Tapinoma

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Tapinoma
Temporal range: 37.2–0 Ma Eocene – Recent
Tapinoma atriceps
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Dolichoderinae
Tribe: Tapinomini
Genus: Tapinoma
Foerster, 1850
Type species
Tapinoma collina (junior synonym of Tapinoma erraticum)
Diversity
96 species
6 fossil species
(Species Checklist, Species by Country)

Tapinoma atriceps casent0173743 profile 1.jpg

Tapinoma atriceps

Tapinoma atriceps casent0173743 dorsal 1.jpg

Specimen Label

Synonyms

Most Tapinoma species are arboreal and some live in close associations with myrmecophyte plants (Wheeler, 1922; Bolton, 1973a). In addition, they seem to be generalised foragers (Brown, 2000). Species of Tapinoma utilize a wide variety of nest sites, including open soil, soil covered with rocks, wood or other plant material, rotten or dead wood, plant stems, or almost any appropriately-sized preformed cavity. Nests are of moderate to large size, and may contain up to several hundred dealate queens. Tapinoma are general scavengers, but have a preference for honeydew and often tend aphids or coccids. (Shattuck 1992)

At a Glance • Haiku  

Identification

Shattuck (1992) - Worker: Mandibles with 3 to 7 teeth, about 7 denticles, and the basal angle indistinct and with a relatively uninterrupted curve between the masticatory and basal margins; petiolar scale reduced or absent; first gastral segment projecting anteriorly and concealing petiole in dorsal view; dorsal face of propodeum shorter than declivitous face; erect hairs generally lacking on pronotum. World wide Queen: Gastral compression dorsoventral; petiolar scale reduced or absent; dorsal face of propodeum shorter than declivitous face; first gastral segment projecting anteriorly and concealing petiole in dorsal view; basal angle of mandible indistinct, with a relatively uninterrupted curve between the masticatory and basal margins. Male: Scape length much longer than the length of funicular segments 1 +2+3; petiolar scale reduced, strongly inclined anteriorly; first gastral segment projecting anteriorly, sometimes concealing the petiole in dorsal view; mandible with 8 to 15 teeth and 0 to 3 denticles.

Workers can be separated from those of all other dolichoderine genera based on the lack of a petiolar node (occasionally greatly reduced), the lack of a basal mandibular angle, and the four apparent gastral tergites.

Fisher and Bolton (2007) - Within the Dolichoderinae two genera, Tapinoma and Technomyrmex, are isolated in their female castes by the synapomorphic extreme reduction of the petiole and its accommodation in a longitudinal groove or impression in the ventral surface of the first gastral tergite, which overhangs and conceals the petiole in dorsal view when the mesosoma and gaster are aligned. The petiole is so reduced in these two genera that in profile there is no trace of a node or scale; at most there is a very short raised surface immediately behind the peduncle. The function of this raised surface is to provide an insertion-site for the exterior levator muscle of the petiole.

Technomyrmex and Tapinoma are separated in the female castes by the contrasting morphologies of their gastral apices. In Technomyrmex the sclerites of the gastral apex are unspecialised, except that the pygidium is small. Gastral tergite 5 is therefore in line with tergites 1 – 4 and as a result all five tergites are visible in dorsal view. In contrast the pygidium in Tapinoma is reflexed, the fifth tergite being folded back and down, below the fourth tergite, and is clearly visible in ventral view. Also in that view the fourth tergite frequently forms a distinct projecting rim above the reflexed fifth. In consequence only gastral tergites 1 – 4 are visible in dorsal view.

Keys including this Genus

 

Keys to Species in this Genus

Distribution

Distribution and Richness based on AntMaps

Species by Region

Number of species within biogeographic regions, along with the total number of species for each region.

Afrotropical Region Australasian Region Indo-Australian Region Malagasy Region Nearctic Region Neotropical Region Oriental Region Palaearctic Region
Species 25 5 17 5 4 19 10 31
Total Species 2841 1736 3045 932 835 4379 1741 2862

Fossils

Fossils are known from: Baltic amber (Bartonian, Middle to Late Eocene), Bitterfeld amber (Bartonian, Middle to Late Eocene), Dominican amber, Dominican Republic (Burdigalian, Early Miocene), Peruvian amber, Pebas Formation, Tamshiyacu, Peru (late Middle Miocene), Rovno amber (Priabonian, Late Eocene), Shanwang, China (Early Miocene), Sicilian amber, Italy (Late/Upper Miocene), Zhangpu amber, Zhangpu County, Fujian Province, China (Miocene) (an unidentified species, Wang et al., 2021).

