-25; WL 0-50. Both the paratypes have HW
0-52 mm. Outer mandibular borders more-or-less continuously (feebly) convex in frontal
view. Face of clypeus between frontal lobes divided by a relatively very distinct, obtuse,
transversely arched ridge. Eyes small but distinct, 4- or 5-faceted. Occipital border broadly
but shallowly emarginate, the outline an even arc. Mesosomal profile not a continuous
curve, its outline shallowly depressed at the promesonotal/propodeal junction; mesometanotal
suture, however, represented only as a narrow depression without an incised groove severing
the underlying sculpture. Petiolar node in dorsal view distinctly wider than long.

Specialised enlarged hairs well differentiated from those of ground pilosity; each globose,
expanded at about half its height, with a relatively thick basal stem. Distributed (when
complement is complete) as follows: 16 on frons, in 3 transverse rows. The middle and
posterior rows each with 4 hairs, the anterior with 8; 2 pairs on promesonotum (lateral
and posterolateral), and a single posterolateral pair each on the petiolar node and post-
petiole. About 18 such hairs on dorsum of first gastral tergite, arranged roughly in 4
longitudinal rows of 4, 5, 5 and 4. The accompanying scattered hairs of the ground pilosity
relatively large, about j to j the height of the specialised major hairs, and generally of
similar structure, but relatively a little less inflated; ground pilosity elsewhere well developed,
as illustrated.

E. dubia, sp. nov.
(Figs 13-15, 47)
Type Locality

Malaysia: Sabah: Umas Umas, near Tawau (04°16'N.,117°54'E.).

Distribution, Material Examined

Malaysia: Sabah: Lungmanis, mile 45 (Labuk Rd, ex Sandakan), 4 paratype workers (RWT aces
68.475, 502, 12-13.vi.l968); Sepilok Forest Reserve, near Sandakan (05°52'N.,118°04'E.), paratype
worker (RWT ace 68.451, 12. vi. 1968); Umas Umas (type locality), holotype, 7 paratype workers, 2
paratype queens (RWT aces 68.626, 627, 12-13. iv. 1968). All specimens from Berlese funnel extractions
of rainforest leaf mould.

Type Deposition

Holotype and paratypes in ANIC (type No. 111%), holotype gold-palladium coated for SEM study.
Worker paratypes in BMNH, MCZC, MKUB.

Worker

General features as illustrated. All Class A attributes present, with those of Class B,
unless otherwise indicated. Dimensions (holotype, mm): HL 0-69; HW 0-74; CI 107;
ML 0-17; MI 25; SL 0-40; SI 54; PW 0-44; WL 0-78. The smallest (Umas Umas) and
largest (Lungmanis) paratypes have HW 0-73 and 0-85 mm respectively. Occipital border
almost straight, transverse [its outline at most minutely curved (usually concave) or sinuate].
Petiolar node in dorsal view essentially square, with its length and breadth subequal, to
distinctly but moderately wider than long.

Frons and clypeus almost entirely, and other dorsal body surfaces extensively, covered
by a ground pilosity of dense, flattened, thoroughly appressed, squamous, shining silvery
hairs, which are almost contiguous and fill or overlap the punctures bearing them. These
hairs with feathered margins under SEM examination. Specialised erect hairs also present,
well differentiated from those of the ground pilosity. Each clavate, barely expanded, though
relatively thick and columnar; distributed (when complement is complete) as follows: 6 on
frons: 2 pairs grouped posteromedially at the occipital border in a tight square array (the

410

R. W. Taylor

hairs spaced by about their average length); the other 2 hairs each midway between this
group and the ipsilateral eye. Such hairs lacking on promesonotum and petiolar node, and
on dorsum of first gastral tergite; one pair (posterolateral) on postpetiole. Ground pilosity
of scapes and legs dense, generally less specialised than on body, though squamous hairs
are present on the antennal scapes and humeral knees.

