Tapinoma melanocephalum (Fabricius, 1793)

(Figure 2 (a–c))

Formica melanocephala Fabricius, 1793: 353 (w.) French Guiana. Neotropical.

Diagnosis

Worker. An easily distinguished species by its small size (1.20–1.90 mm) and bicoloured body. Head and mesosoma brown or dark brown, antennae, maxillary palps and mandibles pale brown to yellow, gaster and legs pale yellow; mesosoma without erect hairs.

Material examined

Yemen, Socotra Island, Dehejamo, 22 April 2014, 563 m, (M. R. Sharaf leg.), 12.59049°N, 54.05205°E (9 w, KSMA); Yemen, Socotra Island, Himihil Protectorate, 23 April 2014, 372 m, (M. R. Sharaf leg.), 12.57615°N, 54.30651°E (3 w, KSMA); Yemen, Socotra Island, Dixam (W. Zereg), 24 April 2014, 279 m, (M. R. Sharaf leg.), 12.46868°N, 54.01091°E (6 w, KSMA); Yemen, Socotra Island, Lehanoh, 22 April 2014, 931 m, (M. R. Sharaf leg.), 12.57583°N, 54.04836°E (2 w, KSMA, 1 w, CASC) .

Geographic range

An invasive species with a worldwide distribution (Wetterer 2009a). It was recorded from KSA and Oman (Collingwood 1985), Yemen (Collingwood and Agosti 1996), and the United Arab Emirates (UAE) (Collingwood et al. 1997).

Ecological and biological notes

The nesting and foraging habitats of this species are diverse. Several specimens were found foraging on a tree located on a mountainside with nearby stream drainage. The area had moist soils with high plant diversity, especially Adiantum capillus-veneris L. ( Pteridaceae), which was abundant. The area was dominated by the ponerine ant, Brachyponera sennaarensis (Mayr, 1862) . A nest series was collected from an area with moist soil and dense grasses. The area was rich in decayed animal faeces. Another nest was collected by sifting the leaf litter next to a stream and small pool with many scattered date palm ( Phoenix dactylifera L.) trees. Another nest series was found under the bark of a recently cut dragon blood tree, Dracaena cinnabari Balf. f. ( Asparagaceae) and associated with curculionid beetles. This invasive species has a broad range of habitat preference worldwide (Wetterer 2009a), including pre-existing cavities made of plant materials, and in larders and pantries, and nesting in walls and potted plants indoors (Ellison et al. 2012).