Biology

  • The thief ant Solenopsis fugax stealing Tapinoma brood. Thief ants rob brood from many different ants, and are able to deter them with nasty alkaloid poison, in this case 2-butyl-5-heptylpyrrolidine. Photo by Phil Honle.

Association with Other Organisms

Explore-icon.png Explore: Show all Associate data or Search these data. See also a list of all data tables or learn how data is managed.

Species Uncertain

Orthoptera

An unknown species of Tapinoma is a host for the cricket Myrmecophilus arboreus in New Guinea.

All Associate Records for Genus

Click here to show/hide associate data.
Taxon Relationship Associate Type Associate Taxon Associate Relationship Locality Source Notes
Tapinoma host cricket Myrmecophilus arboreus myrmecophile New Guinea
Tapinoma erraticum host aphelinid wasp Aphytis melinus parasite Universal Chalcidoidea Database associate
Tapinoma erraticum host encyrtid wasp Leptomastix dactylopii parasite Universal Chalcidoidea Database associate
Tapinoma erraticum host ichneumonid wasp Hybrizon buccatus parasitoid Quevillon, 2018 encounter mode primary; direct transmission; transmission outside nest
Tapinoma erraticum host phorid fly Pseudacteon formicarum parasitoid Quevillon, 2018 encounter mode primary; direct transmission; transmission outside nest
Tapinoma erraticum mutualist aphid Aphis craccivora trophobiont Mortazavi et al., 2015; Saddiqui et al., 2019
Tapinoma erraticum mutualist aphid Aphis fabae trophobiont Mortazavi et al., 2015; Saddiqui et al., 2019
Tapinoma erraticum mutualist aphid Aphis gossypii trophobiont Mortazavi et al., 2015; Saddiqui et al., 2019
Tapinoma erraticum mutualist aphid Aphis pomi trophobiont Mortazavi et al., 2015; Saddiqui et al., 2019
Tapinoma erraticum mutualist aphid Aphis salicariae trophobiont Mortazavi et al., 2015; Saddiqui et al., 2019
Tapinoma erraticum mutualist aphid Brachycaudus amygdalinus trophobiont Mortazavi et al., 2015; Saddiqui et al., 2019
Tapinoma erraticum mutualist aphid Brachycaudus tragopogonis trophobiont Mortazavi et al., 2015; Saddiqui et al., 2019
Tapinoma erraticum mutualist aphid Chaitophorus israeliticus trophobiont Mortazavi et al., 2015; Saddiqui et al., 2019
Tapinoma erraticum mutualist aphid Cinara pini trophobiont Latibari et al., 2016; Saddiqui et al., 2019
Tapinoma indicum mutualist aphid Aphis gossypii trophobiont Lokeshwari et al., 2015; Saddiqui et al., 2019
Tapinoma litorale xenobiont ant Camponotus planatus xenobiont
Tapinoma litorale xenobiont ant Cephalotes varians xenobiont
Tapinoma litorale xenobiont ant Pseudomyrmex elongatulus xenobiont
Tapinoma melanocephalum mutualist aphid Aphis eugeniae trophobiont Pakistan Gull-E-Fareen et al., 2020
Tapinoma melanocephalum mutualist aphid Aphis fabae trophobiont Pakistan Gull-E-Fareen et al., 2020
Tapinoma melanocephalum mutualist aphid Aphis fabae solanella trophobiont Pakistan Gull-E-Fareen et al., 2020
Tapinoma melanocephalum mutualist aphid Aphis gossypii trophobiont Pakistan Gull-E-Fareen et al., 2020; Idechiil et al., 2007; Lokeshwari et al., 2015; Siddiqui et al., 2019
Tapinoma melanocephalum mutualist aphid Aphis pomi trophobiont Pakistan Gull-E-Fareen et al., 2020
Tapinoma melanocephalum mutualist aphid Greenidea (Greenidea) decaspermi trophobiont Pakistan Gull-E-Fareen et al., 2020
Tapinoma melanocephalum mutualist aphid Greenidea (Greenidea) ficicola trophobiont Pakistan Gull-E-Fareen et al., 2020
Tapinoma melanocephalum mutualist aphid Greenidea (Trichosiphum) formosana trophobiont Pakistan Gull-E-Fareen et al., 2020
Tapinoma melanocephalum mutualist aphid Hysteroneura setariae trophobiont Pakistan Gull-E-Fareen et al., 2020; Idechiil et al., 2007; Siddiqui et al., 2019
Tapinoma melanocephalum mutualist aphid Macrosiphoniella sanborni trophobiont Pakistan Gull-E-Fareen et al., 2020
Tapinoma melanocephalum mutualist aphid Myzus persicae trophobiont Pakistan Gull-E-Fareen et al., 2020Siddiqui et al., 2019; Zhou et al., 2015
Tapinoma melanocephalum mutualist aphid Ovatus crataegarius trophobiont Pakistan Siddiqui et al., 2019; Gull-E-Fareen et al., 2020
Tapinoma melanocephalum mutualist aphid Pentalonia nigronervosa trophobiont Pakistan Siddiqui et al., 2019; Gull-E-Fareen et al., 2020; Idechiil et al., 2007
Tapinoma melanocephalum mutualist aphid Tinocallis kahawaluokalani trophobiont Pakistan Siddiqui et al., 2019; Gull-E-Fareen et al., 2020
Tapinoma melanocephalum mutualist aphid Tuberolachnus salignus trophobiont Pakistan Siddiqui et al., 2019; Gull-E-Fareen et al., 2020
Tapinoma melanocephalum mutualist butterfly Lampides boeticus Obregon et al. 2015
