Desoria ater, Fjellberg, Arne, 2010

Fjellberg, Arne, 2010, Cryophilic Isotomidae (Collembola) of the Northwestern Rocky Mountains, U. S. A., Zootaxa 2513, pp. 27-49 : 34-36

publication ID	https://doi.org/ 10.5281/zenodo.196078
DOI	https://doi.org/10.5281/zenodo.3502711
persistent identifier	https://treatment.plazi.org/id/504F2D6C-FFDE-FF80-97BE-F2BBFADA1DD1
treatment provided by	Plazi
scientific name	Desoria ater
status	sp. nov.

Treatment

Desoria ater sp. n.

( Figs. 35–43 View FIGURES 30 – 56 , 113 View FIGURES 110 – 114 , 115D View FIGURE 115. A – H )

Type material (in alcohol, sex not checked). Holotype and 11 paratypes from "Alaska Mountains,. between Mendenhall Glacier and Montana Creek Trail, 58o29'N, 134o40'W, on goat dung in snowfields, 1,000 m alt., 14.VII.1980, A. Fjellberg leg." ( INHS).

Description. Body size up to 1.7 mm. Body shape slender, typical Desoria with abdomen slightly pearshaped ( Fig. 115D View FIGURE 115. A – H ). Head shape normal, not prognathous/hypognathous. Abd. 5–6 completely fused, without a gap in setal cover. Colour uniformly dark greyish black. Antennae, legs (beyond coxae) and furca paler, greyish green; antennal segments all of same colour. Head with two small white spots between the eye-fields ( Fig. 113 View FIGURES 110 – 114 ). Ocelli 8+8, G & H slightly smaller, arrangement characteristic, with ocelli ABCDE forming a triangle. PAO oval, as long as diameter of nearest ocellus. Two setae near ventral edge of PAO ( Fig. 41 View FIGURES 30 – 56 ). Ant. 1 with a group of 5–6 short ventroapical sensilla and more than 10 setaceous sensilla ( Fig. 36 View FIGURES 30 – 56 ). Ant. 2 and 3 with several lateral and ventrolateral setaceous sensilla ( Figs. 37–38 View FIGURES 30 – 56 ). Ant. 4 with bifurcate subapical pin seta, subapical organite small, globular. Labrum with 4/554 slender normal setae, apical edge with 4 sharp folds and a composite ventral ciliation. Frontoclypeal field with more than 10 setae ( Fig. 40 View FIGURES 30 – 56 ), two setae present between antennal base and upper corner of labrum. Maxillary palp bifurcate, four sublobal setae. Labial palps complete, guard e7 present, four proximal setae; terminal setae of the papillae as long as guards. Hypostomal papilla with subequal H and h1/h2. Basal fields of labium with 5 medial and 5 lateral setae. Ventral side of head with 4–8 postlabial setae on each side. Mandibles normal, strong. Maxillae unmodified, with 3-toothed capitulum and short lamellae covered with fine denticles. Body integument smooth, macrochaetae very long with fine ciliation, mostly on anterior side ( Figs. 35, 39 View FIGURES 30 – 56 ). Median macrochaetae on abd. 5 are 3.5–4.0 as long as inner length of last claw. Ground cover of setae smooth and dense, on head and anterior part of the body notably double with short setae and longer dagger-like setae (as Fig. 30 View FIGURES 30 – 56 ). Sensilla on the tergites hard to separate from ordinary setae, but numbers appear to be low, around 5 on each tergite from th. 2–abd. 5, positioned slightly anterior to the p-row of setae. Anterior sensilla appear to be absent on the tergites. Spinelike microsensilla as 11/100. Ventral tube on each side with 2–4 frontal and 10–12 lateral setae. Posterior side with 6–8 setae (upper four in a transverse row). No ventral setae on thorax. Retinaculum with 4+4 teeth and 15–20 setae. Manubrium with blunt ventroapical teeth and usually 2+2 short ventroapical setae. Ventromedian field with more than 40 setae. Dens crenulated, with 10–12 dorsal setae in proximal half; subapical microseta present; ventroapical seta not prolonged. Mucro short and compact, with 4 sharp teeth ( Fig. 42 View FIGURES 30 – 56 ); inner basal tooth small; inner lateral lamella not transformed to a tooth, ending at tip of the subapical tooth; lateral seta absent. Tibiotarsi with 11 apical setae, all acuminate. Inner side of tib.1–2 with more than 3+3 setae along median line. Claws normal, with distinct lateral teeth, no inner tooth; unguiculus with low dorsal lamella, sometimes toothed ( Fig. 43 View FIGURES 30 – 56 ). Nine examined specimens examined are all females.

Etymology. The name ater (Latin: black) reflects the dark colour of the animal.

Discussion. The dark colour which includes the antennae, short 4-toothed mucro, increased number of antennal sensilla, eye configuration and particularly the very long and densely ciliated macrochaetae serve to distinguish this species.

Distribution and ecology. Only known from the type locality where large number of specimens occurred on droppings from mountain goat deposited on glacier ice in the mountains east of Juneau, Alaska.