Pheidole megacephala (Fabricius)

MAJOR MINOR  Type location not known (Formica megacephala, Fabricius, 1793: 361, major) [note Wheeler, 1922, has the type locality as Mauritius = "Isle de France", as per the specimen label, see photomontage on the linked majors page (see below); but Forel, 1891: 176, reckoned the location was Madagascar; the area around Paris, however, was and is known as the "Isle de France" and it seems possible that "Museé" specimens in the Bosc. collection were found in a hot house in France]
Subspecies (Bolton,1995)
duplex (Pheidole megacephala F. v. duplex n. var., Santschi, 1937d: 218, major, minor & queen) from Angola - see http://www.antweb.org/specimenImages.do?code=casent0906513 appear identical to the fresh specimens I have (linked pages)
junior synonyms
perniciosa (Oecophthora perniciosa, n. sp., Gerstäcker, 1859: 263, minor; junior synonym of megacephala, Emery, 1915j: 235) from Mozambique - see (headless) http://www.antweb.org/specimenImages.do?code=casent0906517
laevigata (Myrmica (?) laevigata sp. nov., F Smith, 1855b: 130, illustrated, minor; junior synonym of pusilla, Roger, 1859: 259, of pallidula, F Smith, 1858a: 282; of megacephala, Roger, 1863b: 30; of pusilla, Emery, 1915j: 235) from Great Britain, collected at Battersea [also name used by Mayr, 1862: 747, minor, for specimen from Brazil]
speculifrons (Pheidole megacephala F. v. speculifrons n. v., Stitz, 1911b: 386, major & minor) from Tanzania, Bukoba - on linked pages (see below)
suspiciosa (Myrmica suspiciosa, F. Smith, 1859a: 148, minor; junior synonym of megacephala, Donisthorpe, 1932c: 455) from Indonesia, Aru - see http://www.antweb.org/specimenImages.do?code=casent0901409.
testacea (Atta testacea, F Smith, 1858b: 168, major & minor; junior synonym of megacephala, Brown, 1981: 530) from Brazil .

Note: Fischer & Fischer (2013) designated a "neotype"; I feel that was unnecessary given that good specimens of the junior synonyms exist, e.g. duplex.
[Fischer, G.; Fisher, B. L. 2013. A revision of Pheidole Westwood (Hymenoptera: Formicidae) in the islands of the Southwest Indian Ocean and designation of a neotype for the invasive Pheidole megacephala. Zootaxa 3683:301-356.]

Fabricius's (1793) description is at . Gerstäcker's (1859) description of perniciosa (worker) is at . F Smith's (1855b) description of laevigata (worker) is at . F Smith's (1859a) description of suspiciosa (worker) is at ; note his comment on laevigata that appears to contradict his own explicit remark only a short time before (F Smith 1858a, see below). F Smith's (1860b: 112) description of megacephala, major & minor workers, from Bachian, Celebes, is very weird and obviously not the type form, this is at ; Mayr's (1861) description (all forms, with a key to separate megacephala and pusilla) is at . Forel's (1891b) description is at . and . Forel's (1907g) description of ilgi is at . Emery (1915j) sought to clarify the megacephala-group of species, with and illustrations - see . Emery (1919a) gave further notes and corrected illustrations - see . Arnold's (1920a) translation of ilgi (as ilgii) is at . Santschi's (1937d) description of duplex is at .

Notes - changes from the Bolton (1995: 325) listing by BT, see http://antsofafrica.org/ant_species_2012/pheidole/pheidole_megacephala/pheidole_megacephala.htm for the non-Egyptian species pages:

