The pusillus species group

(Figs. 49, 50, 51)

The spinosus group by Kempf (1951) comprised the De Andrade and Baroni Urbani’s laminatus and pusillus groups, which share the followingcharacters:anterolateralpronotum angulate, separatefrom the pronotal expansions; propodeum with twopairs of spinesor denticles, with the posterior one longer thananterior; dorsal anddeclivous faces of propodeum differentiated, meeting in a distinct propodeal angle; gaster with distinct anterolateral lamellate borders.

Despite the shared characters,De Andradeand Baroni Urbani (1999) separated the former Kempf’sspinosus groupinlaminatus andpusillus groups. Thesynapomorphy forthepusillus group is the absence of fine reticulation on thecephalic ventralface and theabsenceof angulate hind femora. However, both characters are the same in the laminatus group, which includes the remaining species of Kempf’s spinosus group and C.duckei, that hadbeen consideredan isolated speciesby Kempf (1951). The synapomorphy for laminatus group, according to De Andrade and Baroni Urbani (1999), is the vertexal corners with a truncate lamella, butthis character is alsopresent in other groups, including thepusillus group. The characters used by Kempf (1951) tojoin the members of the pusillus and laminatus groups within the spinosus group seem more robust. Concordantly, the molecular phylogeny by Priceet al. (2016, see their Fig. S3) recovered C. pusillus and C. columbicus within the laminatus group, rendering the laminatus group paraphyletic. Based on this molecular and morphological evidence, we here recognize the members of pusillus and laminatus groups as a unique group, under the name “ pusillus ”, since C. pusillus is the oldest species in the group (Fig. 54).

Most species inthisgroup occurin Brazil,except for C.christopherseni, known so far only from Colombia, Venezuela, and Panama, and for C. columbicus, known from Colombia and Venezuela.

Diagnosis: In workers and soldiers, dorsal and declivous faces of propodeum differentiated, meeting in a distinct propodeal angle; propodeum with two pairs of spines, the posterior longer than the anterior (Fig. 2f). Mid and hind basitarsi not flattened.

Brazilian species of pusillus group

Cephalotes duckei (Forel, 1906)

Obsolete combination: Cryptocerus duckei

Cephalotes inaequalis (Mann, 1916) Obsolete combination: Cryptocerus inaequalis

Cephalotes laminatus (Smith, 1860) Obsolete combination: Cryptocerus laminatus

Cephalotes minutus (Fabricius, 1804) Obsolete combination: Cryptocerus minutus = Cephalotes cognatus (Smith, 1862) Obsolete combination: Cryptocerus cognatus = Cephalotes exiguus (Smith, 1867) Obsolete combination: Cryptocerus exiguus = Cephalotes quadrimaculatus (Klug, 1824) Obsolete combination: Cryptocerus quadrimaculatus = Cephalotes volxemi (Emery, 1878) Obsolete combination: Cryptocerus volxemi

Cephalotes pusillus (Klug, 1824) Obsolete combination: Cryptocerus pusillus = Cephalotes caustica (Pohl & Kollar, 1832) Obsolete combination: Formica caustica = Cephalotes elongatus (Klug, 1824) Obsolete combination: Cryptocerus elongatus = Cephalotes obtusus (Smith, 1858) Obsolete combination: Cryptocerus obtusus = Cephalotes pusillus brevispinosa (Santschi, 1921) Obsolete combination: Cryptocerus pusillus brevispinosa

Cephalotes simillimus (Kempf, 1951) Obsolete combination: Paracryptocerus simillimus

Cephalotes spinosus (Mayr, 1862) Obsolete combination: Cryptocerus spinosus = Cephalotes laminatus peruvianus (Forel, 1911) Obsolete combination: Cryptocerus laminatus peruvianus = Cephalotes punctatus (Mayr, 1862) Obsolete combination: Cryptocerus punctatus

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

(Figs. 49 a-l)

1 In dorsal view, petiole subrectangular, a small denticle of the same color as petiole can be present (Fig. 49g)..................................... C. pusillus

1’ In dorsal view, petiole of another shape, with spines with translucent tips (Fig. 49 d-f, h-k)...............................................................................................2

2 Indorsalview,mesonotalspinesabsent (Fig.49d)......................... C. spinosus

2’ In dorsal view, mesonotal spines present (Fig. 49c, e, h, i).................3

3 Inposterodorsalview,declivousfaceofthepropodeumwithwell-marked longitudinal striaeoccupying the entiresurface (Fig. 49j)........... C. minutus

3’ In posterodorsal view, declivous face of propodeum without longitudinal striae; if any, they are weakly marked and not occupying the entire surface (Fig. 49k, l).............................................................................4

4 In dorsal view, posterior propodeal spines curved anteriorly (Fig. 49e)... .................................................................................................................................. C. duckei

4’ In dorsal view, posterior propodeal spines curved posteriorly (Fig. 49c, d, h, i)......................................................................................................5

5 In frontal view, the distance between the eyes is shorter or at most equal to the length of the head (Fig. 49a).............................. C. simillimus

5’ Infrontal view, distance between eyes greater than head length (Fig. 49b)..................................................................................................................6

6 In dorsal view, propodeal groove weakly impressed; marked on the sides but absent medially (Fig. 49h).......................................... C. laminatus

6’ In dorsal view, propodeal groove strongly impressed on the entire dorsum (Fig. 49i)............................................................................. C. inaequalis Key to the identification of Brazilian species of the pusillus group of Cephalotes based on soldiers

(Figs. 50 a-i)

1 In dorsal view, petiole subrectangular, without spines; at most with a very tiny denticle (Fig. 50a)........................................................... C. pusillus

1’ In dorsal view, petiole of anothershape; if subrectangular, there are spines with translucent tips (Fig. 50 b-g)........................................................ 2

2 Margins of declivousface of propodeumwith laterallamellar expansions (Fig. 50c, f, i)............................................................................................................3

2’ Margins of declivous face of propodeum without lateral lamellar expansions (Fig. 50b, d, e, g, h)..........................................................................4

3 In dorsal view, posterior propodeal spines curved anteriorly (Fig. 50c)... .................................................................................................................................. C. duckei 3’ In dorsal view, posterior propodeal spines curved posteriorly (Fig. 50f)........................................................................................... C. simillimus

4 In dorsal view, gastral lamellae widthshorter than or equal to thewidth of the postpetiolar spines (Fig. 50b - yellow arrows)..................... C. minutus

4’ In dorsal view, gastral lamellae width is at least twice the width of the postpetiolar spines (Fig. 50d, e, g - yellow arrows)..............................5

5 In dorsal view, gastral lamellae glabrous (Fig. 50e)......... C. spinosus

5’ In dorsal view, gastral lamellae with hairs (Fig. 50d, g)........................6

6 Posterior propodeal spines bifurcated, spines black with yellowish tips (Fig. 50d).................................................................................... C. inaequalis

6’ Posterior propodeal spines not bifurcated, spines completely black (Fig. 50g).................................................................................................... C. laminatus