Queen

General features as in the worker, with the usual differences of full alate sexuality.
Specialised hairs of head and postpetiole as in worker. Additional such hairs (maximum

Figs 13-15. Eurhopalothrix dubia, holotype worker, standard views, see description for dimensions.

New Asian Ants of the Basicerotini

411

known complement; apart from those at the gastral apex) as follows: 2 pairs (relatively
slender), well separated, on anterior disc of scutum; thicker hairs on each side on postero-
lateral extremities of scutum, and on disc of scutellum; 8 slender hairs in 2 longitudinal
rows on first gastral tergite.

Figs 16-18. Eurhopalothrix jennya, holotype worker, standard views, see description for dimensions.

412

R. W. Taylor

.Sij> ■ S ■ .■'■; .-

tSR^^kiBLr'"*

ii i

■■■ 't-iW.m

Figs 19-23. Eurhopalothrix heliscata Wilson & Brown, paratype worker (Sungei Menyala Forest
Reserve, Negeri Sembilan. W. Malaysia; ANIC); 19-21, standard views, HW 1-11 mm; PW 0-59 mm;
WL 1-20 mm; 22, details of cephalic sculpturing, near left eye (visible at right), scale line 20 ^.
23, Eurhopalothrix chapmani holotype worker, details of sculpturing near apex of left occipital lobe,
scale as for Fig. 22.

New Asian Ants of the Basicerotini 413

E. jennya, sp. nov.
(Figs 16-18, 48)
Type Locality

Malaysia: Sarawak: First Division: Kampong Segu, 20 miles S.W. of Kuching (Or33'N.,110°20'E.).

Distribution, Material Examined

Malaysia: Sarawak: Forest Division: Kampong Segu, holotype, 15 paratype workers, 2 paratype
queens (RWT aces 68.289, 291, 292, 4.vi.l968); Fourth Division: Gunong Mulu National Park, near
Marudi (04°15'N.,1 14°19'E.), 21 paratype workers (P. Hammond, J. E. Marshall, v-viii.l978); (Long
Patau), 4 paratype workers (B. Bolton, 2.ix.l977). All samples from lowland rainforest, usually from
leaf litter berlesates.

Named for my friend Jenny Rothschild, formerly of Semengoh Research Station, near Kuching,
Sarawak. The name should be considered a noun in apposition.

Type Deposition

Holotype and most paratypes in ANIC (type No. 7779); holotype gold-palladium coated for SEM
study. Paratypes in BMNH, LACM, MCZC, MKUB, MKUC.

Worker

General features as illustrated. All Class A attributes present, with those of Class B,
unless otherwise indicated. Dimensions (mm): HL 0-57; HW 0-61; CI 106; ML 0-16;
Ml 28; SL 0-33; SI 54; PW 0-37; WL 0-66. The Kampong Segu paratypes have HW 0-59-
0-63, and those for Gunong Mulu 0-58-0-63. Eyes minute, with 4 to 6 facets. Occipital
border broadly, distinctly, but relatively shallowly emarginate. Petiolar node in dorsal view
essentially square, its length and breadth subequal.

Specialised enlarged hairs well differentiated from those of the ground pilosity. Each
clavate, expanded to about j its height. Distributed (when complement is complete) as
follows: 3 pairs on frons, where the hairs are well dispersed; 4 frame a large transverse,
posteromedian rectangle (the posterior pair dividing the occipital border approximately
into thirds), with one on each side immediately behind the eye. In effect the head has 2
transverse rows, the anterior of 4 hairs, the posterior of 2, with the latter each aligned
longitudinally with one of the median anterior hairs. Promesonotum with an erect dorso-
lateral hair on each side, at about its mid length (one or both of these hairs is frequently
missing from specimens). One pair (posterolateral) on petiolar node (missing from holotype),
and 6 on dorsal surface of first gastral tergite, arranged in 2 longitudinal rows of 3 [one
K. Segu paratype has a 4th hair (? supernumerary) on one side]. None of the type workers
has posterolateral erect hairs on the postpetiole, similar to those of the queen (see below).
Slight impressions in the appropriate positions imply that these have been present, but were
lost in all specimens examined. The equivalent postpetiolar hairs in other species seem to be
more deciduous than those in other positions. Ground pilosity of minute scattered hairs is
moderately dense on all dorsal body surfaces, scapes and legs.