Tapinoma nigerrimum host fungus Myrmicinosporidium durum pathogen Portugal Gonçalves et al., 2012.
Tapinoma nigerrimum mutualist butterfly Lampides boeticus Obregon et al. 2015
Tapinoma nigerrimum mutualist butterfly Leptotes pirithous Obregon et al. 2015
Tapinoma nigerrimum mutualist butterfly Tomares ballus Obregon et al. 2015
Tapinoma sessile host ''Microdon'' fly Microdon globosus predator Florida, Missouri, Pennsylvania, Wisconsin Fabricius, 1805
Tapinoma sessile host cestode Mesocestoides sp. parasitoid Quevillon, 2018 encounter mode secondary; indirect transmission; transmission outside nest
Tapinoma sessile host cricket Myrmecophilus pergandei myrmecophile United States
Tapinoma sessile mutualist aphid Aphis asclepiadis trophobiont Addicott, 1979a; Jones, 1927; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Aphis gossypii trophobiont Powell and Silverman, 2010; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Aphis helianthi trophobiont Mooney et al., 2015; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Aphis lugentis trophobiont Favret et al., 2010; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Aphis salicariae trophobiont Addicott, 1979a; Mooney et al., 2015; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Aphis varians trophobiont Addicott, 1979a; Mooney et al., 2015; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Bipersona torticauda trophobiont Jones, 1927; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Brachycaudus cardui trophobiont Jones, 1927; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Chaitophorus populicola trophobiont Jones, 1927; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Chaitophorus populifolii trophobiont Jones, 1927; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Chaitophorus viminalis trophobiont Jones, 1927; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Cinara atlantica trophobiont Favret et al., 2010; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Cinara pineti trophobiont Jones, 1927; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Cinara ponderosae trophobiont Jones, 1927; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Dysaphis sorbi trophobiont Jones, 1927; Saddiqui et al., 2019
Tapinoma sessile mutualist aphid Myzus persicae trophobiont Powell and Silverman, 2010; Saddiqui et al., 2019
Tapinoma simrothi host fungus Myrmicinosporidium durum pathogen Portugal Gonçalves et al., 2012.
Tapinoma simrothi mutualist aphid Aphis craccivora trophobiont Stary, 1969; Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Aphis davletshinae trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Aphis fabae trophobiont Stary, 1969; Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Aphis frangulae trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Aphis gossypii trophobiont Stary, 1969; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Aphis nasturtii trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Aphis nerii trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Aphis pomi trophobiont Stary, 1969; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Aphis punicae trophobiont Stary, 1969; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Aphis rumicis trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Aphis umbrella trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Brachycaudus cardui trophobiont Stary, 1969; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Brachycaudus helichrysi trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Brachyonguis harmalae trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Brachyonguis tamaricophilus trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Capitophorus inulae trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Cinara cedri trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Colorado absinthiella trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Eulachnus tuberculostommata trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Hyalopterus pruni trophobiont Stary, 1969; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Myzus persicae trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Nearctaphis bakeri trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Pterochloroides persicae trophobiont Stary, 1969; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Rhopalosiphum maidis trophobiont Stary, 1969; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Rhopalosiphum padi trophobiont Shiran et al., 2013; Saddiqui et al., 2019
Tapinoma simrothi mutualist aphid Thelaxes suberis trophobiont Stary, 1969; Saddiqui et al., 2019

