Onchodellus Berlese, 1904

MAŠÁN, PETER & HALLIDAY, BRUCE, 2014, Review of the mite family Pachylaelapidae (Acari: Mesostigmata), Zootaxa 3776 (1), pp. 1-66 : 11

Genus Onchodellus Berlese, 1904

Pachylaelaps (Onchodellus) Berlese, 1904: 452 .

Type species Pachylaelaps (Onchodellus) reticulatus Berlese, 1904 , by monotypy.

Berlese’s (1904) attempt to divide the genus Pachylaelaps into subgenera Pachylaelaps s. str. and Onchodellus was not generally accepted. Koroleva (1977b) and Karg (1993) synonymised Onchodellus with Pachylaelaps . Later, the separate taxonomic status of Onchodellus was accepted by Evans & Till (1979) and Moraza & Johnston (1990), because the original Pachylaelaps exhibits two main morphological patterns previously noted by Koroleva (1977b) and Evans & Till (1979) in their identification keys: (1) species with a slender hypostome and elongated corniculi, a sperm access system associated with coxae IV, sexual dimorphism of the palp tibia (male with palp tibial outgrowths), two spur-like distal setae on female tarsus II, and 13 setae on genu I; and (2) species with a wider and shorter hypostome and normal horn-like corniculi, a sperm access system associated with coxae III, sexual dimorphism of palp tibia not developed, one spur-like distal setae on female tarsus II, and 12 setae on genu I.

The genus Onchodellus is now based especially on the following character states: (1) spermathecal tubes of sperm access system strongly elongated, fine, and associated with coxae III, (2) clunal setae J5 needle-like and similar in size to the other dorsal shield setae, (3) gland opening gdZ1 mostly not modified and circular (if slit-like, then antiaxial to alignment Z1–Z2), (4) female tarsus II with one spur-like distal seta, and genu I with 12 pairs of setae. It is by far the largest genus of Pachylaelapidae , with up to 80 species distributed mainly in Europe, Asia and Africa.