Quartusmichaelia dimixsetosa ( McDaniel, 1980 ), 2025

Quartusmichaelia dimixsetosa ( McDaniel, 1980) comb. nov.

( Figs. 36A–D, 37A–E, 38A–E, 38G and 39A–F)

Bimichaelia dimixsetosa McDaniel, 1980: 181 View in CoL , figs. 7–12; holotype from South Dakota .

Laminamichaelia dimixsetosa View in CoL .— Uusitalo 2010: 69.

Description. Dorsum (n= 2 females, Figs. 36A, B, 38A–E, 38G, 39A). Length 400–450 µm; cells of primary pattern formed by large roundish to polygonal lamellae; intraspecific variation in setal lengths; prodorsum: soft integument with 12 to 14 setae; crista with central area of polygons flanked by two strips; sensilla ve distally with 4–5 branches and basally barbed; usually 2 (rarely 4) setae in short, plumate; lamellae in rows between ve and in, polygonal lamellar fields posterior to setae in.

Venter ( Figs. 36C, D, 39B). Setae sparsely ciliated; sclerotised genital valves each with 6–8 genital setae; anal setae 4–5 per valve.

Gnathosoma ( Figs. 37E, 39B). Chelicerae straight; subcapitulum with two pairs of setae or slightly neotrichous; palpal solenidion inserted on a small protrusion, slightly constricted medially and in contact with one eupathidion, the other eupathidion being free.

Legs ( Figs. 37A–D, 39C–F). Solenidial formula for tarsi, tibiae, genua and femora on legs I, II, III and IV, respectively: 2B-2B-0-0, 2\3B1P-2B1P-2B-1B, 4P-1B2P-1P-1P, 2P-1B1P-0-0, solenidion ω1 twisted, baculiform solenidia on tibiae obliquely parallel and some distance apart, famulus I distal, placed abaxially.

Tritonymph (n=3). Length 340–390 µm, cleavage line, one pair of in -setae, three pairs of genital papillae, 6 genital setae per valve, 4 anal setae per valve, solenidial formula same as in adult stage.

Material examined. The holotype female from South Dakota, Davison Co., is at least temporarily lost; however, there are five specimens collected by Eric G. Bolen and determined by B. McDaniel as Bimichaelia dimixsetosa from Texas, USA, (ca. 1500 km S of the type locality), deposited at the Texas A&M University, with collection numbers TAMU-ENTO X164…: 1 female from roadside, spot where highway US 87 crosses the railway track that parallels highway 1881, Swisher Co., 22 July 1979, slide # X1645512; 1 deutonymph from loam soil, grazed shin oak ( Quercus havardii ), 10 miles N Shamrock, Rt. 83, junction FM (Farm to Market road) 1906, Wheeler Co., 17 August 1979, slide # X1645052; 1 specimen from rail road siding rocks + shrubs, Bad River Road, Grasshopper stage, Stanley Co., 2 July 1980, slide # X1647600; 1 tritonymph from light soils, mesquite grass ( Hilaria belangeri ), 1 mile S Woodsboro, Refugio Co., 14 November 1977, slide # X1645426; 1 deutonymph as Bimichaelia from light soils, mesquite grass ( Hilaria belangeri ), 1 mile S Woodsboro, Refugio Co., Texas, 14 November 1977, slide # X1645544.

2 females and 3 tritonymphs as Bimichaelia sp. from Utah juniper ( Juniperus osteosperma ) detritus, Providence Canyon, Cache Co., Utah, USA, 30 April 1974, G.F. Knowlton, deposited at the Acarology Laboratory, Ohio State University, coll. No. AL5335, female on slide NA20 is used for drawings ( NA 21 is female, NA26, NA27 and NA 28 are tritonymphs).

Differential diagnosis. Q. dimixsetosa is distinguished from Q. setigera , Q. lanceolata and Q. plumata by having 4–5 distal branches on sensilla ve (vs. sensilla ve simple, branched and with a distal scale bunch, respectively) and having ciliate dorsal setae (versus lanceolate). In comparison to Q. shibai , which shares ciliated dorsal setae, the sensilla ve of Q. dimixsetosa are branched and there are two baculiform solenidia on tarsi II (versus densely ciliated from top to bottom and only one baculiform solenidion on tarsi II). Laminamichaelia knowltoni , with the prodorsum confusingly similar looking to that of Quartusmichaelia dimixsetosa ( Fig. 38F vs. Figs. 38E, G), belongs to Laminamichaelia by having 3 baculiform solenidia on tarsi I, two pairs of setae in, and the tibial baculiform solenidia are aligned one after another.

Remarks. The original picture of Bimichaelia dimixsetosa now placed in Quartusmichaelia ( Fig. 39A), based on the holotype and 3 paratypes from South Dakota ( McDaniel 1980), showed the elongated setae were located mainly on the caudal segments excepting a few on segments D and E. The museum for deposition of the type material was not indicated and the material has not been heard of since. Dorsal setae are of various lengths also in the 5 specimens of the Utahan material, collected by G.F. Knowlton and examined by me using phase-contrast microscopy. The elongated setae are perhaps not as striking as in the original picture ( Fig. 39A), and their numbers seem to vary intraspecifically, from one to several per specimen ( Figs 38A–D). However, absence of solenidia and the famulus from legs, and by depicting the ventral integument by uniform, long and parallel lines, suggest some inaccuracy in the original illustrative technique ( Figs. 39A–F).

