Bothroponera wasmannii

Bothroponera wasmannii is an endemic, widespread species of the Malagasy region. Across its distribution range, B. wasmannii dominates the Bothroponera in dry forest habitats where it is sympatric only with Bothroponera vazimba. In its remaining distribution range, other species within the genus co-occur with B. wasmannii, and Bothroponera cambouei, which is widely distributed throughout the humid forests, becomes the dominant species. Bothroponera wasmannii nests mainly in rotten logs; however, it can also be found on rotten sticks and branches on the ground, in soil layers, under rocks, beneath litter moss on rocks, and under rotten logs. It typically forages on the forest floor and through leaf litter, and very rarely on low-growing vegetation. Workers of this species usually fake death (thanatosis) after a nest disturbance. (Rakotonirina & Fisher, 2013)

Identification
Rakotonirina & Fisher (2013) - Worker. With head in full-face view, antennal scape not surpassing the posterior cephalic margin; dorsum of head and mesosoma not finely striate; basal half of antennal scape rounded; dorsum of mesosoma and petiole node with short and thin erect hairs; junction of propodeal dorsum and declivitous surface at a distinct angle; mesopleural suture distinct; antennal segments 6, 7, and 8 nearly as wide as long; with petiole in dorsal view, the posterior margin straight or with weak median notch; anterior half of fourth abdominal tergite (gastral tergite 2) covered with numerous and very dense small punctures between larger ones, mesosoma and petiole node with moderate such sculpture; outer surface of hind tibia usually with erect hairs; integument matte.

Apparently there are two forms found within this species. These are geographically isolated due to the presence of high mountain chains in northwestern Madagascar. The first form, in which gastral tergite 2 is densely, finely punctate between larger punctures and has a matte integument, occupies the west and southwest regions of Madagascar. In contrast, the second form is characterized by worker specimens that have a shining integument, and gastral tergite 2 is covered with nearly effaced, closely spaced, small punctures between larger, shallow punctures. This form has been collected in the northwest and northeast of the island. However, workers with intermediate degrees of these phenotypic variations also occur.

Although B. wasmannii is very similar to Bothroponera vazimba, it can be distinguished readily by its larger size, with a distinct and complete mesopleural suture, antennal segments 6, 7, and 8 nearly as wide as long, and more erect hairs on the dorsum of mesosoma and petiole node.

Key to Malagasy Bothroponera wasmannii group workers

Distribution
It occurs generally in western Madagascar and in Anjouan of the Comoros Islands. It is present on Anjouan Island in the Comoros but not Mayotte Island, although the latter is geographically closer to Madagascar. Most frequently this species has been collected from the dry forests and woodland habitats in the west of Madagascar. However, it is known also from subhumid gallery forests in the western slopes, littoral, transitional, and humid forests in the north and southeast of the island, and from disjunct montane rainforests on the high plateau. This species is also capable of colonizing human-modified habitats. There are two morphological forms; the first occurs in the dry and gallery forest habitats in the west of Madagascar, whereas the second is generally known from the transitional mesic forests and some of the rainforest sites in the north and northeast of the island. (Rakotonirina & Fisher, 2013)

Distribution based on Regional Taxon Lists
Afrotropical Region: Comoros. Malagasy Region: Madagascar.

Male
Additional specimen images of this species can be found here

Nomenclature

 *  wasmannii. Bothroponera wasmannii Forel, 1887: 383 (w.) MADAGASCAR. Forel, 1897c: 196 (q.m.). Combination in Pachycondyla (Bothroponera): Emery, 1901a: 45; in Bothroponera: Joma & Mackay, 2013: 2; Schmidt & Shattuck, 2014: 77. See also: Rakotonirina & Fisher, 2013a: 132.

Description
Rakotonirina & Fisher (2013)

Worker
(n=12): HL: 1.96–2.37, HW: 1.72–2.21, CI: 87–94, SL: 1.32–1.78, SI: 76–83, PW: 1.28–1.79, WL: 2.50–3.36, NL: 0.94–1.20, NW: 1.07–1.48, NH: 1.27–1.64, DNI: 105–132, LNI: 124–159.

In full-face view, head broadest behind level of eyes, the sides slightly convex throughout their length; the posterior margin feebly concave; eyes quite large, maximum diameter nearly equal to greatest width of antennal scape. Scape subcylindrical, relatively short, not surpassing posterior cephalic margin; segments 6, 7, and 8 almost as long as broad. Anteromedian margin of clypeus truncate and either straight or very weakly emarginated medially. Mandibles triangular, masticatory margins armed with seven to eight teeth and denticles. In profile, dorsal outline of mesosoma without uninterrupted convexity; propodeal dorsum meeting declivitous surface in a distinct angle; mesopleural sulcus distinct and complete. Hind legs with rounded basitarsus. Petiole nodiform and thick, with anterior and posterior margins that in dorsal view are respectively broadly convex and straight with weak median notch. Head finely reticulate-punctate to finely ruguloreticulate, interspersed with large punctures behind level of eyes.

Mandibles striate, with sparse punctures from which hairs arise. Dorsum of mesosoma, petiole node, and first gastral tergite covered with large punctures, the spaces between which are reticulate-punctate. Lateral portion of pronotum, mesopleuron, and lower half of propodeum generally finely reticulate-rugulose or with dense, fine rugulation. Second gastral tergite particularly with very dense, piligerous, small pits between large punctures. Standing erect hairs present on dorsum of the body, with very abundant pubescence; outer surface of hind tibiae covered with erect hairs. Dark brown to black in color with usually lighter appendages. Most specimens fairly matte except those collected from rainforest habitats.

Queen
(n=7): HL: 2.20–2.39, HW: 2.08–2.24, CI: 92–95, SL: 1.62–1.82, SI: 77–84, EL: 0.39–0.41, OI: 17–19, PW: 1.63–1.87, WL: 3.31–3.71, NL: 0.99–1.16, NW: 1.34–1.48, NH: 1.31–1.51, DNI: 127–148, LNI: 125–136. Winged queens are very similar to workers, but have a body modified with the general characteristics of the queen caste. Winged queen has a much broader head. Ergatoid queens also present in B. wasmannii, which look comparable to worker caste but have one ocellus and reduced thoracic sclerites.

Type Material
Lectotype worker, present designation, Madagascar, Antsiranana, Nosy Be (C. Keller) AntWeb specimen code CASENT0101039 [examined]. Paralectotype workers, with the same data but coded as CASENT0101040, CASENT0101041 (MHNG) [examined].