The pallens species group

(Figs. 37, 38, 39)

The pallens group was proposed by De Andrade and Baroni Urbani (1999) with 10 species.It includesC.jamaicensis, C.pallens, C.patellaris,

C. porrasi, C. variansand thenew species describedby De AndradeinDe Andradeand Baroni Urbani (1999) ( C.decolor, C.decoloratus, C.pallidoides, C. pallidus, and C. pellans). Of these species, only five occur in Brazil – C. pallens, C. pallidoides, C. pallidus, C. patellaris, andC. pellans .

This is the mostmorphologically homogeneous group of Cephalotes . Therefore, isthe most challenging group regarding species delimitation, especially if the workers are theonly casteavailable. Inthe identification key for workers, De Andrade and Baroni Urbani (1999) provideda note about this difficulty and recommended verification of the soldier’s identification key before applying a name.

In addition to the characters employed by De Andrade and Baroni Urbani (1999), here we provide an illustrated identification key for workers based on characters as the shape of frontal carinae in relation to eyes, and sculpture patterns on pleura. Regarding the identification key for soldiers, the most informative characters are the sculpture and pilosity patterns.

The pallens group is sister to the clade formed by the grandinosus and pinelii groups (Fig. 54), with all of these groups sharing a worker body shape that is strongly flattened dorsoventrally.

Diagnosis: In worker, body strongly flatteneddorsoventrally. Body colorreddish brown.In frontal view, vertexalcorner extending laterally overhangingtheeye (Fig. 2d). In soldier, infrontalview, cephalicdorsum completelycovering the mandibles to form a “dish” head type (Fig. 38).

Brazilian species of pallens group

Cephalotes pallens (Klug, 1824)

Obsolete combinations: Cryptocerus pallens, Zacryptocerus pallens

= Cephalotes araneolus (Smith, 1853)

Obsolete combination: Cryptocerus araneolus

= Cephalotes discocephalus Smith, 1853

Obsolete combination: Cryptocerus discocephalus Cephalotes pallidoides De Andrade, 1999

Cephalotes pallidus De Andrade, 1999

Cephalotes patellaris (Mayr, 1866)

Obsolete combination: Cryptocerus patellaris Cephalotes pellans De Andrade, 1999

Key to the identification of Brazilian species of the pallens group of Cephalotes based on workers

(Figs. 37 a-i)

1 In dorsal view, lamellarexpansions of thepropodeum witha symmetrical posterior notch on both sides; an additional notch may be present anteriorly, but in this case, it is alwayssymmetrical. The notch is never present onone sideonlyorare asymmetrical (Fig. 37g)................... C. pallens

1’ Indorsal view,lamellar expansionsof propodeum withoutnotches.If any, theyare asymmetric, probably causedbybreaking (Fig.37h).......................2

2 In lateral view, frontal carinae narrow, ending over the eyes, so that the posterior portion of the eyes is confluent with the dorsal face of thehead (Fig. 37a)..................................................................................................3

2’ In lateral view, frontal carinae broad, extending beyond eyes length, separating eyes from dorsal face of head (Fig. 37b, c)................................4

3 Lateral surface of the mesosoma rugose (Fig. 37f).............. C. pellans

3’ Lateral surface of the mesosoma microalveolate; some incomplete rugosities maybepresent (Fig. 37i)................................................... C. pallidoides

4 In ventral view, headrugose (Fig.37d).............................................. C. patellaris

4’ In ventral view, head totally microalveolate, without rugosities (Fig.37e).......................................................................................................... C. pallidus

Key to the identification of Brazilian species of the pallens group of Cephalotes based on soldiers

(Figs. 38 a-i)

1 Cephalic dish irregularlyareolate-rugose (Fig.38a)......................... C. pallidus

1’ Cephalicdishregularlyalveolate (Fig.38b) orfoveate (Fig.38c)...........................2

2 Cephalicdishwitherecttosuberecthairs(Fig.38d,g)...................................................3

2’ Cephalicdishwithsubdecumbenttoappressedhairs (Fig.38e, f).......................4

3 Cephalic dish with amedianprotuberance (Fig.38d)................... C. patellaris

3’ Cephalic dishflat or witha weak medianprotuberance (Fig. 38g).......... .................................................................................................................. C. pallidoides

4 Cephalicdish without a median protuberance (Fig. 38e). Translucent edges of the cephalic disc internally with long hairs larger than the diameter of the foveae (Fig. 38e). Declivous face of propodeum always rugose (Fig. 38h)...................................................................................... C. pellans

4’ Cephalic dish with a median protuberance, weakly developed (Fig. 38f). Translucent edges of the cephalic disc internally with short hairs smaller than the diameter of the foveae (Fig. 38f). Declivous face of propodeum predominantlymicroalveolate, some tiny rugosities can be present (Fig. 38i)............................................................................... C.pallens