Tapinoma Foerster 1805
Creators: name: Yoshimura, Masashi
name: Fisher, Brian L.
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Formicidae
Tapinoma

description: Tapinoma Foerster 1805
(Figs 4, 9, 14, 23, 27, 29, 37, 44, 47, 53, 59, 60, 65, 70, 75, 80)
With characters of Dolichoderinae. All known males alate. Medial hypostoma present (Fig. 65). Mandible triangular, but its basal angle indistinct. Basal margin of mandible partially covered with serrate denticles and with smooth margin on its basal portion (Fig. 75). Masticatory margin of mandible wholly covered with serrate denticles. Apical tooth on masticatory margin longer than subapical one. Palpal formula 6,4 or 6,3 (one specimen each of seven species and morphospecies dissected: Fig. 80: Table 3). Length of third maxillary palpal segment varies from shorter to longer than fourth. Distal margin of labrum deeply concave and bilobed, longest setae located near apices of lobes (Fig. 70). Scape excluding basal condyle longer than flagellar segments 1+2 (Fig. 4). Pedicel conical. First and second flagellar segments straight. Axillae medially compressed, anterior and posterior margins not parallel. Petiolar node strongly inclined anteriorly, its anterior margin much shorter than posterior margin in lateral view. Node not much expanded laterally in most cases. Petiole narrowly attached to abdominal segment III. Anterior surface of abdominal segment III with indentation that fits posterior surface of petiolar node. Pygostyles present.
Distal portion of abdominal sternum IX bilobed, its distal margin widely or narrowly concave (Fig. 27). Apicoventral portion of basimere with projection (Fig. 29). Harpago moderate in size, separated from basimere by membranous region or a suture, and narrow in ventral view without ventral face (Fig. 23). Basal portion of aedeagus without distinct ventral lobe (Fig. 44). Ventral margin of aedeagus with denticles.
Forewing not extremely elongated apical to wing stigma, radial sector reaches costal margin (Fig. 53), media absent between Rs+M and 2rs-m, and 1m-cu absent in most cases. On hindwing, M+Cu present, 1rs-m+M, free sections of radial sector and cubitus, and cu-a present or absent (Figs 59, 60).
Remarks. Males of seven species (some of them morphospecies) were examined. Males of Tapinoma are distinguished easily from those of the four other Malagasy genera by an antennal scape which is longer than flagellomeres 1+2, and basal margin of the mandible partially covered with serrate denticles with a smooth basal portion (Fig. 75). In addition to these unique characters, an anteriorly inclined petiolar node is found only in Tapinoma and Technomyrmex and an apicoventral process of the basimere is found only in Tapinoma (Fig. 29) and Aptinoma (Fig. 30).
The following is a summary of the characters in Table 3 that distinguish between Tapinoma and Technomyrmex: basal margin of the mandible (character 4), apical portion of the labrum (character 7), relative length of the antennal scape (character 8), a process on the basimere (character 19), shape of the harpago (character 20), media on the forewing (character 23), and M+Cu on the hindwing (character 23). These differences hold up even though Technomyrmex is listed as having multiple states for the labrum (characters 7), and Tapinoma with a polymorphism for the scape (character 8). The ambiguity in Technomyrmex is due to an inability to dissect a paratype of Technomyrmex curiosus. Though Tapinoma is polymorphic in scape length, it never overlaps with the status observed in Technomyrmex.
A reduction of wing venation is observed in two species: T. subtile (Fig. 60) and T. mg07. The hindwings of both species are much narrower than the other males of Tapinoma in the Malagasy region, and 1rs-m+M, free sections of radial sector and cubitus, and also cu-a are weak or absent. In all other species in the Malagasy region, these veins are distinct (as in Fig. 59).
Several of the present results for Tapinoma disagree with those in previous studies. A median notch on the anterior margin of the median hypostoma is found in all male Tapinoma (Fig. 65) save T. subtile, while the margin in Shattuck (1992a) is regarded as entire. The inner margin of the eye in full-face view is concave in several species, while in Shattuck (1992a) the margin is regarded as flat. Palpal formula is 6,3 in a small species, Tapinoma subtile (Fig. 80), while the formula of Tapinoma in Shattuck (1992a, 1995) and Brandão et al. (1999) is regarded as 6,4. Relative length of the third maxillary palpal segment compared with the fourth varies from shorter than to longer than the third (See Table 4). Basal margin of the mandible is partially covered with serrate denticles with a smooth portion on its base (Fig. 75), while the margin in Shattuck (1992a, 1995) and Brandão et al. (1999) is recorded as wholly smooth. The length of the antennal scape is longer than that of flagellomeres 1+ 2 in all males of Tapinoma examined, but in some the scapes do not reach the posterior margin of the head in full-face view (as in Fig. 4); by contrast, both Shattuck (1992a, 1995) and Brandão et al. (1999) regarded the scape in Tapinoma as exceeding the posterior margin of the head. The relative length of the first flagellomere compared with its width varies from less than 1.5 times to more than three times (See Table 4), while the length in Shattuck (1992a) is regarded as less than two times. Posterior margin of the mesoscutum is notched medially in one species (T. mg10), while the character of the margin in Shattuck (1992a, 1995) and Brandão et al. (1999) is regarded as entire. A laterally expanded petiole can be seen in a male Tapinoma (T. mg11), although its dorsum is blunter than that in Ochetellus. Abdominal segment III does not always cover the petiole completely by overhanging anteriorly and seems to be nearly vertical in one male (T. mg11), although the segment of Tapinoma in Shattuck (1995) and Brandão et al. (1999) is regarded as overhanging the petiole, so that the petiole is invisible in dorsal view. The harpago is not separated from the basimere by a membranous region in two species of Tapinoma (T. mg02 and T. mg11) in the Malagasy region (Fig. 29), while this character of Tapinoma in Shattuck (1992a, 1995) and Brandão et al. (1999) is regarded as divided into two parts separated by a membranous region. The cuspis on the volsella can be found in four (T. melanocephalum, T. mg04, T. mg10, and T. mg11 as in Fig. 47) out of seven Malagasy species, while this character is regarded as absent in Tapinoma by Shattuck (1992a, 1995).
Additional discussion of characters is included in the remarks for Ochetellus.
description: Published as part of Yoshimura, Masashi & Fisher, Brian L., 2011, A revision of male ants of the Malagasy region (Hymenoptera: Formicidae): Key to genera of the subfamily Dolichoderinae, pp. 1-34 in Zootaxa 2794 on pages 13-14, DOI: 10.5281/zenodo.276993