Myrmozercon Berlese

Joharchi, Omid & Moradi, Maryam, 2013, Review of the genus Myrmozercon Berlese (Acari: Laelapidae), with description of two new species from Iran, Zootaxa 3686 (2), pp. 244-254 : 245

Genus Myrmozercon Berlese

Myrmozercon Berlese, 1902: 699 . Type species Myrmozercon brevipes Berlese, 1902 , by monotypy.

Myrmonyssus Berlese, 1903: 16 . Type species Myrmonyssus diplogenius Berlese, 1903 , designated by Berlese, 1904 (synonymy by Rosario & Hunter, 1988).

Myrmonyssus (Laelaspulus) Berlese, 1904: 437 . Type species Myrmozercon acuminatus Berlese, 1903 , by original designation (synonymy by Shaw & Seeman, 2009).

Parabisternalis Ueckermann & Loots, 1995: 35 . Type species Parabisternalis yemeni Ueckermann & Loots, 1995 , by original designation (synonymy by Shaw & Seeman, 2009).

Notes on the genus. The diagnosis of Myrmozercon used here is based on that of Shaw & Seeman (2009). Most species of Myrmozercon , including the type species M. brevipes and the new species M. crinitus , show moderate to strong hypertrichy on the dorsal shield. However, M. karajensis Joharchi et al., 2011 (approximately 33 pairs), Myrmozercon cyrusi Ghafarian & Joharchi, 2013 (33 pairs) and the new species Myrmozercon michaeli (39 pairs), have a reduced dorsal chaetotaxy. All species appear to have asymmetrical and unpaired setae on the dorsal shield, which makes it difficult to recognise their homology, except for M. cyrusi Ghafarian & Joharchi, 2013 and the new species M. michaeli . In most species the dorsal shield is reduced or truncated posteriorly to expose a strip of unsclerotised opisthonotal skin, but this is not true in every species. Species of Myrmozercon also vary in the presence or absence of metasternal setae st4, and the extent to which the sternal shield is fused with the endopodal plates. The sternal shield of M. michaeli is similar to that of many free-living Mesostigmata , with three pairs of setae and two pairs of lyrifissures, separate endopodal plates between coxae III and IV, and separate metasternal setae in the soft skin. The leg chaetotaxy of Myrmozercon species is also variable, and does not provide diagnostic characters that define the genus ( Shaw & Seeman, 2009). The new species M. michaeli adds variation to the denticles in the hypostomal groove, by having only seven rows of denticles, where all other species have more than seven rows of denticles. Shaw & Seeman (2009) described a swelling on the dorso-distal edge of the palp trochanter in several species. This structure is not present in M. karajensis , and the new species M. michaeli has a low swelling on the dorsodistal edge of the palp femur. This instability in morphology, and the edentate chelicerae and short peritremes of Myrmozercon , suggest that Myrmozeron is parasitic on its ant hosts, and not simply a commensal in its host's nests, but this has not been established experimentally. The specimens examined here were found clinging to the abdomen and head of their host ants.