Cephalotes hamulus

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Cephalotes hamulus
Scientific classification
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hymenoptera
Family: Formicidae
Subfamily: Myrmicinae
Tribe: Attini
Genus: Cephalotes
Species: C. hamulus
Binomial name
Cephalotes hamulus
(Roger, 1863)

MCZ ENT Cephalotes hamulus hal.jpg

MCZ ENT Cephalotes hamulus had.jpg

Specimen Label


This species has been collected in Haiti and the Dominican Republic. Mann remarked about his field experiences with this species (as Cryptocerus haemorrhoidalis) noting its lack of soldiers and details of its nesting habits: "Although many colonies of this ant were seen in Haiti, only one type of worker was found in them….The nests are usually in hollow twigs, but at Port au Prince several colonies were found nesting in fence-posts" (Wheeler and Mann 1914).


A member of the hamulus clade characterised by the following apomorphies: completely black body with longitudinal rugosities on the anterior fourth of the first gastral tergite and thin, short, appressed hairs on the gaster. (de Andrade and Baroni Urbani 1999)

Keys including this Species


Distribution based on Regional Taxon Lists

Neotropical Region: Dominican Republic (type locality), Greater Antilles, Haiti.

It has only been collected on Hispaniola.

Distribution based on AntMaps


Distribution based on AntWeb specimens

Check data from AntWeb




The following information is derived from Barry Bolton's New General Catalogue, a catalogue of the world's ants.

  • hamulus. Cryptocerus hamulus Roger, 1863a: 209 (w.) DOMINICAN REPUBLIC. Kempf, 1951: 149 (m.); De Andrade & Baroni Urbani, 1999: 86 (q.). Combination in Cryptocerus (Paracryptocerus): Emery, 1924d: 307; in Hypocryptocerus: Wheeler, W.M. 1936b: 201; in Zacryptocerus: Brandão, 1991: 384; in Cephalotes: De Andrade & Baroni Urbani, 1999: 84. Junior synonym of haemorrhoidalis: Emery, 1924d: 307; Menozzi & Russo, 1930: 162. Revived from synonymy as subspecies of haemorrhoidalis: Wheeler, W.M. 1936b: 201. Senior synonym of haytianus: Wheeler, W.M. 1936b: 201; Kempf, 1951: 149. Revived status as species and senior synonym of affinis: De Andrade & Baroni Urbani, 1999: 84.
  • haytianus. Cryptocerus hamulus var. haytianus Forel, 1901e: 337 (w.) HAITI. Junior synonym of haemorrhoidalis: Wheeler, W.M. & Mann, 1914: 38; of hamulus: Kempf, 1951: 149.
  • affinis. Hypocryptocerus haemorrhoidalis subsp. affinis Wheeler, W.M. 1936b: 202 (w.) HAITI. Combination in Zacryptocerus: Brandão, 1991: 384. Junior synonym of hamulus: De Andrade & Baroni Urbani, 1999: 85. See also: Kempf, 1951: 147.



From de Andrade and Baroni Urbani (1999) - Vertexal angles round, with crenulate margin; vertexal margin gently concave medially. Vertex with a median pair of small denticles and a trace of transverse carina. Frontal carinae reaching the middle of the eyes posteriorly, their sides expanded, not completely covering the cheeks. Cheeks posteriorly marginate. Anterior clypeal border concave in the middle and bearing two small lateral teeth. Eyes gently convex. Mandibles without lateral carinae, robust, and directed ventrally; the masticatory margin with a developed apical followed by a smaller preapical tooth and by 0-4 minute denticles or by an edentate margin.

Mesosoma robust, slightly convex in side view. Scapular angles bearing a pair of small denticles. Anterior pronotal border variably marked by a carina. Humeral angles with a pair of obtuse or stout spines directed anteriorly. Pronotal sides straight, ending in a small tooth visible in dorsal view. Promesonotal suture impressed laterally, morc superficial in the middle of the dorsum. Mesonotal teeth small, obtuse or round or absent. Propodeal suture deeply impressed dorsally. Propodeum with differentiated basal and declivous faces. Basal face slightly more than 1 /3 broader than long, with convex or obtuse sides anteriorly, straightening posteriorly and with or without a small denticle; declivous face as long as the basal face, with posteriorly slightly converging sides. Propodeal spines subequal to the basal face of the propodeum, thick and diverging.

Petiole ca. 1/2 broader than long, its anterior face truncate and slightly concave; its sides converging posteriorly, bearing a pair of anterior denticles and a pair of pointed teethmedially, both variable in size. Postpetiole broader than and as long as the petiole; postpetiolar spines broad and variably pointed, inserted anteriorly and curved backwards. Gaster with a membranaceous anterior crest, broad in most specimens, and reaching the first gastral stigma at maximum.

