Belongs within: Eleutherengonides.
Stigmaeus is a genus of predatory mites with ten to sixteen dorsal shields on the idiosoma, and four pairs of setae on the prodorsal shield (Khanjani & Ueckermann 2002).
Characters (from Khanjani & Ueckermann 2002): Idiosoma with 10–16 dorsal shields, dimpled or reticulated in most species; prodorsum with four pairs of setae on single large or on a large median and a pair of lateral shields; opisthosomal shielding consisting of an unpaired median shield bearing two or three pairs of setae and unpaired or paired suranal shield and three or six pairs of smaller shields (humerals, marginal, median zonals, lateral zonals and intercalaries) surrounding median shield. Median shield distinct, indistinct or absent. Dorsum with 13–14 pairs of setae.
<==Stigmaeus Koch 1836KU02
|--*S. cruentus Koch 1836KU02
|--S. africanusE-KO07
|--S. alvandis Khanjani & Ueckermann 2002KU02
|--S. antrodes Berlese 1910SB63 [incl. S. antrodes var. reticulatus Halb. 1923G44]
|--S. bdelloidesSS55
|--S. bicolor Canestrini & Fanzago 1876CF77
|--S. brevisetis Wood 1967SL71
|--S. campbellensis Wood 1970SL71
|--S. confusus Wood 1967SL71
|--S. coprosmae Wood 1967SL71
|--S. elongatus Berlese 1886 [incl. S. luteus Summers 1962]KU02
|--S. eutrichus Berlese 1910SB63
|--S. fissuricola Halbert 1920 [=S. rhodomelas var. fissuricola]S76
|--S. loadmani Wood 1967SL72
|--S. longisetis wood 1967SL71
|--S. purpurescensNK94
|--S. raneyiNK94
|--S. rhodomelas Berl. 1910G44
|--S. rotundus Wood 1967SL71
|--S. rupicola Wood 1967SL71
|--S. sinaiWL09
|--S. spagnetiWHE88
|--S. summersi Wood 1967SL71
|--S. unicus Kuznetzov 1977KU02
`--S. zaheriE-KO07
*Type species of generic name indicated
References
[CF77] Canestrini, G., & F. Fanzago. 1877. Intorno agli Acari Italiani. Atti del Reale Istituto Veneto di Scienze, Lettere ed Arti, Serie 5, 4: 69–208, pls 2–7.
[E-KO07] El-Kammah, K. M., & L. M. I. Oyoun. 2007. Taxonomic records of mite species associated with animal and poultry farms in the Nile delta, vally and N. Sinai Egypt. In: Morales-Malacara, J. B., V. M. Behan-Pelletier, E. Ueckermann, T. M. Pérez, E. G. Estrada-Venegas & M. Badii (eds) Acarology XI: Proceedings of the International Congress pp. 223–232. Instituto de Biología and Faculdad de Ciencias, Universidad Nacional Autónoma de México, Sociedad Latinoamericana de Acarología: México.
[G44] Grandjean, F. 1944. Observations sur les acariens de la famille des Stigmaeidae. Archives des Sciences Physiques et Naturelles, 5me Période 26: 103–131.
[KU02] Khanjani, M., & E. A. Ueckermann. 2002. The stigmaeid mites of Iran (Acari: Stigmaeidae). International Journal of Acarology 28 (4): 317–339.
[NK94] Norton, R. A., & J. B. Kethley. 1994. Ecdysial cleavage lines of acariform mites (Arachnida, Acari). Zoologica Scripta 23 (3): 175–191.
[SB63] Schweizer, J., & C. Bader. 1963. Die Landmilben der Schweiz (Mittelland, Jura und Alpen): Trombidiformes Reuter, mit 217 Arten und Unterarten und 193 Originalzeichnungen. Denkschriften der Schweizerischen Naturforschenden Gesellschaft [Mémoires de la Société Helvétique des Sciences Naturelles] 84 (2): i–vi, 209–378.
[SL71] Spain, A. V., & M. Luxton. 1971. Catalog and bibliography of the Acari of the New Zealand subregion. Pacific Insects Monograph 25: 179–226.
[SS55] Summers, F. M., & E. I. Schlinger. 1955. Mites of the family Caligonellidae (Acarina). Hilgardia 23 (12): 539–561.
[WHE88] Walter, D. E., H. W. Hunt & E. T. Elliott. 1988. Guilds or functional groups? An analysis of predatory arthropods from a shortgrass steppe soil. Pedobiologia 31: 247–260.
[WL09] Walter, D. E., E. E. Lindquist, I. M. Smith, D. R. Cook & G. W. Krantz. 2009. Order Trombidiformes. In: Krantz, G. W., & D. E. Walter (eds) A Manual of Acarology 3rd ed. pp. 233–420. Texas Tech University Press.