Acronothrus, Berlese, 1917

van der Hammen, L., 1959, Berlese's Primitive Oribatid Mites, Zoologische Verhandelingen 40, pp. 1-93 : 67-68

Acronothrus Berlese, 1916

Acronothrus Berlese, 1916, p. 65.

Berlese created Acronothrus (as subgenus of Nothrus ) in 1916, with Nothrus cophinarius Michael , 1908 (from New Zealand) as type. I do not know if Berlese studied the type-specimen; he did not give a generic diagnosis, but only mentioned Neoliodes americanus Berlese , 1901 (from South America) as other representative of the genus. Later (Berlese, 1916a) he added A. alluaudi Berlese (East Africa) and A. rothschildi Berlese (Ethiopia). Although Berlese (1916) did not mention Nothrus camelus Berlese (1910b), this species from Noumea certainly belongs to the genus. Nothrus unguifera Michael , 1908 (from New Zealand), described as closely related to N. cophinarius , is possibly only the other sex of the last-mentioned species. The genus is best known by the description of Acronothrus nukuhivae (with var. hivaoae ) Jacot (1935, p. 218, fig. ic-g), a species from the Marquesas islands. According to Jacot, this species resembles unguifera ; it appears that the genus Acronothrus is related to Camisia .

Oudemans (1937, p. 2560, fig. 1097bis) discovered an interesting publication by Cambridge (1875), which escaped the notice of most authors. It appears that Cambridge described a new species of mite ( Westwoodia obtecta ) as a harvestman (new family: Crotonoides ); because the name Westwoodia had already been used for different animals, Thorell (1876, p. 454) altered the generic name into Crotonia . As Willmann wrote to Oudemans (l.c.), Crotonia obtecta (Cambridge) is related to Nothrus cophinarius , and especially to N. unguifera .

I do not know whether the type of obtecta is still in existence, but probably Acronothrus Berlese (1916) and Crotonia Thorell (1876) are synonyms, just as the family names Camisiidae Oudemans (1900) and Crotoniidae Cambridge (1875). It will, however, be better to have the names Crotonia and Crotoniidae suppressed for purposes of synonymy.

As far as known the genus Acronothrus has a remarkable distribution: New Zealand, Noumea, Marquesas islands, East Africa, and South America 1).

1) Womersley (1957, p. 22, fig. 1) recently described Acronothrus ramus , a fossil species from Australian resin (probably Upper Tertiary); it is related to A. cophinarius Michael .