Queen

General features as in the worker, with the usual differences of full alate sexuahty.
Speciahsed hairs of head and petiole as in worker. Additional such hairs on the 2 available
specimens (apart from those at the gastral apex) as follows: 1 pair at posteromedian border
of pronotum; 2 pairs (relatively short and slender) in 2 longitudinal rows on disc of scutum;
2 pairs placed respectively laterally and posterolaterally on margin of scutum; a pair laterally
on scutellum; and a posterolateral pair on postpetiole. Twelve hairs are scattered on the first
gastral tergum, loosely arranged in 4 longitudinal rows.

E. omnivaga, sp. nov.
(Figs 24-26, 50)
Type Locality

W. Malaysia: Selangor: Ulu Gombak Field Station, near Kula Lumpur (03°08'N.,10r42'E.).

414

R. W. Taylor

Distribution, Material Examined

W. Malaysia: Perak: Cameron Highlands (Sungei Simei Falls), 11 worker paratypes, 1 queen
paratype (T. Jaccoud & P. Marcuard, 25-28.iii.1977); Selangor: Ulu Gombak Field Station (type
locality), holotype 16 worker paratypes, 2 queen paratypes (RWT aces 68.785, 788, 848-9, 851,
1 1-14. vii. 1968); 3 worker paratypes (B. Bolton, 7.x. 72); Upper Gombak Valley, worker paratype
(D. H. Murphy, 9.ii.l967); 1500 ft, 7 worker paratypes (RWT ace 68.848, 13.vii.l968; 10 km E. of

Figs 24-26. Eurhopalothrix omnivaga, holotype worker, standard views, see description for dimensions.

New Asian Ants of the Basicerotini 415

Kuala Kubu Bahru (03°35'N.,101°37'E.), worker paratype (D. H. Murphy, v. 1955); West Johore:
Gunong Pulai, near Johore Bahru (0r29'N.,103°44'E.) (D. H. Murphy, 17.iii.l963); Sarawak: First
Division: Semengoh Nature Reserve, near Kuching (01°33'N.,110°20'E.), numerous worker paratypes,
2 queen paratypes, (RWT aces 68.202, 259-262, 778-80, 784, various dates between 28. v. and 20.vi.
1968); Mt Santubong, near Kuching, 1800 ft, 2 worker paratypes (G. H. L. Rothschild, 5.vi.68);
Fourtli Division: Gunong Mulu National Park (Long Patau), 3 worker paratypes (B. Bolton, 18.x. 77);
Sabah: Lungmanis, mile 45 (Labuk Rd, ex Sandakan), paratype worker (RWT ace 68.476, 12-13. vi.
1968); Sepilok Forest Reserve, near Sandakan, 7 paratype workers, 1 paratype queen (RWT ace
68.451, 12. vi. 1968); Sibuga, near Sandakan, 1 worker paratype, 1 queen paratype (RWT ace 68.378,
9.vi.l968); Umas Umas, near Tawau, 7 paratype workers, paratype queen (RWT aces 68.626, 627,
12-13. vi. 1968); Quoin Hill Research Station, near Tawau, 750 ft, 36 worker paratypes, queen paratype
(RWT aces 68.613-7, 619-621, 16-19.vi.l968). Indonesia: Sumatra: Liwa, 9 paratype workers (M. S.
Harvey, 5.ix.l984); Sulawesi: Dumoga-Bone National Park (00°33'N.,123°59'E.), c. 200 m (M. Horak,
4.iii.l985; Ranu River, 3 worker paratypes (M. Grandell, 4.iii.l985). All specimens from Berlese
funnel extractions of rainforest leaf litter or mould.

