Cylindromyrmex striatus

De Andrade (1998) - A rarely collected species occuring only in the northern part of South America. C. striatus and C. whymperi are allopatric. Overal & Bandeira (1985) found specimens of striatus in nests of Nasutitermes sp. and N. surinamensis.

Identification
De Andrade (1998) - A Cylindromyrmex species belonging to the striatus clade, resulting as sister species of Cylindromyrmex whymperi in my analysis, but differing from it by the thinner body striation, by the posterior third of the head dorsum with more than 34 striae instead of 25 at most.

The similarities between striatus and whymperi and the small number of striatus specimens available for study is one of the reasons for which whymperi had been considered a junior synonymy of striatus. The sole male of striatus I examined is also very similar to whymperi. Few differences are visible in their genitalia.

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil, French Guiana, Guyana, Suriname, Venezuela.

Nomenclature

 *  striatus. Cylindromyrmex striatus Mayr, 1870b: 967 (q.) SURINAM. Mayr, 1887: 545 (w.m.). See also: De Andrade, 1998a: 605.

Description
De Andrade (1998):

Worker
TL 6.18-6.56; HL 1.24-1.28; HW 0.99-1.04; EL 0.35-0.36; SL 0.52-0.56; SW 0.15-0.16; WL 1.52-1.72; PW 0.72-0.75; PeL 0.65-0.75; Pew 0.59-0.65; HFeL 0.72-0.78; HFeW 0.25-0.28; HTiL 0.71-0.80; HTiW 0.19-0.21; HBaL 0.52; HBaW 0.09; CI 79.8-81.2; SI 28.6-28.8; HFeI 34.7-35.9; HTiI 26.2-26.8; HBaI 17.3.

Head 1/5 longer than broad. Sides of the head subparallel. Occiput low. Vertexal angles round. Frontal carinae about half broad as the maximum head width. Sides of the frontal carinae anteriorly diverging and posteriorly gently convex. Dorsum of the frontal carinae with an impressed, short median sulcus anteriorly. Frontal carinae not reaching the anterior border of the clypeus. Compound eyes large, convex and slightly behind the mid line of the head. Ocelli well defined. Scapes reaching the anterior border of the eyes. Proximal fifth of the scapes 1/2 narrower than the remaining parts. Mandibles flat and short. Mandibles laterally angulate at the base. Masticatory margin of the mandibles with a set of 4 irregular denticles followed by an apical tooth.

Mesosoma gently convex dorsally and as long as or slightlly longer than the head (mandibles included). Pronotum with subparallel sides. Mesonotum narrower than pronotum. Propodeal sides slightly convex. Basal face of the propodeum separated from the declivous one by a marked margin converging medially.

Petiole slightly longer than broad, anteriorly truncate and dorsally convex. Petiolar sides gently diverging backwards. Ventral process of the petiole small and triangular. Postpetiole slightly more than 1/4 broader than long. Postpetiolar sides gently convex. Postpetiolar sternite antero-medially with a marked triangular “lip” pointing backwards. Postpetiole in dorsal view antero-laterally angulate. Pygidium as in Cylindromyrmex whymperi.

Legs. Femora and tibiae not inflated. Hind basitarsi long. ca. 1.4 shorter than the maximum length of the hind tibiae. Outer apical edge of the hind and of the mid basitarsi with 6 or 7 spine-like setae.

Sculpture. Head mesosoma and postpetiole with thinner striation than those in whymperi. Posterior third of the head dorsum and frontal carinae with longitudinal striae, thinner on the anterior part of the frontal carinae. Sides of the head dorsum in front of the compound eyes with thinner striae than on the anterior part of the frontal carinae. Ventral part of the head antero-laterally with longitudinal striae: remaining pans of the ventral part of the head smooth and with minute, superficial piligerous punctures. Mesosoma with longitudinal striae thicker than those on the posterior half of the head dorsum. Pronotum with 20-22 striae. Propodeum with ca. 17 striae. Pleurae with thin longitudinal striae as those in front of the compound eyes, the striae thicker on the upper pro- and metapleurae. Petiolar dorsum with 12-14 striae thicker than those on the mesosoma. Petiolar side minutely reticulate and with less regular and thinner striae than those on it dorsum. Declivous face of the propodeum and anterior face of the petiole minutely and superficially reticulate. Dorsum of the postpetiole with ca. 29-30 striae similar to those on the mesosoma. Postpetiolar sternite smooth and with small, sparse piligerous foveae. First, second and third gastric tergites and first gastric sternite smooth and with sparse punctuation. Remaining gastric segment reticulate-punctate. Hind coxae with few thin, longitudinal striae. Legs with very superficial, minute punctures.

Pilosity as in whymperi and Cylindromyrmex brasiliensis.

Colour black and shining with lighter lega. Tibiae of three pairs of leg yellowish with the distal borders brown.

Queen
TL 7.50-7 .72; HL 1.30-1.32; HW 1.00; EL 0.40-0.42; SL 0.50- 0.51; SW 0.16; WL 2.08- 2.12; PW 0.76-0.80; PeL 0.67-0.70; PeW 0.63; HFeL 0.68; HFeW 0.27; HTiL 0.67-0.68; HTiW 0.21-0.22; HBaL 0.53; HBaW 0.09; Cl 75.7-76.9; SI 31.4-32.0; HFel 39.7; HTiI 30.9-32.8; HBal 17.0.

Similar to the worker but differing from it in the following peculiarities: mesosoma broad medially: parapsidal furrows impressed: posterior part of the head dorsum with slightly thicker striae than on those the anterior part: pronotum with 22-24 longitudinal striae slightly thicker than those on the posterior part of the head dorsum: mesonotum smooth to weakly striated medially, the striae very thin and incomplete: scutellum with 8-10 striae similar to those on the pronotum: dorsum of the propodeum with 18-20 striae similar to those on the pronotum; petiolar dorsum with 13-15 longitudinal striae thicker than those on the pronotum; postpetiolar dorsum with 30-34 longitudinal striae lightly thinner than those on the pronotum.

Male
TL 7.74; HL 1.05; HW 1.00; SL 0.26; SW 0.15; WL 02.54; PeL 0.73; PeW 0.68; HFeL 0.95; HFeW 0.20; HTiL 0.81; HTiW 0.17; HBaL 0.62; HBaW 0.08; CI 95.2; SI 57.7; HFeI 21.0; HTiI 21.0; HBaI 12.9.

Very similar to the one of Cylindromyrmex whymperi but differing from it in the following details: head (eyes excluded) slightly longer than broad; vertexal angles less convex. Scutellum with the side less converging and with the posterior border less truncate.

Sculpture. Ventral part of the head smooth and with few, small piligerous foveae. Scutellum, propleurae, petiole, postpetiole, gaster and legs smooth and with minute, superficial punctures, more impressed on the last gastric segments. Ventral border of the propleurae with two-three longitudinal striae.

Colour. Head and mesosoma dark brown-black and shining. Gaster brown. Mandibles, antennae and legs yellow to light brown. The specimen in question is immature.

Type Material
Two gynes labelled: "Surinam. Coll. G. Mayr. striatus. G. Mayr, Type": one gyne labeled: "Surinam. M. Haab, Collect. G. Mayr. striatus. G. Mayr. examined.