Legs. Fore coxae without a broad lobe or angle anteriorly. Hind femora slightly inflated in the middle; mid and hind basitarsi laterally compressed; their sides narrowing distally in side view.

Sculpture. Head minutely reticulate; vertexal area covered by broad impressions or irregular foveae gradually shallower towards the cheeks, sparser and small anteriorly. Frontal carinae reticulate and faintly rugulose on their sides. Ventral part of the head laterally covered by thick, regular striae. Hypostomal area deeply reticulate. Cheeks reticulate and rugulose on their posterior half.

Mesosoma, petiole and postpetiole covered by dense, longitudinal, irregular rugae, and by superficial, minute reticulation. The striae more regular on the pleurae. Declivous face of the propodeum partially or entirely covered by superficial to thick, longitudinal rugae, and reticulation variably impressed. First gastral tergite reticulate, with longitudinal rugosities on its anterior fourth and on its ventral marginal area. Corresponding sternite with superficial longitudinal rugosities on the sides, the rest with impressed reticulation and opaque, or faintly reticulate and slightly shining in the middle, and with sparse piligerous foveae.

Coxae with sparse, transversal or longitudinal rugosities and reticulate. Femora deeply reticulate and with sparse, thin, irregular, transversal rugae variably impressed; dorsally with a pair of distal, short, carinae more impressed on the mid and hind legs. Outer face of tibiae and basi tarsi with longitudinal, slightly anastomosing rugosities, otherwise reticulate.

Pilosity. Body with the following types of hairs: (1) truncate, erect to suberect, long on the vertexal area, on the mesosoma and on the pedicel, shorter on the anterior part of the head, on the gaster and legs; (2) thick and appressed, long on the vertexal area, on the mesosoma and pedicel; (3) thick, short, sparse, appressed on the anterior half of the head, thinner on the gaster and on the legs; (4) thin, very long and pointed on the sternites.

Colour. Black. Frontal carinae, scapes and tarsomeres dark orange to light brown. Vertexal area, mesosoma and pedicel with some golden reflexes.

Measurements (in mm) and indices: TL 6.16-7.16; HL 1.46-1.68; HW 1.68-1.96; EL 0.44-0.52; PW 1.52-1.80; PeW 0.72-0.86; PpW 0.96-1.08; HBaL 0.68-0.76; HBaW 0.16-0.20; CI 114.6-116.6; PI 108.8-111.3; PPeI 200.0-233.3; PPpI 158.3-175.0; HBaI 23.5-26.3.


From de Andrade and Baroni Urbani (1999): (previously undescribed, tentative specific attribution) - Differing from Cephalotes auricomus in the following characters: head less convex, vertexal angles convex and broader. Vertex with a longer pair of median denticles and with the transversal carina more impressed.

Mesosoma. Humeral angles with a pair of longer anterior teeth. Pronotal crest strongly marked by a row of higher, pointed denticles.

Petiole with the anterior face separate from the posterior one by a visible carina interrupted medially. Postpetiole and gaster missing.

Legs. Fore coxae without a broad lobe or angle anteriorly. Hind femora slightly inflated in the middle; mid and hind basitarsi laterally compressed; their sides narrowing distally in side view.

Sculpture. Vertexal area superficially reticulate, irregularly foveolate-rugulose, the foveae more regular and small anteriorly. Ventral side of the head punctate and covered by thick, regular striae. Cheeks reticulate and irregularly rugose.

Mesosoma and petiole reticulate and covered by thick, irregular foveae and rugosities, the rugosities more longitudinally oriented on the mesonotum, scutellum, propodeum and petiole. Lower mesopleurae and metapleurae reticulate and with thin rugosities, the rugosities more regular and sparser on the metapleurae. Declivous face of the propodeum reticulate and with short rugosities on the middle only: longitudinal superiorly and transversal inferiorly.

Legs reticulate; outer face of the tibiae with thin, irregular, longitudinal rugosities.

Pilosity. Body with the following types of hairs: (1 ) truncate, erect to sub erect, long on the vertexal area, on the mesosoma and on the petiole, shorter on the anterior part of the head and on the legs; (2) thick and decumbent, long on the vertexal area, on the mesosoma and petiole, shorter on the anterior half of the head, dense on the middle of the basal face of the propodeum; (3) thin, short, sparse, appressed on the legs.

Colour. Black. Frontal carinae and antennae dark orange-ferrugineous. Body with silvery reflexes given by the pilosity.

