Entomobrya unifasciata Katz & Soto-Adames

Katz, Aron D., Giordano, Rosanna & Soto-Adames, Felipe, 2015, Taxonomic review and phylogenetic analysis of fifteen North American Entomobrya (Collembola, Entomobryidae), including four new species, ZooKeys 525, pp. 1-75 : 49-51

Taxon classification Animalia Collembola Entomobryidae

Entomobrya unifasciata Katz & Soto-Adames sp. n. Figs 2, 16D, 35, 36, 39

Etymology.

From the Latin words uno and fasciatus, which translates to "one band". This species has only one band found along the posterior margin of the metathorax, a character that distinguishes it from Entomobrya ligata , which has two bands; one along each posterior margin of the meta- and mesothorax.

Type material.

Holotype, ♂, USA: Kentucky, Laurel County, Levi Jackson State Park (37.08247,-84.04528), leaf litter collected at night, 28.v.2011, AK11-37.

Paratypes, USA: 2 on slides, 1 in vial, Georgia, Union Co., Brasstown Bald Rd., tiny water trickle near road surrounded by dryish leaves (34.86040,-83.80193), leaf litter, 26.v.2011 (E. C. Bernard) #2011-28; 1 on slide, Kentucky, Laurel Co., Levi Jackson State Park (37.08247,-84.04528), leaf litter collected at night, 28.v.2011, AK11-37; 1 on slide, 2 in vial, North Carolina, Henderson Co., Blue Ridge Parkway, Mill River Overlook (35.4482,-82.71963), under bark on logs, 4.vi.2007 (E. C. Bernard), 07031EB; 10 in vial, North Carolina, Swain Co., Great Smoky Mountains National Park, Balsom Mountain, Heintooga Ridge Rd. (35.57030,-83.16917), leaf litter along road, 29.v.2011, AK11-38; 1 on slide, 35 in vial, North Carolina, Swain Co., Great Smoky Mountains National Park, Balsom Mountain, Heintooga Ridge Rd. (35.57030,-83.16917), under bark, 29.v.2011, AK11-39;11 in vial, North Carolina, Swain Co., Great Smoky Mountains National Park, Balsom Mountain, Heintooga Ridge Rd. (35.57030,-83.16917), leaf litter by river, 29.v.2011, AK11-40; 1 on slide, 1 in vial, Tennessee, Sevier Co., Great Smoky Mountains National Park, 1 mi down greenbrier Rd. (35.72640,-83.40173), leaf litter by stream, 30.v.2011, AK11-41; 1 in vial, Tennessee, Sevier Co., Great Smoky Mountains National Park, 1 mi down greenbrier Rd. (35.72640,-83.40173), leaf litter stuck in nook of tree, 30.v.2011, AK11-42.

Description.

Body shape and color pattern. Body oval and cylindrical. Length up to 1.85 mm. Color pattern stable (Fig. 35), always with 3 transverse bands, 1 thin regular band along posterior margin of Th. 3, an irregular, patchy, thick band covering most of Abd. 3, and a highly irregular and sometimes broken band across medial section of Abd. 4. A small patch of pigment covers Abd. 5 and 6. Patterns usually consisting of black or dark blue pigment on a yellow background. Dark pigment usually occurring in patches along lateral margins of Th. 2 through Abd. 4. Small, rectangular black patches may occur in pairs on posterior margin of Th. 2, Abd. 1, and Abd. 2. A faint transverse band sometimes on posterior margin of Th. 2, but if present, always much lower in opacity compared to transverse band along posterior margin of Th. 3. Antennae with purple pigment, darker near apex. Legs usually white, with small purple patches on apical end of femora. A medial ring of purple pigment also occurs on tibiotarsus of hind legs.

Head. Apical bulb of 4th antennal segment usually bilobed, sometimes simple. Long differentiated smooth setae on ventral side of 1st antennal segment ≈3 × short setae. Four prelabral setae finely ciliate, seemingly smooth at low magnification under light micros copy. Ornamentation of the distal margin of the labral papillae with single seta or spine-like projection (Fig. 2). Lateral appendage of labial papilla E short, extending only ¾ papilla length. Dorsal head chaetotaxy (Fig. 36A) with macrosetae A6, M3i, S6, Ps3, Pi1, Pm1i, and Pp2, absent; S’ 0 usually absent, but observed in 2 individuals; An’ 0, a short mesoseta present medially between both An0. Eyes G and H small and subequal. Eye patch with 3 setae.

Thorax. Th. 2 macrosetae a5, m1, m2, m4, m4pi, and m4i present (Fig. 36B). Macrosetae m2i2, m4p, and m5 sometimes present; 2 additional macrosetae sometimes present on either side of m4p. Th. 3 macrosetae a1, a2, a3, a4, a4i, a5, a5e, a6, a6i, m5, m5i, m6, m6e, and m7 present (Fig. 36C); most posterior (series P) macrosetae present, p4 present or absent. Both thoracic segments with moderate number of supplemental macrosetae on zone Pm (Fig. 36B,C).

Legs. Trochanteral organ with triangular setal pattern and up to 22 setae. Unguis with 4 internal teeth; basal teeth located approximately middle of inner claw length (Fig. 16D). Unguiculus acuminate with small serrations on internal edge.

Abdomen. Abdominal chaetotaxy reduced and slightly variable. Abd. 1 with 4 macrosetae: a5, m2, m3, and m4 (Fig. 36D). Abd. 2 with 5 macrosetae: a2, m3, m3e, m3ep, and m5 (Fig. 36E); a3 usually absent. Abd. 3 with 3 macrosetae: m3, pm6, and p6 (Fig. 36F); a3 and am6 usually absent. Abd. 4 with 6 inner macrosetae (Fig. 36G).

Remarks.

Entomobrya unifasciata sp. n. can be diagnosed by the presence of only three dark transverse bands (no band across the posterior margin of Th. 2), presence of head mesoseta An’ 0, 4 macrosetae on Ab. 1, and 3 eye patch setae (see Table 2 for additional diagnostic characters). This species is part of the Entomobrya ligata complex (see remarks for Entomobrya ligata ) and is very similar to Entomobrya ligata and Entomobrya neotenica sp. n., but can be separated by characters outlined in Table 6. Though identical in chaetotaxy, molecular evidence ( Katz et al. 2015) and the absence of a dark transverse band on the posterior margin of Th. 2 separate this species from Entomobrya ligata .

Distribution.

Endemic to North America (Suppl. material 2: N). Many records of Entomobrya ligata , especially those collected from the Smokey Mountain region west to the Mississippi River, are likely to be Entomobrya unifasciata sp. n.