Oribatella reticulatoides Hammer, 1955

Behan-Pelletier, V. M., 2011, Oribatella (Acari, Oribatida, Oribatellidae) of eastern North America, Zootaxa 2973 (1), pp. 1-56 : 45-47

Oribatella reticulatoides Hammer, 1955

Oribatella reticulatoides Hammer, 1955, p. 25

Oribatella reticuloides Hammer, 1955 (lapsus) in Marshall et al. 1987

( Fig. 23D)

Material examined. Paratype male, U.S.A., Alaska, AIP Lab. In 83 Gen. hosp. (?) 6.viii.1948 (Sailer). This specimen was identified by M. Hammer and formed part of her study on Alaskan Oribatida ( Hammer 1955) ; it was remounted from a dried Hoyer’s slide by R.A. Norton, 16.xii.1983 and presently is in the RNC. Also: Canada, Ontario, Black Sturgeon Lake, 49°19’N 88°49.5W, 25.viii.1972 ( EEL) 1 from burrow litter under cedar tree base; New Brunswick, Kouchibouguac National Park, Kelly’s Beach, 3.viii.1977 ( EEL) 2 from litter in Myrica thicket on sand dune; same data except, 27–29.ix.1977 ( IMS) 2 from decaying wood and litter in fir stump.

Diagnosis Total length of adult 330–340 µm. Notogastral width about 240 µm. Integument of prodorsum, notogaster, pteromorph, venter and mentum microtuberculate. Integument of coxisternum with faint striae. Rostrum flattened, undulating, with or without minute lateral teeth. Lamella (including cusp) about 112 µm long, cusp about 80 µm long, about 48 µm wide at level of insertion of lamellar seta. Lamellar cusps diverging anteromedially; separated posteromedially, leaving prodorsum visible through oval opening, 24 µm long x 16 µm wide. Medial dens 40–45 µm, subequal to lateral dens; medial dens without teeth; lateral dens with 2–3 teeth laterally, with 0–2 small teeth medially ( Fig. 23D). Number of teeth on medial and lateral margin of lateral dens varying among specimens and on either side of same specimen. Long striae extending longitudinally along outer margin of lamella and cusp, fine striae medially ( Fig. 23D). Translamella without tooth, about 13 µm at greatest width and about 8 µm deep ( Fig. 23D). Setae ro about 56 µm long, strongly barbed along length, acuminate, strongly directly medially. Setae le about 72 µm long, thick, heavily barbed, tapered. Setae in about 133 µm long, thick (less so than le), heavily barbed, tapered; mutual distance of pair about 45 µm. Bothridial setae about 102 µm long, fusiform; head directed slightly anteromedially ( Fig. 23D). Exobothridial setae about 16 µm long, thin, weakly barbed. Genal tooth broad, rounded subrectangular, with dens ventrodistally, with longitudinal ridge ventrally. Tutorium about 115–123 µm long, of which cusp about 60–66 µm long, rectangular, distal margin with 5–7 dens. Pedotectum with striae; striae forming or not reticulations basally, reticulations about 2–3 µm at widest diameter. Custodium about 21 µm long, tapered. Porose area Al about 8 µm in diameter. Notogaster length subequal to width. Anterior margin undulating, convex lateral of bothridium, with about 10 transverse ridges. Pteromorph with small dens on anteroventral margin. Porose areas present, small, diffuse, about 5–8 µm in diameter, with Aa largest. Ten pairs of thin, smooth notogastral setae present; c about 29 µm long, l and h series about 25 µm long, p series about 19 µm long; setae positioned laterally so that lm posterior of Aa, and lp anterior of A1. Distance h 1 –h 1 about 26 µm, subequal to distance p 1 –p 1, about 25 µm. Lenticulus present, broadly V shaped. Epimeral setae about 23 µm long, barbed, 3c and 4c about 30 µm long; 4c longer thicker and more heavily barbed than other epimeral setae. Genital setae 2+4, 2 pairs of setae on anterior of genital plates; genital setae about 23 µm long, aggenital, anal and adanal setae barbed, about 16–23 µm long. Postanal porose area oval about 32 µm wide. Mentum without tectum covering base of gena, without transverse carina anteriorly. Axillary saccule about 4 x 2 µm. Leg setation (I to IV): trochanters, 1-1-2-1; femora, 5-5-3-2; genua, 2(1)-2(1)-1(1)-2; tibiae 4(2)-4(1)-3(1)-3(1); tarsi, 20(2)-15(2)-15-12. Seta l" genu I about 26 µm, l" genu II about 38 µm. Tarsi heterotridactylous.

Remarks. Hammer (1955) noted a faint reticulation on the integument of this species, which is not evident in the paratype male, or other specimens examined.

This species usually has been recognized in the literature as O. reticuloides Hammer, 1955 , which is a lapsus.

Distribution. Oribatella reticulatoides is known from Alaska to New Brunswick and is a boreal/subarctic species. It is recorded from Québec, from the Russian Far East ( Marshall et al. 1987), and possibly from Alberta ( Walter et al. 2010).