Alienocacculus Kanaar, 2008

Lackner, Tomáš, 2010, Review of the Palaearctic genera of Saprininae (Coleoptera: Histeridae), Acta Entomologica Musei Nationalis Pragae (suppl.) 50, pp. 1-254 : 65

Alienocacculus Kanaar, 2008

Alienocacculus Kanaar, 2008: 187 . Type species: Hypocacculus (Nessus) neftensis Olexa, 1984 , original designation.

Diagnosis. Antennal scape strongly dilated and thickened, resembling a trapezoid, furnished with long strongly sclerotized setae; both mandibles with large sub-apical tooth; penultimate labial palpomere with single long seta; frontal stria interrupted medially; frontal disc ruguloselacunose; head rather small; eyes flattened but visible from above; pronotal foveae absent; pronotal hypomeron and elytral epipleuron setose; pre-apical foveae large, deep, situated antero-laterally from lateral prosternal striae; lateral parts of pleura and sterna setose; protibial spur large, stout.

Differential diagnosis. Alienocacculus resembles most closely the subgenus Nessus of the genus Hypocacculus (the type species of Alienocacculus has originally been described as Nessus ), but differs chiefly by the setose elytral epipleuron, the size and unusual position of the pre-apical foveae and the interrupted frontal stria. A setose elytral epipleuron is found in several other Palaearctic genera of the subfamily: Xenophilothis , Turanostyphrus , Xenonychus and Ctenophilothis . From these genera, Alienocacculus chiefly differs by the following characters: from Xenophilothis by the differently shaped protibia, differently shaped and asetose prosternal process and the presence of pre-apical foveae (absent in Xenophilothis ); from Turanostyphrus by the differently shaped tibiae and prosternal process and the presence of pre-apical foveae (absent in Turanostyphrus ); from Xenonychus by the different elytral striation, structure of the frontal disc (almost completely smooth in Xenonychus , rugulose-lacunose in Alienocacculus ) and the medially interrupted frontal stria (complete in Xenonychus ); and from Ctenophilothis by the differently shaped protibia, less convex ventral surface of the body, the presence of the antennal groove (absent in Ctenophilothis ), different elytral striation, rugulose-lacunose frontal disc (smooth in Ctenophilothis ) and the large and globular sub-apical tooth on the left mandible (minute in Ctenophilothis ).

Biology. Although the biology of this taxon is poorly documented, one species, A. neftensis (Olexa, 1984) was collected in sand dunes near the Tunisian city of Nefta and A. vanharteni was collected at light in a desert area ( KANAAR 2008; Pavlíček, pers. comm. 2007). The morphological characteristics of this genus (underside of body with dense vestiture, small head and flattened eyes) and the collecting sites suggest that it belongs to the group of specialized psammophilous Saprininae mentioned by OLEXA (1984) and KANAAR (2008).

Distribution. This recently erected genus occurs in desert regions and is known from the Nefta oasis in Tunisia and from the Negev Desert in southern Israel and the environs of Dubai in the United Arab Emirates.

Species examined. Alienocacculus neftensis (Olexa, 1984) and A. vanharteni Kanaar, 2008 .

Discussion. This genus is characerized by several putative synapomorphies: strongly dilated antennal scape resembling a trapezoid, large sub-apical tooth of mandibles and penultimate labial palpomere with single long seta. Other characters including rugulose frons, setose elytral epipleuron and small flattened eyes are most likely homoplasies and do not constitute characters useful for a phylogenetic delineation of this taxon. The monophyly of this taxon should be tested in the future, especially with respect to the presumably related taxa like Hypocacculus (Nessus) and Dahlgrenius .