Measurements (in mm) and indices: TL (gaster missing in the unique specimen; length of the gaster measured on the complete print left in the glue) - 9.18; HL 1.96; HW 2.12; EL 0.56; PW 2.08; PeW 0.76; HBaL 0.76; HBa W 0.22; CI 108.2; PI 101.9; PPe! 273.7; HBaI 28.9.


Kempf (1951) - Head, thorax, coxae, peduncle fuscous brown. Legs, tips of mandibles, scape and gaster yellowish brown. Funiculus light brown. Mandibles with a distinct apical and preapical tooth; the following teeth vestigial. Head transverse; the median head length shorter than the interocular width. Frontal carinae divergent, fading out above the eyes. Antennal scrobe obsolescent. Eyes large, their maximum diameter sub equal to half of the median head length. Occiput evenly rounded transversely without forming distinct lateralangles. Integument finely reticulate-punctate. Transverse rugae between the upper border of the eyes and the front. Scape about half as long as the second funicular segment. Sides of pronotum diverging behind, with a distinct scapular tooth. A vestigial transverse carina across the pronotum. Laterotergite excavated beneath just above the fore coxae. Scutum and scutellum considerably convex. Mayrian furrows deeply impressed. Upper mesopleura strongly convex. Epinotum transverse, the posterior corners of the basal face dentate. Integument finely reticulate-punctate, irregularly rugulose. Petiole about as long as wide, with a vestigial tooth on each side. Postpetiole flat above, subquadrate, with a tubercular tooth on each side. Gaster finely reticulate, subfulgid. The genitalia have been lost. Pile (sic) fulvous and erect, abundant and conspicuous on head and thorax; sparser and appressed on gaster and legs. Wings slightly infumated; veins brunneous. Fore wing with a closed and appendiculate marginal cell, and a transverse cubital vein. Submarginal cell short. Transverse median vein about half as long as the second abscissa of the median vein.

Note: the sole known male of this species in the MCZC lacks the last 6 gastral segments and the genitalia.

de Andrade and Baroni Urbani (1999): Measurements (in mm) and indices: TL 5.62 (excluding gastral segments 2-8 missing in the only available specimen); HL 0.94; HW 1.16; EL 0.46; PW 11.08; PeW 0.48; Pp W 0.52; HBaL 0.85; HBa W 0.11; CI 123.4; PI 107.4; PPeI 225.0; PPpI 207.7; HBal 12.9.

Type Material

de Andrade and Baroni Urbani (1999) - one syntype worker labelled " Cryptc. hamulus, S. Domingo, Type" in the Museo Civico di Storia Naturale, Genoa, examined. Additional syntype workers presumably in the "Zoologisches Museum an der Humboldt-Universitat", Berlin.


  • Brandão, C. R. F. 1991. Adendos ao catálogo abreviado das formigas da região Neotropical (Hymenoptera: Formicidae). Rev. Bras. Entomol. 35: 319-412 (page 384, Combination in Zacryptocerus)
  • De Andrade, M. L.; Baroni Urbani, C. 1999. Diversity and adaptation in the ant genus Cephalotes, past and present. Stuttg. Beitr. Naturk. Ser. B (Geol. Paläontol.) 271: 1-889 (page 86, queen described; page 84, Combination in Cephalotes, Raised to species and senior synonym of affinis)
  • Emery, C. 1924f [1922]. Hymenoptera. Fam. Formicidae. Subfam. Myrmicinae. [concl.]. Genera Insectorum 174C: 207-397 (page 307, Combination in Cryptocerus (Paracryptocerus), Junior synonym of haemorrhoidalis)
  • Kempf, W. W. 1951. A taxonomic study on the ant tribe Cephalotini (Hymenoptera: Formicidae). Rev. Entomol. (Rio J.) 22: 1-244 (page 149, male described, Senior synonym of haytianus)
  • Menozzi, C.; Russo, G. 1930. Contributo alla conoscenza della mirmecofauna della Repubblica Dominicana (Antille). Boll. Lab. Zool. Gen. Agrar. R. Sc. Super. Agric. 24: 148-173 (page 162, Junior synonym of haemorrhoidalis)
  • Roger, J. 1863a. Die neu aufgeführten Gattungen und Arten meines Formiciden-Verzeichnisses nebst Ergänzung einiger früher gegebenen Beschreibungen. Berl. Entomol. Z. 7: 131-214 (page 209, worker described)
  • Wheeler, W. M. 1936c. Ants from Hispaniola and Mona Island. Bull. Mus. Comp. Zool. 80: 195-211 (page 201, Combination in Hypocryptocerus, Revived from synonymy, status as subspecies of haemorrhoidalis, Senior synonym of haytianus)