• costauriensis - Bolton (1995: 320) had Pheidole rotundata st. costauriensis as "Subspecies of megacephala: current status". Santschi's (1914a, 1915c) descriptions of Pheidole rotundata stirps costauriensis, coupled with Emery's (1915c) drawing of melancholica and my own drawings of "Pheidole crassinoda" have led me to elevate Pheidole costauriensis to species.
• edax - the junior synonym edax (Formica edax, Forskål, 1775: 84, worker) from Egypt. Wide surveys of Egypt have never definitely found P. megacephala and from the original description this is more likely to be a variety of Pheidole fervens.
• janus - from the illustration it has to be said that janus (Pheidole janus, F Smith 1858b: 175, illustrated , soldier & minor) from Sri Lanka, is not a megacephala variety nor would it be P. teneriffana; it seems Wheeler (1922: 812) was responsible for the errors in synonymy. Pheidole janus may well merit revived species status but is extralimital to this website. F Smith's (1858b) description of janus is at .
• laevigata (Myrmica laevigata, F Smith, 1855b: 130, illustrated, worker; junior synonym of pusilla, Roger, 1859: 259, of pallidula, F Smith, 1858a: 282; of megacephala, Roger, 1863b: 30; of pusilla, Emery, 1915j: 235) from Great Britain [also name used by Mayr, 1862: 747, major, for specimen from Brazil, as Pheidole laevigata n. sp]. F Smith's (1858a) note confused the situation, as he stated, Myrmica laevigata F. Smith (1855b) was a junior synonym of Myrmica pallidula, i.e Pheidole pallidula. His descriptions of the major and sexuals clearly are ofpallidula. The explanation for the confusion surely is that Smith only had minors of laevigata, a situation that re-occurred a little later (F Smith 1859a) when he felt the minor of suspiciosa and laevigata wer similar. F Smith's (1855b) description of laevigata (worker) is at and his (1858a) note is at .
• melancholica - I also regard Pheidole melancholica (Santschi, 1912b), from Ivory Coast, as a distinct species in the crassinoda-group.
• nkomoana - Forel (1916) felt Ph. megacephala new strips nkomoana could well be a separate species. With my own description and drawings of "Pheidole species E", I have raised Pheidole nkomoana to species status.
• pusilla - on examination of the description and illustration of pusilla (Oecophthora pusilla, Heer, 1852: 15, illustrated, all forms; also illustrated by Emery, 1919a) from Madeira (with junior synonyms janus, F Smith, 1858b: 175, illustrated, major & minor workers) from Sri Lanka are clearly not megacephala; pusilla appears to be a separate species, Pheidole pusilla. Mayr (1861) separated major, minor and queens from megacephala; Mayr (1870: 981, footnote) noted that his Pheidole laevigata (Mayr, 1869, on "page 99", i.e. the 99th page of the text, actually numbered p. 747).
• talpa - I agree with Dalla Torre (1893: 95) and Emery (1915j: 235) that Pheidole talpa (Gerstäcker, 1871: 356, major; Santschi, 1930b: 67, worker & queen) is a junior synonym of Pheidole punctulata and not of megacephala as thought by Santschi (1925h: 160) and listed in Bolton (1995: 331) - note specially the rhomboid pronotum with acute angles, characteristic of punctulata.
• trinodis - from the original description by Losana (1834), it seems obvious that trinodis (Myrmica trinodis, Losana, 1834: 327, illustrated, worker; synonymy Roger, 1863: 30) from Italy, see , is not a junior synonym of megacephala and is not even a Pheidole - Losana emphasises the presence of four spines on the propodeum, i.e. possibly it was a Tetramorium. The confusion by Roger (1863b: 30, followed in Bolton, 1995) probably was caused by Losana's immediately following description of specimens of Myrmica megacephala Latr.- "the megacephala of Latreille" - ; as Losana wrote of the ant as nesting in our garden, in Piemonte (Piedmont), in northwest Italy, he almost certainly was reporting on Pheidole pallidula; note his description of a lion-coloured ant. In fact, the latter was the opinion of Emery & Forel (1879: 463).

Note: There are no confirmable reports from Egypt.

Collingwood (1985), describing specimens he recorded from Saudi Arabia, included the illustration right of the pedicel dorsum and base of the funiculus. He noted promesonotal outline evenly curved without a distinct mesonotal prominence and funicular segments 2, 3 & 4 not longer than broad.

With the availability of specimens from sub-Saharan Africa and Saudi Arabia, the link pages give fresh photographs and descriptions of
Major workers; Minor workers

This may be one of the world's most widely distributed, and perhaps most ubiquitous, tropical species. Hölldobler & Wilson (1990, page 118) picture specimens, from the Pacific Island of Samoa, which look very similar to those I have drawn. They also remark on it being notable for high local abundance and that it often 'extirpates' many other species of ant (pages 399-400). The drawing is from Wilson's (2003) review of the Pheidole of the New World.

Queen - photomontage collated from http://antweb.org/specimen.do?name=casent0104406.