Type Deposition

Holotype and most paratypes in ANIC (type No. 7780); holotype gold-palladium coated for SEM
study. Worker paratypes in BMNH, BPBM, LACM, MHNG, MKUB, MKUC.

Worker

General features as illustrated. All Class A attributes present, with those of Class B,
unless otherwise indicated. Dimensions (mm): HL 0-66; HW 0-71; CI 108; ML 0-21;
MI 32; SL 0-42; SI 59; PW 0-44; WL 0-81. Posterior borders of mandibles oblique,
framing a narrow, roughly triangular transverse gap against the clypeus when closed.
Eyes moderately large, with 6-8 facets. Occipital border broadly, distinctly, but relatively
very shallowly emarginate; posterior occipital angles almost obliterated, broadly rounded
and very obtuse (about 120°). Petiolar node in dorsal view essentially square, its length and
breadth subequal (any bias longitudinal). One pair of specialised enlarged hairs only on
frons, each hair clavate, barely expanded, very slender, almost parallel-sided and apically
pointed. Such hairs are apparently normally lacking on promesonotum, petiolar node,
postpetiole, and dorsum of first gastral tergite; a few large hairs, as usual, at the gastral
apex. Ground pilosity almost lacking, except a few small hairs on the postpetiolar dorsum,
scapes, tibiae and tarsi, and exceedingly minute hairs in the punctures of the first gastral
tergum.

Mainland Malaysian specimens and those from the Kuching area collectively have
HW 0-66-0 -75; the 3 from Gunong Mulu 0-65-0 -70; those from Sabah 0-63-0-68, and
specimens from Sulawesi 0-63-0-66. Reduction in average size of E. omnivaga workers
from west to east thus seems evident. The series from Liwa, Sumatra, has the largest
specimens of all with HW 0-73-0-78.

Queen

General features as in the worker, with the usual differences of full alate sexuality.
Specialised posterior cephalic hairs as in worker. Additional such hairs (maximum known
complement; apart from those at the gastral apex) as follows: a single hair above each
eye [represented in 4 of 7 specimens (these from Sungei Simei Falls, Quoin Hill and
Sepilok), and thus probably easily lost]; those of pronotum, scutum and scutellum as
described above for E. jenny a (and apparently homologous); a single posterolateral pair on
postpetiole, apparently homologous with those of other species (although they are lacking
on E. omnivaga workers); gastral hairs more abundant than in the worker, less-clearly
deployed in longitudinal rows (again similar to the condition in E. jennya). The mesosomal
hairs seem to be easily shed, and most specimens have an incomplete complement.

E. omnivaga is sympatric in parts of its range in West Malaysia or Borneo with all
8 other species of Asian Eurhopalothrix described here, and with E. heliscata (Fig. 1).
It is undoubtedly also sympatric in places with E. procera, judging from the known records
of the latter (Brown & Kempf 1960, fig. 56).

416

R. W. Taylor

E. philippina Brown & Kempf
(Figs 27-29, 51)
Distribution

This species was described from near Dumaguete (09°20'N.,123°18'E.), Negros I.,
Philippines. The following record considerably extends its range: Philippines: Luzon:
Mt Makiling, c. 150 ft below summit, in htter (R. A. Morse, ii.l965) (specimens in MCZC
and ANIC).

Figs 27-29. Eurhopalothrix philippina Brown & Kempf, worker (Mt Makiling, Luzon, Philippines
(ANIC), standard views, HW 0-65 mm; PW 0-41 mm: WL 0-78 mm.

New Asian Ants of the Basicerotini

417

E. platisquama, sp. nov.
(Figs 30-33, 52)
Type Locality

W. Malaysia: Pahang/Perak: Cameron Highlands (04°30'N.,I01''34'E.).

Distribution, Material Examined

W. Malaysia: Selangor: Ulu Gombak Field Station, 3 paratype workers (B. Bolton, 7.X.73);
Pahang/Pcrak: Cameron Highlands (type locality), 3200 ft, holotype, paratype worker, valley floor,
upper dipterocarp forest (D. H. Murphy, 8.viii.l964). Indonesia: Sumatra: Liwa, 9 paratype workers
(M. S. Harvey, 5.ix.l984). All specimens from Berlese funnel or Winkler bag extractions of leaf
rainforest mould.

