Malaconothrus Berlese, 1904

Colloff, Matthew J. & Cameron, Stephen L., 2013, A phylogenetic analysis and taxonomic revision of the oribatid mite family Malaconothridae (Acari: Oribatida), with new species of Tyrphonothrus and Malaconothrus from Australia, Zootaxa 3681 (4), pp. 301-346 : 306-307

Malaconothrus Berlese, 1904

Lohmannia (Malaconothrus) Berlese, 1904

Type species: Nothrus monodactylus Michael, 1888 , designated by Sellnick, 1928, p. 18.

Trimalaconothrus Berlese, 1916 , p. 336, syn. nov.

Type species: Malaconothrus (Trimalaconothrus) indusiatus Berlese, 1916 , by original designation.

Zeanothrus Hammer, 1966 , p. 20; syn. Subías, 2004, p. 61.

Type species: Zeanothrus elegans Hammer, 1966 , p. 20, Fig. 24, by original designation.

Cristonothrus Subías, 2004, p. 7. syn. nov.

Type species: Malaconothrus pauciareolatus Subías & Sarkar, 1982 , by original designation.

Definition and diagnosis. Malaconothrid mites with the following combination of characters. Carina narrow, straight or curved, extending as far as seta ro, occasionally incurved posterior of ro, giving anterior prodorsum a truncated appearance; never enclosing seta le. Seta in long, typically 2–3 × longer than seta ex, or occasionally both in and ex 1 short, sub-equal. Caudal region of hysterosoma typically U-shaped, as broad or narrower than anterior region; notogastral margins parallel. With centrodorsal ridges and M-shaped posterior ridges, or ridges secondarily lost, as indicated by vestigial structures. Anteriolateral margin of epimeral plates I rounded or with a pronounced projecting spur. Apodeme IV narrow, bow-shaped. Genital setae 4–9 pairs. Tarsi, particularly Tarsus I, short, broad, never elongated, typically no more than 1.5–2 × longer than maximum width. Notogastral setae sub-equal in length, or with the centrodorsal series (particularly c 1, d 1 and e 1) longer than others, or with e 2 and h 2, and occasionally h 1, longer than others. Body setae typically smooth, occasionally barbed. Leg setae smooth. Pre-tarsi monodactylous or tridactylous.

Tyrphonothrus can be separated from Malaconothrus by two consistent synapomorphies: an elongated tarsus I (compare Figs. 6 a and 14a) and the incurved, S-shaped prodorsal carinae (compare Figs. 3 a and 12a).

Remarks. Because all of the species of Malaconothrus fall into one large clade and it is not possible to distinguish discrete subgenera, it is implicit that the genera and subgenera in the synonymic list above are synonyms at the subgenus level, i.e of Malaconothrus (Malaconothrus) .

Cristonothrus Subías, 2004 was proposed as a subgenus of Malaconothrus . It might be considered that its synonymy with Malaconothrus might be weakened because the type species, M. pauciareolatus was not included in the phylogenetic analysis (15 characters could not be coded). However, the reasons for the synonymy are: 1) Cristonothrus was created based on only one character, the notogastral ridges, and this is not a synapomorphy within Malaconothrus ; 2) Cristonothrus does not form a discrete phylogenetic unit. Even though all except one species are contained within one of the two major clades in Malaconothrus ( Fig. 2 ), that clade also contains species formerly in Malaconothrus (Malaconothrus) , Trimalaconothrus (Trimalaconothrus) and Trimalaconothrus (Tyrphonothrus) .

Figures

FIGURE 2. Cladogram of selected Malaconothridae showing two major clades, Tyrphonothrus and Malaconothrus. Designations of species to nominate subgenera, Trimalaconothrus (Tyrphonothrus) and Malaconothrus (Cristonothrus) follows Subías (2004). Bold type = species with complete notogastral ridges; * = species with partial ridges; M (M), M (C) = monodactylous; T (T), T (Ty) = tridactylous. Percentage probabilities of each node are indicated if other than 100.

FIGURE 3. Tyrphonothrus gnammaensis sp. nov., holotype female; a) dorsal; b) ventral.

FIGURE 6. Tyrphonothrus gringai sp. nov., holotype female, left legs, antiaxial view; a) Leg I; b) Leg II; c) Leg III; d) Leg IV.