Agrenia tarashchukae, Fjellberg, Arne & Bernard, Ernest C., 2009

Fjellberg, Arne & Bernard, Ernest C., 2009, Review of Agrenia Börner, 1906 with descriptions of four new species from North America (Collembola, Isotomidae), Zootaxa 2306, pp. 17-28 : 27

Agrenia tarashchukae n. sp.

Figs. 1 G, I; 6A

Type material. Holotype: Female (slide) and 10 paratypes on 6 slides from USA, New York, Minnewaska State Park Preserve, Awosting Falls, moss in the spray zone, 27.V.1996, M. Tarashchuk, coll. Holotype and 6 paratypes deposited in the National Museum of Natural History, Washington, D.C.; remaining paratypes deposited in the University of Tennessee Entomology Collection.

Description. Largest specimen seen 1.7 mm. Precise colour not observed as only slide specimens were available, but appearing to have been of uniform colour without marked pattern. Head shape normal, not prognathous. Antennae 1.8–1.9 times the length of head diagonal. Maxilla unmodified, lamellae short. PAO oval, about as long as diameter of nearest ocellus. Setae on body dense, moderately stout, and short; those on head and thorax clearly differentiated into short and long setae. Frontoclypeal setae unmodified. Ventral tube with 2–4 anterior setae on each side, 12–24 lateral setae, and more than 35 caudal setae in large specimens. Retinaculum with more than 30 setae in large specimens. Differentiated subapical seta on dens short, not passing tip of mucro. Mucro elongate, with strong, undulating ventral and lateral lamellae ( Fig. 1 G); apical and subapical teeth of mucro subequal; outer dorsal lamella high and prominent ( Fig. 6 A). Mucronal seta absent. Claws normal, not elongated ( Fig. 1 I). Claw index 1.9–2.3. Only non-reproductive females and juveniles seen.

Etymology. Named after the collector, our colleague Dr. Marina Taraschchuk, Kiev.

Discussion. The short subapical seta on the dens, which does not bypass the tip of the mucro, is a character shared only with A. falcula n. sp. From this species A. tarashchukae n. sp. differs by having more robust claws (claw index less than 2.5), stronger dorsal lamella on mucro, and coarser body setae. In some Agrenia spp. these characters may depend on season or reproductive stage of the individual, but the samples of A. falcula and A. tarashchukae were made in summer and reproductive males of the former species do not differ from unreproductive individuals.

Distribution and ecology. The single collection of this species was made from wet moss in the spray zone. The type locality is in the Shawanagunk Mountains, in the northeastern part of the Appalachian Range.

Figures

FIGURE 1. A-G, mucro shapes of Agrenia spp. A. A. extrema n. sp., lateral view; B. A. extrema n. sp., dorsal view; C. A. parkeri n. sp., winter form; D. A. parkeri n. sp., summer form; E. A. falcula n. sp., ventral view showing the broad ventral lamella; F. A. falcula n. sp., lateral view; G. A. tarashchukae n. sp. H-K, claws of hind legs. H. A. falcula n. sp.; I. A. tarashchukae n. sp.; J. A. parkeri n. sp., winter form; K. A. extrema n. sp. L-N, maxillae. L. A. extrema n. sp., ventral side (left) and inner side (right); M. A. agilis, inner side; N. A. falcula n. sp., ventral side.

FIGURE 6. Agrenia spp. A-C, mucrones. A. A. tarashchukae n. sp.; B. A. agilis; C. A. falcula n. sp.; D-E. Tips of Ant. IV. D. A. extrema n. sp.; E. A. agilis. Scale bars = 20 μm.