Eurhopalothrix lenkoi

This species has been found nesting in a bromeliaceous plant growing on the soil.

Identification
Longino (2013): This species has the posterior face of the propodeum with large foliaceous crests instead of acute propodeal spines, a trait shared with Eurhopalothrix pilulifera from Central America. It differs in the much larger body size and the tooth-like development of the posterior face of the petiolar node. The head shape and pilosity patterns are much like Eurhopalothrix gravis. Measurements for workers of this species, as reported in Kempf (1967) are HW 0.91–0.99, HL 0.86–0.93, CI 100–106, SLI 9–12 (n=7). Measurements for the queen are HW 1.17, HL 1.12, CI 105. This is the largest New World species so far reported, with E. gravis being second largest. Queen HW is 1.22 x worker HW, the largest difference of any New World species. Most species for which queens and workers are known fall on a single line of allometry, with queen HW 1–1.1 x worker HW. The two largest species, E. gravis and E. lenkoi, deviate from the line with ratios 1.12 and 1.21, respectively.

Key to New World Eurhopalothrix

Distribution
Brazil (Sao Paulo)

Distribution based on Regional Taxon Lists
Neotropical Region: Brazil.

Nomenclature

 *  lenkoi. Eurhopalothrix lenkoi Kempf, 1967d: 358, figs. 6, 7 (w.q.) BRAZIL.

Worker
(holotype). - Total length 4.1 (3.7-4.2) mm; head length 0.93 (0.86-0.93) mm; head width 0.96 (0.91-0.99) mm; thorax length 1.07 (1.02-1.17) mm. Cephalic index 100-106. Reddish brown; middle of cephalic dorsum, underside of head, disc of pronotum, metapleura and epinotum, petiolar and postpetiolar node, gaster more or less strongly infuscated; antennal scrobe, laterotergite of pronotum, mesonotum and mesopleura and legs contrasting by their light, yellowish brown color. Body very finely granulose or shagreened, and in part densely punctulate, opaque. Gaster densely punctulate but shining. Dorsum of head with fine, irregular, more or less longitudinal rugae; disc of pronotum with similar rugae which are more irregular and somewhat reticulate.

Head and body shape, and arrangement of the large specialized hairs as shown. Note the projecting and angulate occipital lobes. Mandibles finely and densely punctate, shining, with the external border practically straight; inner border with 9-11 teeth; basal tooth offset and small. Thoracic dorsum divided into a large, rounded promesonotunl and a much smaller and narrower epinotum, separated from each other by a shallow metanotal groove. Epinotal armature consisting of a pair of broad, sub diaphanous, thin plates containing the obtusely dentate epinotal spine and the not receding infradental lamella. Peticolar node cuboidal, as long as broad, anteriorly rounded, posteriorly sharply marginate and weakly bidentate, excised beneath the dentition; subpetiolar tooth distinct. Postpetiole reniform, transverse, twice as broad as petiolar node, with a postero-median and posterolateral impressions. Tergum and sternum I of gaster anteriorly marginate and carinulate; sternum I without a sagittal keel.

Large specialized hairs present in full complement, 18 (3 rows: 8-4-6) on head, 3 pairs on thorax, 1 pair on petiole, 2 pairs on postpetiole, 4 irregular longitudinal rows of 4 hairs each (lateral row often with only 3 hairs) on tergum I of gaster. These hairs have a thick, somewhat flattened and spoon-shaped head and are strongly bent at apex (subapressed) except on gaster where they are suberect. Leading edge of scapes fringed with spatulate hairs which are strongly curved basad; dorsal scape surface with similar subappressed spatulate ground hairs. Ground pilosity well-formed and conspicuous on head, pronotum, mesonotum, both nodes and legs, consisting of relatively large, abundant, subappressed scalelike hairs, which are almost half as long as the specialized hairs. Widely scattered and inconspicuous appressed smaller hairs on gaster.

Queen
(paratype). - Total length 5.6 mm; head length 1.12 mm; head width 1.17 mm; thorax length 1.55 mm. Cephalic index 105. Essentially the same as worker, but of darker color throughout, with large eyes (maximum diameter 0.21 mm), small ocelli, well-developed pterothorax. Pronotum with a pair of specialized hairs on each side; scutum with a median sagittal hairsless groove, flanked on each side by a series of narrowly spatulate, suberect hairs; a specialized hair on each of the paraptera; scutellum with a pair of specialized hairs, posteriorly prominent, feebly bilobed, overhanging the epinotum which practically lacks a basal face. Petiolar node with the same posteriorly carinate border which is excavate beneath. Specialized hairs on tergum I of gaster thinner, erect, more numerous, arranged in 4 irregular longitudinal rows. Wings unknown.

Type Material
Longino (2013) - Holotype worker: Brazil, São Paulo: Caraguatatuba, State Forest Reserve, 40 m elevation, 7-14 Jul 1962, nesting in Bromeliaceous plant growing on a fallen tree trunk in the woods (K. Lenko, No. 2183) ? "Departamento de Zoologia, São Paulo"] (not examined). Paratypes: workers and queen, same data as holotype MZSP; Ilha de Vitória, 25km off the shore of Ubatuba, 26 Mar 1964, nesting in a bromeliaceous plant growing on the soil (K. Lenko, No. 4031).