Flight Period

All Flight Records for Genus

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Taxon Month Source Notes
Tapinoma erraticum May Jun Jul antkeeping.info
Tapinoma glabrella May Jun Seifert et al., 2024
Tapinoma insularis Apr Seifert et al. (2024)
Tapinoma madeirense Jun Jul antkeeping.info
Tapinoma magnum Apr May Jun Jul Aug Sep Seifert et al., 2017 April-June in Italy, Germany, and the Netherlands; August-September in Algeria
Tapinoma minutum Mar antkeeping.info
Tapinoma sessile Apr May Jun Jul antkeeping.info

Life History Traits

  • Mean colony size: 100's to 2000-5000 (Greer et al., 2021)
  • Compound colony type: not parasitic (Greer et al., 2021)
  • Nest site: hypogaeic; arboreal (Greer et al., 2021)
  • Diet class: omnivore (Greer et al., 2021)
  • Foraging stratum: subterranean/leaf litter; arboreal (Greer et al., 2021)
  • Foraging behaviour: cooperative (Greer et al., 2021)

Castes

Morphology

Worker Morphology

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• Antennal segment count: 8; 11; 12 • Antennal club: absent-gradual • Palp formula: 6,4 • Total dental count: 5-20(+) • Spur formula: 1 simple-pectinate, 1 simple-pectinate • Eyes: >100 ommatidia • Scrobes: absent • Pronotal Spines: absent • Mesonotal Spines: absent • Propodeal Spines: absent • Petiolar Spines: absent • Caste: monomorphic, dimorphic in some species • Sting: absent • Metaplural Gland: present • Cocoon: absent

Karyotype

Species Uncertain

  • n = 5, 2n = 10 (Malaysia) (Goni et al., 1982).

All Karyotype Records for Genus

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Taxon Haploid Diploid Karyotype Locality Source Notes
Tapinoma 5 10 Malaysia Goni et al., 1982
Tapinoma erraticum 8 16 Switzerland Hauschteck-Jungen & Jungen, 1983
Tapinoma erraticum 8 16 12M+2SM+2ST Spain Palomeque et al., 1988; Lorite et al., 1998b
Tapinoma indicum 10 8M+2A India Imai et al., 1984
Tapinoma indicum 7 Crozier, 1975
Tapinoma melanocephalum 10 Indonesia Imai et al., 1985
Tapinoma melanocephalum 10 8M+2A India Imai et al., 1984
Tapinoma melanocephalum 5 10 USA Crozier, 1970a; Crozier, 1970b
Tapinoma nigerrimum 9 Tunisia Hauschteck-Jungen & Jungen, 1983
Tapinoma nigerrimum 9 18 10M+4SM+4ST Spain Palomeque et al., 1988; Palomeque et al., 1990a; Palomeque et al., 1990b; Palomeque et al., 1993a; Lorite et al., 1996a; Lorite et al., 1997; Lorite et al., 1998b; Lorite et al., 1999a; Lorite et al., 1999b; Lorite et al., 2002a
Tapinoma sessile 8 16 14M+2A USA Crozier, 1970a; Taber & Cokendolpher, 1988
Tapinoma simrothi 9 Crozier, 1975
Tapinoma simrothi 9 18 Spain; Tunisia Hauschteck-Jungen & Jungen, 1983

Phylogeny

Dolichoderinae
Tapinomini
Bothriomyrmecini
Dolichoderini

Dolichoderus  (150 species, 51 fossil species)

Leptomyrmecini

See Phylogeny of Dolichoderinae for details.

