Dorylus (Anomma) sjoestedti Emery new status

Type locality Cameroun (Dorylus nigricans ssp sjöstedti, Emery, 1899e: 461, worker; soldier by Santschi, 1912b: 160; queen by Raignier & van Boven, 1955: 98); workers and queen known (as in Bolton, 1995, but Emery appears to have described the "major") .

Emery's (1899e) description is at .

Raignier & van Boven (1955, p 26) cite the original descriptions by Emery (1899e) and Santschi (1912b). Emery compared the specimen with arcens - head entirely matt and narrowed to the rear as arcens; posterior corners more pointed; petiole strongly resembling that of wilverthi narrower and more elongated. Santschi noted the sjoestedti funiculus had the penultimate segment three times as long as wide and twice the previous segment; but Raignier & van Boven found this incorrect with the segment no more than twice as long as wide, and often less.

At Yangambi, Raignier & van Boven (1955, p 72-74) made seven collections of sjoestedti, totalling 195 specimens. Their descriptive notes give -
TL range ca 13-3.6 mm; overall colour red-brown to red-black; major with head matt, sometimes shiny posteriorly; CI 100 or slightly more; posterior with sharp prominent angles; petiole with small posteroventral angles (not consistently so).

Wheeler (1922) listed other findings from Cameroun (Yukuduma, by Funck; Grand Batanga and Lolodorf by G. Schwab); and Congo (at Samkita, by F. Faure).

Polymorphism (major, media 1 and media 4/minima)

The photomontages are of specimens from Central African Republic, Bozo, collector Degallier, 18.xii.1991. The specimen denoted as the minima may be the smallest intermediate, or minor.

The various morphs are shown in detail on the Dorylus (Anomma) sjoestedti morphs page.

Full new description - Central Africa & Uganda specimens
Overall - shiny matt head and gaster dark chestnut, head with very dark anterior margin; alitrunk, legs and funiculi lighter to chestnut-orange, light apical bands on gaster
TL 11.1-11.8 HW 2.75 HL 2.55 HD 2.0 CI xx SL 1.75 SI xx AL 3.75 PW 0.8 PetL 1.0 GL 3.7 MFL 2.5
Head - trapezoidal, widest in anterior quarter; sides tapering throughout posterior two-thirds to about half maximum width; posterior margin quite deep, angles sharp; sculpturation finely and entirely spiculate, near matte, no hair pits; median line distinct, slightly raised on occiput; clypeal margin near straight, with fine long median hair and flanking medium fine hairs; mandibles long, slender and sharp, basal tooth triangular and large; scape near straight only slightly out curved, slender; funiculus long and slender, with short pilosity; head profile quite bulbous, venter less convex than dorsum; hairs none, no pilosity
Alitrunk - moderately domed with shallow "saddle", below pronotum level; spiracle subcircular; propodeum smooth flat curve to short sub-vertical declivity; metapleural gland with upper flange distinctly longer than lower; sculpturation as head micropilosity on entire dorsum.
Petiole - anterior 1/4 45° slope, dorsum flat, posterior subvertical, small posteroventral protrusions but these are visible from above; dorsal face widening 75% from front to back with processes visible; spiracles small but protruding in dorsal view; sculpturation as alitrunk; no hairs on posterodorsal margin.
Gaster - quite shiny; only minor waisting; a few fine hairs on dorsal margins, numerous all over ventrally, long and coarse on basal segment.
Legs - coxae quite slender at base; femora long and slender; matte with quite dense fine pilosity; tibiae long, slender, dense fine pilosity; tarsi long, slender, dense fine pilosity, slender claws.

Minima morph (may be the media 4 morph)
Head shiny, densely spiculate but that near effaced, colour dark orange brown; scapes with fine decumbent pilosity; dorsum with sparse short decumbent golden pilosity.