Carebara diversa

Known for their impressive foraging trails and extreme size differences among workers. Despite a conspicuous presence over a large part of SE Asia, little is known about their biology. They are identified only as a species-complex in many field studies

Distribution based on Regional Taxon Lists
Afrotropical Region: Guinea. Indo-Australian Region: Borneo, Indonesia, Malaysia, Philippines. Oriental Region: Bangladesh, Cambodia, India, Laos, Myanmar, Thailand, Vietnam. Palaearctic Region: China, Japan.

Biology
Perhaps the best known member of what was formerly known as Pheidologeton, this species is commonly found in open and disturbed habitats, e.g. gardens, forest fringes, and are rarer in deep forests. They exhibit group-hunting behaviour, where masses of workers form long and dense trails, in an uninterrupted foraging effort (Moffett, 1988). These trails, also known as trunk trails, can last for days and are possible because of huge colonies, consisting of several hundreds of thousands of workers. This elaborate foraging behaviour has coined them the name, marauder ants.

Castes
An outstanding feature is extreme polymorphism closely coupled with polyethism (Moffett, 1987). Soldiers can be many times bigger than workers, and several small workers can ride on the back of soldiers. In C. diversa, small workers make up the bulk of foraging parties, while scattered soldiers often carry large objects, food items, or lift debris off the trunk trails.


 * Soldier

Nomenclature

 *  diversus. Oecodoma diversa Jerdon, 1851: 109 (s.w.) INDIA. Emery, 1893e: 212 (q.m.); Wheeler, G.C. & Wheeler, J. 1954a: 135 (l.); Imai, Baroni Urbani, et al. 1984: 7 (k.). Combination in Pheidole: Smith, F. 1858b: 174; in Pheidologeton: Roger, 1863b: 30; in Carebara: Fischer, Azorsa & Fisher, 2014: 71. Senior synonym of megacephala, ocellifera, pabulator: Emery, 1893e: 206; of megacephalotes: Dalla Torre, 1893: 73; of militaris, polita: Donisthorpe, 1932c: 458, 463, respectively. Current subspecies: nominal plus draco, fictus, laotinus, macgregori, philippinus, standfussi, taprobanae, tenuirugosus, williamsi. See also: Bingham, 1903: 163; Wheeler, W.M. 1919e: 85; Moffett, 1984: 7.
 * ocellifera. Pheidole ocellifera Smith, F. 1858b: 174 (w.) MYANMAR. Combination in Pheidologeton: Mayr, 1862: 750. Junior synonym of diversus: Emery, 1893e: 206.
 * megacephala. Pheidole megacephala Smith, F. 1860b: 112 (w.) INDONESIA (Batjan I.). Combination in Pheidologeton: Roger, 1863b: 30. Senior synonym of megacephalotes Dalla Torre, below. Junior synonym of diversus: Emery, 1893e: 206.
 * militaris. Pheidole militaris Smith, F. 1860a: 74 (s.w.) INDONESIA (Sulawesi). Junior synonym of diversus: Donisthorpe, 1932c: 458.
 * pabulator. Pheidole pabulator Smith, F. 1860b: 112 (s.w.) INDONESIA (Batjan I.). Combination in Pheidologeton: Mayr, 1886b: 362. Junior synonym of diversus: Emery, 1893e: 206.
 * polita. Myrmica polita Smith, F. 1860b: 108 (w.) INDONESIA (Batjan I.). Junior synonym of diversus: Donisthorpe, 1932c: 463.
 * megacephalotes. Pheidole megacephalotes Dalla Torre, 1892: 90. [Unnecessary replacement name for megacephala Smith, above.] Junior synonym of megacephala: Dalla Torre, 1893: 73.

Myrmica polita

Two worker syntypes in. Labelled “Bac.” (= Batjan I.).

Pheidole militaris

One syntype worker major and one syntype worker minor in. Labelled “Mak.”

Pheidole pabulator

Two syntypes worker major and two syntype worker minor (on a single card) in. Labelled “Bac. 2.”