Nomenclature

The following information is derived from Barry Bolton's Online Catalogue of the Ants of the World.

  • TAPINOMA [Dolichoderinae: Tapinomini]
    • Tapinoma Foerster, 1850a: 43. Type-species: Tapinoma collina (junior synonym of Formica erratica), by monotypy.
    • Tapinoma senior synonym of Micromyrma: Mayr, 1863: 455; Emery, 1913a: 38; Smith, M.R. 1951a: 837; Shattuck, 1992c: 146.
    • Tapinoma senior synonym of Neoclystopsenella: Brown, 1988a: 337.
    • Tapinoma senior synonym of Semonius, Zatapinoma: Shattuck, 1992c: 146.
    • Tapinoma senior synonym of Pseudaphomomyrmex: Fisher & Bolton, 2007: 66.
  • MICROMYRMA [junior synonym of Tapinoma]
    • Micromyrma Dufour, 1857: 60. Type-species: Micromyrma pygmaea, by monotypy.
    • [Type-species not Formica erratica, unjustified subsequent designation by Wheeler, W.M. 1911f: 167.]
    • Micromyrma subgenus of Tapinoma: Santschi, 1928e: 475; Chapman & Capco, 1951: 192.
    • Micromyrma junior synonym of Tapinoma: Mayr, 1863: 455; Forel, 1878: 385; Dalla Torre, 1893: 164; Emery, 1913a: 38; Smith, M.R. 1951a: 837; Shattuck, 1992c: 146.
  • NEOCLYSTOPSENELLA [junior synonym of Tapinoma]
    • Neoclystopsenella Kurian, 1955: 133. Type-species: Neoclystopsenella luffae, by monotypy.
    • Neoclystopsenella junior synonym of Tapinoma: Brown, 1988a: 337.
  • PSEUDAPHOMOMYRMEX [junior synonym of Tapinoma]
    • Pseudaphomomyrmex Wheeler, W.M. 1920: 53. Type-species: Aphomomyrmex emeryi, by original designation.
    • Pseudaphomomyrmex junior synonym of Aphomomyrmex: Emery, 1925b: 44.
    • Pseudaphomomyrmex revived from synonymy: Chapman & Capco, 1951: 214.
    • Pseudaphomomyrmex in Dolichoderinae: LaPolla & Longino, 2006: 305.
    • Pseudaphomomyrmex junior synonym of Tapinoma: Fisher & Bolton, 2007: 66.
  • SEMONIUS [junior synonym of Tapinoma]
    • Semonius Forel, 1910f: 21. Type-species: Semonius schultzei, by monotypy.
    • Semonius junior synonym of Tapinoma: Shattuck, 1992c: 146.
  • ZATAPINOMA [junior synonym of Tapinoma]
    • Zatapinoma Wheeler, W.M. 1928a: 20. Type-species: Zatapinoma annandalei, by original designation.
    • Zatapinoma junior synonym of Tapinoma: Shattuck, 1992c: 146.

Unless otherwise noted the text for the remainder of this section is reported from the publication that includes the original description.

Description

Shattuck (1992):

