Dolichoderus feae

Biological and ethological data are only available of the population from Northern Thailand. These ants nest in soil cavities, obviously deep in the ground. In contrast to all other known herdsmen Dolichoderus they are predominantly nocturnal. (Dill 2002)

Identification
Dill (2002) - A member of the Dolichoderus cuspidatus species group. Well defined by the shape of the alitrunk (± distinct “shoulders” of the pronotum, comparatively flat mesonotum, and steep propodeum with broad and ± sharp-edged and slightly overhanging transition between ascending and declivitous face) in connection with the general absence of a coarser sculpturing of the head (particularly at the sides). Especially, these characters allows an easy and clear distinction of feae from the sympatric Dolichoderus erectilobus and the geographical neighbours, Dolichoderus laotius, Dolichoderus tuberifer, and Dolichoderus cuspidatus. Strangely, the species that comes morphologically closest to feae is Dolichoderus modiglianii, only known from the Mentawei Islands off Sumatra's West Coast. The latter species differs from feae mainly in the sculpturing (moderate to distinct areolate-rugose sculpturing of the sides of the head; mesopleuron areolate-rugose instead of lengthy, ± parallel wrinkles like in feae), and in the more strongly overhanging propodeum. However, some feae populations from Southern Thailand show ± clinal transitions regarding the head sculpturing (see discussion of modiglianii).

D. feae is considerably variable in respect to size, colour, occurrence of a median superoccipital pit, and the depression of the posterior edge of the propodeum.

Distribution
Dill (2002) - From the Eastern Himalayas (Northeast India: Sikkim [also additional reports by Datta et al. 1983] and Manipur [Manmohini Devi et al. 1987]), through Myanmar and Northern Thailand, and further along the mountain range of Tenasserim to the Isthmus of Kra.

Distribution based on Regional Taxon Lists
Oriental Region: India, Myanmar, Thailand. Palaearctic Region: China.

Habitat
Dill (2002) - D. feae seems to be restricted to the evergreen mountain forests (above about 1,000 m a.s.l.) and occurs only occasionally in lower altitudes which are mostly covered by deciduous monsoon forest.

Nomenclature

 *  feae. Dolichoderus feae Emery, 1889b: 509, pl. 11, fig. 21 (w.) MYANMAR. Combination in D. (Hypoclinea): Emery, 1894c: 229. Senior synonym of caligatus, fuscus: Dill, 2002: 41.
 * fuscus. Dolichoderus feae r. fusca Emery, 1889b: 509 (w.) MYANMAR. Subspecies of feae: Emery, 1913a: 14. Raised to species: Dalla Torre, 1893: 159; Bingham, 1903: 294; Wu & Wang, 1995: 121. Junior synonym of feae: Dill, 2002: 41.
 * caligatus. Dolichoderus (Hypoclinea) feae var. caligatus Wheeler, W.M. 1927h: 99 (w.) THAILAND. Junior synonym of feae: Dill, 2002: 41.

Worker
Dill (2002) - Lectotype in brackets: HL 1.24-1.57 [1.45]; HW 1.08-1.49 [1.29]; EL 0.31-0.37 [0.33]; SL 1.22-1.47 [1.41]; AL 1.69-2.25 [2.03]; PnW 0.69-1.00 [0.88]; ML 0.41-0.65 [0.65]; MW 0.31-0.49 [0.43]; PpL 0.69-1.00 [0.94]; PpW 0.49-0.78 [0.62]; PpH 0.53-0.69; PpSW 0.37-0.51 [0.51]; PtL 0.53-0.63; PtW 0.37-0.49 [0.45]; TL 4.88-6.79 [5.94]. Indices: CI 86-95 [89]; OI 24-29 [26]; SI 99-114 [109]; MI 117-169 [150]; PpSPpl 62-86 [83]; (n = 30).

Head: From reddish-brown to dark-brown or black. Densely and finely reticulate-punctate (= micro-imbricate; figs. III-60a-b); occasionally with somewhat coarser wrinkles around the eyes; rarely (e. g. material from Southern Thailand) with additional reticulate, subareolate wrinkles, that are restricted to the area between eyes and occipital margin. Entire head bearing a yellow to silver pubescence; no erect hairs. Head mostly slightly longer than wide; suboval; occipital margin slightly concavely emarginate; often with ± narrow, pinprick-like median superoccipital pit; often with an additional, pinprick- or slit-like impression at the median vertex (position of anterior ocellus).

Alitrunk: Coloration very variable, yellow-, red-, dark-brown or black. Entire alitrunk irregularly punctate or finely reticulate (= micro-imbricate); micro-sculpturing often superimposed by somewhat coarser wrinkles, which are either ± parallel (e. g. on mesopleuron, fig. III-60c) or irregularly areolate-rugose (e. g. dorsal face of propodeum or mesonotum). Light-grey pubescent; only ventral face and coxae with scarce erect hairs. “Shoulder”-corners of pronotum rounded yet ± distinct; dorsal face of pronotum even or slightly concave, with distinct lateral edges. Mesonotum, in profile, forming a very low, hardly ascending, flattened hump, mostly with a broad median and longitudinal impression between ± distinct lateral edges; posterior delimitation of mesonotum often indistinct. Propodeum, compared to mesonotum, strongly ascending; transition between ascending dorsal and declivitous face forming a distinct, ± angular edge that is medially impressed; declivitous face, in profile, initially curved slightly forward under the edge (i. e. posterior margin of dorsal face slightly overhangs the declivitous face), than bends down and backward (fig. III-8b); the lateral corners of the edge usually somewhat expanded; declivitous face ± smooth and shiny.

Petiole: Apical margin of scale usually entire, not emarginate; reticulate-punctate (= micro- imbricate) and pubescent.

Gaster: Finely reticulate (= micro-imbricate), with dense, fine, light-grey pubescence, which forms cowlicks and, particularly on 2nd and 3rd tergite, merges in a median line; thus, depending on the incidence of light, causing the impress ion of a striation of the gaster; erect hairs scarce and restricted to the ventral face and the tip.

Type Material
Dill (2002) - Syntype workers, Tenasserim, Mt. Mooleyit, 1,000-1,900 m (Fea) [examined]; Tenasserim, Plapoo (Fea)  [examined]; Carin, Asciuii Cheba, 1,200-1,900 m (Fea) (MCZC) [examined]; Tenasserim: Kawkareet [not examined]; Tenasserim: mountains between the rivers Meekalan and Kyeat [not examined]. One syntype here designated as Lectotype (MCSN).