Kempfidris

The little that is known about the biology of this monotypic genus is provided on the species page of Kempfidris inusualis.

Identification
A monotypic genus.

Fernández et al. (2014) - The strongly reduced eyes and the long diastema between the three apical teeth and the basal tooth do not appear to be common in myrmicines. Kempfidris is reminiscent of Cryptomyrmex regarding the mandibular configuration (four teeth with a diastema), clypeal structure (elevated median area), single median seta along the anterior clypeal margin, and reduced number (2) of maxillary palp segments. However, Cryptomyrmex has a different antennal structure (12 segments, the last two forming a club), modified hairs along the mandibular masticatory margin and subcutaneous ommatidia. Reduced eyes can be found in the African fossulatum-group of Monomorium (Bolton 1987), as well as in Carebarella.

The most outstanding feature of Kempfidris is the series of minute, hair-bearing tubercles or cylindrical pegs on the abdominal apex. Most are concentrated on the anteromedian portion of the pygidium and some on the posteromedian portion of abdominal tergite VI, a position that would coincide with the position of the pygidial gland, which opens between abdominal tergites VI and VII (Billen 2009). The structure of the micropegs with their associated hairs also hints at some sort of glandular function, or possibly a mechano-reception function during stinging, but a more convincing explanation will only be possible after a histological study. Whatever the function of these tubercles, they appear to be an autapomorphic structure, absent in other Myrmicinae and probably in other ants as well.

Despite its broad distribution, specimens of K. inusualis are relatively uniform in size and general aspect. As already mentioned by Fernández (2007), the main differences regarding geographic variation involve slightly distinct propodeal shapes, such as a shorter dorsal face in the Ecuadorian specimens. Specimens from Rondônia, Brazil, differ from other conspecific workers by their darker color (almost black) and more prominent propodeal crests that form small denticles. Given the similarity among the samples examined, we decided to consider these morphological differences as intraspecific variation.

Castes
Known only from the worker caste.

Nomenclature

 *  KEMPFIDRIS [Myrmicinae]
 * Kempfidris Fernández, Feitosa & Lattke, 2014: 3. Type-species: Monomorium inusuale, by original designation.

Worker
Antenna 12-segmented, with a well-defined 3-segmented club. Eye reduced to almost indistinct ommatidia, placed just anteriorad of head midlength. Frontal carinae and antennal scrobes absent. Mandible with four teeth: three apical teeth separated from isolated basal tooth by large diastema. Palpal formula 2,1. Clypeus projected anteromedially to form truncate lobe, lobe laterally bluntly angular and medially weakly concave, with distinct median seta and several surrounding setae. Median lobe of clypeus strongly bicarinate, carinae defining elevated area that converges posteriorly to form narrow strip between frontal lobes. Pronotum with anterolateral crest that extends dorsally, delimiting narrow anterior portion of pronotum. Metanotal groove very deep, well-marked. Bulla of metapleural gland large. Propodeum unarmed, declivity surrounded dorsolaterally by a crest, higher laterally than dorsally and joining the small metapleural lobe. Posteromedian portion of abdominal tergum VI and anteromedian portion of abdominal tergum VII with several minute, cylindrical micro-pegs, each bearing a hair on apex, though apparently broken in some.

Etymology
It is with great pleasure that we dedicate this new genus to Father Walter W. Kempf (1920–1976) for his brilliant, but somewhat short career in ant taxonomy, with special reference to the Neotropical fauna. Besides the many monographs and descriptions of new taxa, Kempf provided the first catalog of Neotropical ants (Kempf 1972), an obligate reference (until recently) for generations of myrmecologists.