Worker

HEAD. Vertex slightly convex to concave. Compound eyes present, approximately round; relatively anterior on head. Ocelli absent. Antennae 12 segmented (occasionally 11, rarely 8 segmented). Scape relatively short, at most surpassing the vertex by less than one-half (often less than one-third) its length. Anterolateral clypeal margin even with the mediolateral region. Anteromedial clypeal margin variable, either entire, without a central notch or concavity of any type; with a broad, shallow concavity; orwith a distinct, central notch separated from the general outline of the margin by distinct, angular corners. Anterior clypeal setae 2-6 (or absent); short, less than twice the maximum scape diameter or about the same length as the closed mandibles; straight or moderately curved ventrally. Posterior clypeal margin between the anterior and posterior surfaces of the antennal socket cavities. Anterior tentorial pit nearer the antennal socket than the mandibular insertion. Frontal carina present. Anterolateral hypostoma reduced to a thin sclerite. Medial hypostoma entire. Psammophore absent. MOUTHPARTS. Palp formula 6:4. Third maxillary palp segment subequal in length to segment 4. Fifth maxillary palp segment at the apical extreme of segment 4. Mandible with 3-6 (rarely 7) teeth and about 7 denticles. Apical tooth varying from subequal in length to, to slightly longer than, the subapical tooth. Basal angle indistinct, with a relatively uninterrupted curve between the two margins. Basal margin varying from denticulate distally, smooth proximally to denticulate along entire surface. MESOSOMA. Posteroventral pronotum lateral, rounded or angled. Mesopleural process absent. Anteromedial mesosternum even with the lateral regions. Declivitous and dorsal faces of propodeum convex to flat; dorsal face shorter than the declivitous face. Propodeal angle distinct (rarely with a dorsal lip or tooth) . Mesosomal spines absent (propodeum rarely with a dorsal tooth). Erect pronotal hairs absent (rarely 2 to 12); when present elongate, much longer than the maximum scape width. Dorsal pro- meso notal junction with the pronotum and mesonotum even, or with the mesonotum slightly above the pronotum. Metanotal groove either reduced to a suture (and with the mesonotum and propodeum forming a continuous, uninterrupted surface) or forming a distinct angle between the mesonotum and propodeum. Metanotal spiracle lateral and ventral of the dorsal surface when viewed in lateral profile. Propodeal spiracle lateral and ventral of the propodeal dorsum. Hind tibial spur with well developed barbules along entire inner surface (except extreme base). PETIOLE. Scale absent to reduced; when present, ridged and with a distinct angle dorsally, and strongly inclined anteriorly and with the anterior face much shorter than the posterior face. Venter with a slight to well developed lobe. GASTER. First tergite projecting anteriorly and concealing the petiole in dorsal view and with a groove or indentation for the reception of the entire height of the petiole. Anterior tergosternal suture of the first segment absent immediately lateral of the helcium and with the lateral section of the suture extending anterodorsally and terminating near the dorsal surface of the gaster. Fifth tergite ventral, gaster with 4 apparent tergites. Gastral compression dorsoventral. Fourth sternite flat across entire posterior border. GENERAL CHARACTERS. Worker caste monomorphic or rarely dimorphic. Chromosome number 5, 7, 8 or 9 (2n=1 0, Tapinoma melanocephalum, Imai et al. 1984, Imai et al. 1985b; n=5, T. melanocephalum, Crozier 1970b; n=8, Tapinoma sessile, Crozier 1970b; 2n=16, T. sessile, Taber and Cokendolpher 1988; 2n=1 0, T. indicum, Imai et a/. 1984; n=7, Tapinoma indicum, Crozier 1975; n=8, Tapinoma erraticum, Crozier 1975; n=9, Tapinoma nigerrimum, Tapinoma simrothi, Crozier 1975). Integument thin and flexible, weakly sculptured. PROVENTRICULUS. Cupola slightly broader than bulb; round; with short pile; smooth, without sculpture; and without phragma. Bulb exposed in lateral view. Longitudinal muscle No. 1 present. Occlusory tract absent.