Figs 30-32. Eurhopalothrix platisquama, holotype worker, standard views, see description for
dimensions.

418

R. W. Taylor

Figs 33, 34. Details of specialised ground pilosity: 33, Eurhopalothrix platisquama, side of mesothorax;
34, Eurhopalothrix seguensis, side of pronotum; worker holotypes, scale line 20 n.

Type Deposition

Holotype in ANIC (type No. 7781), gold-palladium coated for SEM study. Paratypes in BMNH,
MCZC, MKUB.

Worker

General features as illustrated. All Class A attributes present, with those of Class B,
unless otherwise indicated. Dimensions (mm): HL 0-76; HW 0-85; CI 112; ML 0-19;
MI 25; SL 0-43; SI 50; PW 0-49; WL 0-86. The Cameron Highlands and U. Gombak
specimens collectively have HW 0-84-0 -85, and those from Liwa 0-82-0 -86. Eyes relatively
large, each with about 20 facets, maximum diameter approaching that of a funicular club.
Occipital border almost straight, transverse (its outhne at most minutely curved or sinuate).
Petiolar node in dorsal view essentially square, its length and breadth subequal to distinctly
but slightly wider than long.

Frons and most dorsal body surfaces, sides of pronotum and undersides of head and
gaster covered almost entirely by a ground pilosity of dense, flattened, thoroughly appressed,
squamous, shining silvery hairs, which are almost contiguous and fill or overlap the
punctures bearing them. These hairs with feathered edges under SEM examination.
Specialised hairs well differentiated from the enlarged ground pilosity. Each clavate, barely
expanded, though somewhat thick and columnar; 2 pairs only on frons, grouped postero-
medially in a tight square array (the hairs spaced by about their average length); one pair
(posterolateral) on postpetiole (missing from holotype); lacking elsewhere.

E. rothschildi, sp. no v.
(Figs 38-40, 54)
Type Locality

Malaysia: Sarawalc First Division: Mt Santubong (05°52'N.,118''55'E.), near Kuching.

Distribution, Material Examined

Known only from the unique worker holotype, from a rainforest leaf litter berlesate, at c. 1800 ft
(G. H. L. Rothschild), 5.vi.l968; RWT ace 68.294).

Type Deposition

Holotype in ANIC (type No. 7782); gold-palladium coated for SEM study.

Named for my friend and colleague George Rothschild, formerly Sarawak Government Entomologist.

New Asian Ants of the Basicerotini

419

Figs 35-37. Eurhopalothrix procera, worker [Yawasora, near Wewak (03°35'S.,143°35'E.), Papua
New Guinea], standard views, HW 01-12 mm; PW 0-69 mm; WL 1-28 mm.

420

R. W. Taylor

Worker

General features as illustrated. All Class A attributes present, with those of Class B,
unless otherwise indicated. Dimensions (mm): HL 0-54; HW 0-59; CI 110; ML 0-10;
MI 20; SL 0-32; SI 54; PW 0-35; WL 0-57. Outer mandibular borders in frontal view
more-or-less continuously (weakly) convex. Face of clypeus between frontal lobes divided
by an obtuse, very low, transversely arched ridge; anterior clypeal border relatively deeply
emarginate. Frons spanned by a slightly arched, conspicuous, obtuse transverse tumosity or
ridge between eyes (Fig. 40). Eyes small but distinct, 5-faceted. Occipital border broadly,
distinctly, but shallowly emarginate. Petiolar node in dorsal view distinctly wider than long.
One pair of specialised erect hairs on frons (one only extant in the holotype), near midline
of occipital border, and 6 in 2 longitudinal rows of 3, on dorsum of first gastral tergite;
such hairs otherwise lacking on promesonotum, petiolar node, and postpetiole. The intact
cephalic hair clavate, expanded to about \ its height; the erect gastral hairs somewhat longer.

