MACROXENINAE Condé, 2008

Duy-Jacquemin, Monique Nguyen, 2009, Revision of the genera of Polyxenidae bearing pseudoarticulated gnathochilarial sensilla (Diplopoda, Polyxenida, Polyxenidae), with the description of two new species, Zoosystema 31 (4), pp. 829-848 : 830-831

Subfamily MACROXENINAE Condé, 2008

REMARKS

Silvestri (1948) characterized three genera of Polyxenidae bearing pseudoarticulated gnathochilarial sensilla: Chilexenus , Macroxenodes and Macroxenus . He distinguished Chilexenus as provided with “3 sensillis bacilliformibus” on antennal article VI, as opposed to more than three in Macroxenodes and Macroxenus . Silvestri’s distinction between Macroxenodes and Macroxenus was based on the length and structure of the hooked trichomes of the caudal penicillus – characters that are no longer valid. Because of this and the addition of a fourth genus, Afraustraloxenodes , bearing pseudoarticulated gnathochilarial sensilla, a new identification key is necessary. Recently these four genera have been combined in a subfamily Macroxeninae Condé, 2008 (Condé & Nguyen Duy-Jacquemin 2008).

Other differences between the four genera

Only in Macroxenus are all the trichomes of the tergites oriented towards the telson ( Fig.11B ). In Macroxenus , the ratio length/diameter of tergal trichomes is larger than in Macroxenodes and Afraustraloxenodes . In the only examined syntype of Chilexenus , the length of trichomes seems similar to that of Macroxenus .

KEY TO THE GENERA OF THE SUBFAMILY MACROXENINAE CONDÉ, 2008

1. Spine on metatarsus (tarsus II) ................................................................................... 2

— Setiform sensilla on metatarsus ................................................................................... 3

2. Short distance between oval lateral tufts of trichomes. Three sensilla basiconica on antennal article VI ...................................................................................................... Chilexenus — Large distance between oval lateral tufts of trichomes. More than three sensilla .............

................................................................................................................... Macroxenus

3. Antennal, prefemoral, femoral and tibial setiform sensilla ending in three or four spines ................................................................................................................ Macroxenodes

— Antennal, prefemoral, femoral and tibial setiform sensilla ending in a single spine ........ ......................................................................................................... Afraustraloxenodes

Figures

FIG. 11. — Insertions of trichomes on tergite VIII in adult females: A, Chilexenus rosendinus (Silvestri,1903),lectotype; B, Macroxenus rubromarginatus (Lucas, 1846), from Ifrane; C, Macroxenodes meinerti (Silvestri, 1898), cotype; D, Afraustraloxenodes namibiensis Nguyen Duy-Jacquemin, 2003, paratype. Scale bars: 50 μm.