Queen

HEAD. Vertex convex to weakly concave. Compound eyes relatively anterior on head. Antennae 11 or 12 segmented (probably also 8, see worker description). Scape short, surpassing the vertex by less than one-half scape length. Anterolateral clypeal margin even with the mediolateral region. Anteromedial clypeal margin variable, either entire (without a central notch or concavity of any type) with a broad, shallow concavity, or with a distinct, central notch separated from the general outline of the margin by distinct, angular comers. Anterior clypeal setae 4-10; short, less than twice the maximum scape diameter to about the same length as the closed mandibles; straight to moderately curved ventrally. Posterior clypeal margin posterior of the anterior posterior surfaces of the antennal socket cavities. Anterior tentorial pit nearer the antennal socket than the mandibular insertion. Anterolateral hypostoma reduced to a thin sclerite. Medial hypostoma entire. Psammophore absent. MOUTHPARTS. Palp formula 6:4. Third maxillary palp segment subequal in length to segment 4. Fifth maxillary palp segment at the apical extreme of segment 4. Mandible with 4-9 teeth and 0-12 denticles. Apical tooth slightly longer than the subapical tooth. Basal angle indistinct, with a relatively uninterrupted curve between the two margins and without a distinct tooth or angle. Basal margin varying from denticulate distally, smooth proximally to denticulate along entire surface. MESOSOMA. Posteroventral pronotum lateral, rounded or angled. Episternal suture complete. Mesopleural process absent. Anteromedial mesosternum even with the lateral regions. Axilla parallel or absent dorsally (when present, entire). Anterior axillar suture when present straight. Declivitous and dorsal faces of propodeum convex; dorsal face shorter than the declivitous face. Propodeal angle distinct. Propodeal suture absent. Mesosomal spines and tooth absent. Erect mesoscutal hairs 0- 20; when present short, less than twice the maximum scape diameter. Propodeal spiracle lateral and ventral ofthe propodeal dorsum. Hind tibial spur with well developed barbules along entire inner surface (except extreme base). WINGS. Radial cell closed. Fore wing with 1-2 cubital and 0-1 discoidal cells. Hind wing with 1-2 cells. PETIOLE. Scale reduced or absent; when present, ridged and with a distinct angle dorsally; strongly inclined anteriorly and with the anterior face much shorter than the posterior face. Venter with a slight to well developed lobe. GASTER. First segment projecting anteriorly and concealing the petiole in dorsal view and with a groove or indentation for the reception ofthe entire height ofthe petiole. Fifth tergite ventral, gaster with 4 apparent tergites. Gastral compression dorsoventral. Fourth sternite flat across entire posterior border.

Male

HEAD. Inner margin of eye entire, flat. Antennae 13 segmented (probably also with fewer segments, see worker description). Scape length much ionger than the length of funicular segments 1 +2+3 and exceeding the vertex. First funicular segment cylindrical or cone-shaped. Second funicular segment cylindrical, straight. Funicular segments 2 and 3 at most twice as long as broad. Third and fourth funicular segments straight. Anteromedial clypeal margin variable, either entire (without a central notch or concavity of any type) or with a distinct, central notch separated from the general outline of the margin by distinct, angular corners. Anterior clypeal setae 4; varying from short (about as long as the maximum diameter of the scape) to about the same length as the closed mandibles; straight. Posterior clypeal margin between the anterior and posterior surfaces of the antennal socket cavities. Anterior tentorial pit nearer the antennal socket than the mandibular insertion. Anterolateral hypostoma reduced to a thin sclerite. Medial hypostoma entire. MOUTHPARTS. Palp formula 6:4. Third maxillary palp segment subequal in length to segment 4. Fifth maxillary palp at the apical extreme of segment 4. Mandible with about 8- 15 teeth and 0-3 denticles. Apical tooth slightly longer than the subapical tooth. Basal angle indistinct, with a relatively uninterrupted curve between the two margins and without a distinct tooth or angle. Basal margin smooth and without teeth or denticles. MESOSOMA. Posteroventral pronotum lateral, rounded or angled. Episternal suture present, complete. Anteromedial mesosternum even with the lateral regions. Axilla parallel or constricted medially, and entire. Anterior axillar suture straight. Declivitous and dorsal faces of propodeum convex; dorsal face shorter than the declivitous face. Propodeal angle indistinct. WI NGS. Radial cell closed. Fore wing with 1 cubital and 0-1 discoidal cells. Pterostigmal appendage absent. Hind wing with 0, 1 or 2 cells. PETIOLE. Scale reduced; ridged and with a distinct angle dorsally; strongly inclined anteriorly and with the anterior face much shorter than the posterior face. Venter with a slight to weakly developed lobe. Attachment to gaster narrow. GASTER. First segment projecting anteriorly and sometimes concealing the petiole in dorsal view, and with a groove or indentation for the reception of the entire height of the petiole. GENITALIA. Pygostyles present. Posterior margin of subgenital plate concave. Paramere divided by a membranous region (but only weakly in some species). Digitus with a down-turned tip. Cuspis absent. Ventral lobe of volsella present as concave lobe. Aedeagus with ventral teeth.

Larva

Shape dolichoderoid. Protuberances present as a single boss on posterior of body. Body hairs sparse; simple; short. 9 spiracular pairs. Antennae short.

References