Contents Contents The Ants of Egypt

Genus Messor (Forel, 1890a)

Raised to genus by Bingham, 1903, includes members previously placed in Cratomyrmex Emery.


Diagnostic Features - Granivorous ants, most strongly polymorphic. Ventral surface of head with a psammaphore (a basket-like array of long, curved hairs beneath the head, used to carry sand). Mandibles strongly curved, usually dentate in smaller workers. Antennae 12-segmented. Propodeum armed with a pair of blunt teeth. Node of petiole emarginate above in large workers. Illustrations of West African species are not available so those below are given as a guide.

The original genus definition, as a subgenus of Aphaenogaster, Forel (1890a: lxviii) is at {original description}. Emery's (1892d) definition of Cratomyrmex is at {original description}.

André (1883a: 350) gave a key to the species then known from Europe and North Africa this is at {original description}. Finzi (1936: 160) gave a key to the species then known from Egypt; this is at {original description}.

Key to workers from Egypt - derived largely from Finzi (1936)

1 {Messor rufotestaceous antenna}Funiculus with last four segments elongated; body slender and smooth; colour yellow, gaster brownish; TL max 7.5 mm North Africa through Sinai to Syria - rufotestaceus
-- {Messor barbarus antenna}Funiculus with last four segments not elongated; colour other than yellow 2
2 {Messor arenarius antenna}First segment of funiculus shorter than second 3
-- First segment of funiculus at least as long as second 4
. First segment of funiculus shorter than second .
3 Messor arenariusTL 7-16 mm; declivity of mesonotum obviously convex and declivity of propodeum abrupt (105-110°); propodeum with distinct teeth Across North Africa into Syria - arenarius
-- Messor niloticusTL 12-16 mm; posterior declivity of mesonotum less convex and of propodeum less abrupt (120-130°); propodeum with teeth reduced to denticles; petiole with lower profile than most other species; head, alitrunk and pedicel matt, densely reticulo-punctate; sides of head longitudinally striate, plus a detached pair between the frontal carinae running towards the vertex; generally red, edges of clypeus and frontal carinae, scape, sometimes lower alitrunk, part of gaster blackish-brown to black, appendages lighter (media shown)
Egypt - niloticus
. First segment of funiculus at least as long as second .
4 {Messor rugosus major}Occiput with more or less visible transverse striations, alitrunk deeply striated; petiole profile a low triangle; gaster smooth and shiny; TL 6 mm rugosus
-- Occiput with no or only longitudinal striations 5
5 {Messor foreli propodeum}Propodeum with teeth or spines 6
-- {Messor barbarus propodeum}Propodeum unarmed or with minute denticles/spines (when generally red in colour) 9
. Propodeum with at least pronounced tubercles .
6 Messor ebeninusPropodeum with large teeth (not spines), quite strong but obtuse; body form slender; head and gaster brilliantly shiny; generally ebony black but alitrunk may be very slightly reddish in minor workers, tibiae & tarsi yellowish; alitrunk quite deeply rugose; opaque; TL 4.1-10 mm - NOTE - the foregoing based on Forel's description, later authors appear to have the teeth reduced to tubercles; the specimen shown has broad propodeal teeth (semirufus ebeninus) Egypt to Syria - ebeninus
-- Propodeum with distinct spines 7
7 {Messor aegyptiacus}At least the alitrunk reddish; gaster black; pronotum densely granular, petiole finely rugose, gaster weakly granular basally, slightly shiny; propodeum with raised spines, sometimes arcuate; small TL max 6 mm Algeria east to Egypt - aegyptiacus
-- Wholly black 8
8 Messor foreliPropodeum with flat spines, ends downturned; occipitum shiny, with sparse small rounded fossettes (aegyptiacus foreli) Algeria, Tunisia and Sinai - foreli
-- {Messor aegyptiacus felah}Head with longitudinal striations reaching the occiput; longer propodeal spines with a narrower base than type aegyptiacus Egypt only - aegyptiacus felah
-- Head black, alitrunk usually reddish with superficial rugosity, sometimes lightly shiny; appendages reddish to rust [Santschi, 1927c: 240], reported from Alexandria with reservations by Finzi (1936) - aralocaspius (Ruzsky, 1902c: 20, worker) occurs only in east-central Asia and minor (André, 1883b: 355, worker & queen) from North-east Africa, other than the type form from Italy, type location from Corsica (André, 1883b: 355, worker & queen) - rather small, TL maximum 7.0 mm [questionable diagnosis, possibly a one-off immigrant minor from Italy] - Egypt (Alexandria), Turkestan - minor aralocaspius tamerlani
BUT see aegyptiacus
-- Description imprecise (Finzi, 1936: 158); head flatter, longer psammophore; eyes larger, length = the distance eyes forward of occiput; much longer propodeal spines than type aegypticaus; head reddish, alitrunk dark brown (Forel, 1913d, as race of aegyptiacus); TL 4-12 mm Egypt - aegyptiacus sahlbergi
-- {messor_eglalae}Unicolorous black; TL 8.8 (minor worker ?); head with dense granulate sculpturation Egypt - eglalae
return to key Propodeum unarmed or with minute spines/denticles .
9 Messor structorWhole of body covered with dense pilosity; head and alitrunk strongly striate, matt; propodeum unarmed; varies from yellow brown to brown black, with appendages all reddish; TL 3.5-10 mm
France east to Central Asia - structor
-- Pilosity sparse to none 10
10 {Messor medioruber}Tl 3-6 mm; head of major relatively small; type form with brown head (queen black); alitrunk finely sculptured; basal segment of gaster glabrous, smooth and shiny; scape reaches occiput; clearly higher petiole node Tunisia, Algeria & "Arabian Desert near Cairo" - medioruber
-- {short description of image}subspecies generally red; propodeum seemingly with angular tubercles or minute spines rather than edentate medioruber ssp maurus
-- Petiole only moderately high 11
11 {Messor concolor}Propodeum with obtuse transition from dorsum to declivity; apparently overall darker than type barbarus and head not lighter/more red than rest; Syria, Crete & Sinai (?) - concolor
-- Propodeum with acute transition from dorsum to declivity 12
12 {sMessor barbarus s.s.}Type head particularly occiput smooth or near smooth and shiny, alitrunk quite heavily sculptured; propodeum often unarmed; TL 4-12 mm southern Europe and circum-Mediterranean - barbarus sensu lato
-- Messor maculifronsOverall brown-red or brownish-red; head reddish, patches on head and mesonotum, also parts of legs and gaster more brown, antennae and rest of legs clear brownish red; propodeum with subvertical declivity and distinct metanotal groove; TL 5-10 mm; (semirufus maculifrons) Egypt, Syria into Caucasus - maculifrons
-- {sMessor barbarus s.s.}Overall smooth or near smooth and shiny, alitrunk weakly sculptured; propodeum often unarmed; TL 4-8.5 mm; unicolourous red-brown Egypt & Tunisia - binodis
©2005, 2006, 2008, 2009, 2010, 2015, 2019 - Brian Taylor CBiol FRSB FRES
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