Figs 38-40. Eurhopalothrix rothschildi, holotype worker, standard views, see description for dimensions.

New Asian Ants of the Basicerotini 421

with almost bulbous tips surmounting slender columnar stems. Ground pilosity moderately
well developed, more concentrated on frontal lobes, promesonotal dorsum and postpetiole
than elsewhere; a ragged linear band of hairs crosses the frons between the eyes, along the
transocular ridge (somewhat encrusted and obscured in the holotype).

E. seguensis, sp. nov.
(Figs 34, 41-43, 55)
Type Locality

Malaysia: Sarawak: First Division: Kampong Segu, 20 miles S.W. of Kuching (01°33'N.,110°20'E.).

Distribution, Type Deposition

Known only from the unique worker holotype, from a rainforest leaf mould berlesate (RWT ace
68.289, 4.vi.l968). In ANIC (type No. 7783); gold-palladium coated for SEM study.

Named for the type locality.

Figs 41-43. Eurhopalothrix seguensis, holotype worker, standard views, see description for dimensions.

422

R. W. Taylor

Figs 44-47. Eurhopalothrix species, dorsal views of postpetiole and gaster; postpetiole widths (mm)
are cited for scale: 44, E. browni (0-30); 45, E. chapmani (0-53); 46, E. coronata (0-30); 47, E. dubia
(0-43). The specimens are those illustrated above.

New Asian Ants of the Basicerotini

423

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Figs 48-51. Eurhopalothrix species, dorsal views of postpetiole and gaster; postpetiole widths (mm)
are cited for scale: 48, E. jennya (0-35); 49, E. heliscata (0-52); 50, E. omnivaga (0-43); E. philippina
(0-39). The specimens are those illustrated above.

424

R. W. Taylor

Worker

General features as illustrated. All Class A attributes present, with those of Class B,
unless otherwise indicated. Dimensions (mm): HL 0-71; HW 0-79; CI 112; ML 0-19;
MI 27; SL 0-41; SI 52; PW 0-48; WL 0-83. Eyes large, as in E. platisquama. Occipital
border almost straight, transverse (its outline at most minutely curved or sinuous). Posterior
occipital angles obtusely rounded, forming angles of about 130°. Mesosomal profile not a
continuous curve, its outline interrupted at the promesonotal/propodeal junction by a minute

Figs 52-55. Eurhopalothrix species, dorsal views of postpetiole and gaster; postpetiole widths (mm)
are cited for scale: 52, E. platisquama (0-47); E. procera (0-64); E. rothschildi (0-35); 55, E. seguensis
(0-44). The specimens are those illustrated above.

New Asian Ants of the Basicerotini 425

indentation; the mesometanotal suture not incised dorsally to break the surrounding
sculpture. Petiolar node in dorsal view essentially square, its length and breadth subequal
(bias transverse).

Frons and most dorsal body surfaces with ground pilosity of dense, flattened, appressed,
squamous, shining silvery hairs, which are less strongly developed than in E. pladsquama
and E. dubia, so as barely to overlap the punctures in which they lie, which remain more
clearly visible than in the other species mentioned. Four relatively short specialised hairs on
posterior occipital border, the median pair adjacent, the laterals each about midway between
them and the posterior occipital angles; the hairs clavate, barely expanded, though somewhat
thick and columnar. Erect hairs lacking elsewhere on promesonotum, petiolar node and
dorsum of first gastral tergite; one pair (posterolateral) on postpetiole.

Acknowledgments

The cooperation of Rev. B. B. Lowery SJ, Rudolf Kohout, Dr G. B. Monteith and
Barry Bolton is gratefully acknowledged. Sandy Smith drafted Fig. 1. The micrograph
plates were prepared with assistance and advice from Colin Beaton, Katherine Pickerd,
Elizabeth Brooks and Chris Hunt.

References

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Manuscript received 23 January 1989, accepted 3 August 1989