The subspecies Bimichaelia dimixsetosa texana was established for specimens without the elongated dorsal setae by McDaniel & Bolen (1983: 816, no figures). The type specimen from Cottle County, southern High Plains of Texas and 56 paratypes from 8 counties were collected in 1977–1980. Unfortunately, this material is also at least temporarily lost. ”The material will be deposited with National Museum of Natural History, Washington, D.C.” according to the original article, but it is not in the museum’s database (Dr. Debra Creel, in litt) .

McDaniel (1980) and McDaniel & Bolen (1983) described 4 new species and 1 subspecies of Alycidae . Bolen’s role at that time was as collector of soil samples in the field, from which he extracted the microfauna and sent the preserved material to McDaniel, who did all the diagnostic work and continued handling (Dr. Eric G. Bolen, in litt.), and he has no knowledge of the deposition processes.

There is, however, material of the species from Texas, determined by McDaniel, and obviously, the species has a wide distribution in arid environments (see Material examined). McDaniel’s collection includes 16 specimens from the 8 counties, labelled as B. dimixsetosa (11 specimens) and B. dimixsetosa texana (s) (5 specimens) either in pencil or in ink, and with a handwritten note: “ Bimichaelia dimixsetosa sub species texanas. Does not have large setae on dorsal region as does South Dakota specimens. Has all other structures of B. dimixsetosa ”. However, the last statement proved to be imperfect .

The five slides labelled as Bimichaelia dimixsetosa texana (s) proved to represent three different species: Laminamichaelia knowltoni sp. nov. (3 specimens, one of them was collected from Cottle County, the same county as for the holotype of the subspecies), Laminamichaelia arbusculosa (Grandjean) (1 specimen) and Quartusmichaelia shibai (Uusitalo et al.) (1 specimen).All those species have filamentous sensilla ve densely ciliated by cilia of various lengths. The differences become obvious if we look at the numbers of setae on in -area, numbers and positions of baculiform solenidia and positions of famulus I, as indicated in the diagnoses of the species, for which character states are not always easy to see and interpret, especially from juvenile stages on poor slides.

By looking at the dorsal setae, McDaniel recognized the difference between B. dimixsetosa and other specimens in the material at the adult level but overlooked solenidiotaxy, and he failed to notice that there were actually four species with the dorsal setae of similar size: Laminamichaelia arbusculosa , a new species ( L. knowltoni , see below), Quartusmichaelia shibai , and possibly Q. dimixsetosa with none elongated dorsal setae. Obviously, McDaniel’s establishment of a new subspecies to the Quartusmichaelia is unfounded considering ambiguity of characters used and the multiple taxa identified as this species, especially considering that it remains unclear, which one of the four species was chosen for the holotype of texana by him. The new species is conspecific with the specimens collected by G.F. Knowlton from Utah in 1974 and named below as Laminamichaelia knowltoni sp. nov. to avoid any future confusion with Quartusmichaelia dimixsetosa .

Genus Laminamichaelia Uusitalo, 2010

Type species: Bimichaelia arbusculosa Grandjean, 1942 from France; by original designation .

Differential diagnosis. In Laminamichaelia and Quartusmichaelia , multiciliate setae are surrounded by polygonal or roundish loops, formed by a primary pattern of large lamellae, and the secondary pattern is formed by transversely packed small lamellae in even rows inside loops ( Figs. 51D, E, 53A, C, E, G, I, K). Other diagnostic features of Laminamichaelia are: both in -area and soft prodorsum are neotrichous and there are usually three baculiform solenidia on tarsi I ( Figs. 40A, 41B, 42A, 43B 53J, L), in comparison to Quartusmichaelia where extra setae, if any, are only on soft prodorsum (only one pair of setae in) and one of the two baculiform solenidia on tarsus I is hook-like or S-shaped ( Figs. 29A, 30A, 31A, 32A, 33A, 34A, 35A, D, 36A, 37A, 53B, D). In Minimamichaelia , the reticular pattern is absent, and small to middle-sized lamellae are arranged transversely in undulating rows and lines, middle-sized lamellae being in clumps in culmination points; and prodorsum is holotrichous ( Figs. 27A, 51C, 52E–G, 55A). The primary pattern of Bimichaelia forms roundish to subpolygonal loops of large lamellae; tiny ridges inside loops are granular ( Figs. 23A, 25A, B, 51A, 52 A-C); and the prodorsum is holotrichous. In Laminamichaelia the dorsal setae are easily discernible because of several elongated cilia per seta ( Figs. 40B, 42B, 44B, 53I), whereas all dorsal setae of Bimichaelia have less than ten, mainly short barbs basally, which are difficult to discern against the intricate cuticular pattern ( Fig. 52A). The integumental ridges are parallel and without granulae and laminae in Glabromichaelia ( Figs. 19B–E, 51B).