Entomobrya multifasciata (Tullberg), 1871

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 : 38-42

Taxon classification Animalia Collembola Entomobryidae

Entomobrya multifasciata (Tullberg), 1871 Figs 2, 27, 28, 39

Description.

Body shape and color pattern. Body oval and cylindrical. One primary color form, with slight variations (Fig. 27); yellow background with black, dark brown or purple pigment forming 5 transverse bands along posterior margins of Th. 2 through Abd. 3. Abd. 4 pattern variable, but usually with 2 triangular patches of pigment along posterior margin of segment that point anteriorly toward a W-shaped mark or broken and irregular transverse band. Abd. 5 and Abd. 6 mostly covered with dark pigment. Dark pigment present along lateral margins of all segments, sometimes in broken patches. Antennae light brown or purple pigment increasingly dark towards the apex.

Head. Apical bulb of 4th antennal segment usually bilobed, sometimes simple. Long differentiated smooth setae on ventral side of 1st antennal segment ≈2 –3× short setae. Four prelabral setae ciliate. Ornamentation of the distal margin of the labral papillae with 2-3 seta or spine-like projections (Fig. 2). Labial lateral appendage slightly curved, relatively thin, reaching just beyond tip of papilla. Dorsal head macrosetae (Fig. 28A) An’ 0, A3a2, A3a3, M3i, S’ 0, S4i, S6, Ps3, Pi1, and Pm1i absent; S1 and Pm1 usually present, but may be asymmetrical. Eyes G and H small and subequal. Eye patch with 5 setae.

Thorax. Th. 2 macrosetae a5, m1, m2, m4, and m4p present (Fig. 28B); m1i and m2i sometimes present; posterior macrosetae (series P) present. Th. 3 macrosetae a1, a2, a3, a 4, a5, a6, m5, m5i, m6, m6e, and m7 present (Fig. 28C); a4i, a5e, and m4 sometimes present; posterior macrosetae (series P) present. Zone Pm of both thoracic segments with moderate number of supplemental macrosetae (Figs 3; 39B,C).

Legs. Trochanteral organ with triangular setal pattern and up to 18 setae.

Abdomen. Abd. 1 with 6-8 macrosetae (Fig. 28D). Abd. 2 macroseta a2, a3, m3, m3e, and m5 are present (Fig. 28E). Abd. 3 macroseta a1, a2, a3, m3, am6, pm6, and p6 present (Fig. 28F). Abd. 4 with 8-12 inner macroseta (Fig. 28G). Mucronal teeth subequal.

Remarks.

Entomobrya multifasciata can be distinguished by the color pattern described above combined with the presence of Abd. 3 macrosetae a1 and a2 and the absence of macrosetae head S4i, Th. 2 m5, and Abd. 2 m3ep (see Table 2 for additional diagnostic characters). Chaetotaxy and color pattern observed in this species is almost indistinguishable from that in female Entomobrya atrocincta . Furthermore, variation in chaetotaxy displayed in Entomobrya atrocincta obscures most potentially diagnostic characters needed to distinguish Entomobrya multifasciata from Entomobrya atrocincta . However, Entomobrya multifasciata can be recognized by the presence of head macroseta S4i and the morphology of labral papillae; Entomobrya multifasciata has two to three larger seta or spine-like projections per papillae, while Entomobrya atrocincta has three to four smaller seta or spine-like projections per papillae (Fig. 2). Table 3 provides additional diagnostic characters separating Entomobrya multifasciata from Entomobrya nivalis and Entomobrya intermedia , which share superficially similar color patterns but can be separated by chaetotaxy.

We were unable to obtain North American samples of Entomobrya multifasciata and the description and diagnosis provided above are based on specimens from São Miguel Island, Azores, Portugal. The Nearctic distribution of this species remains unclear in light of the sexual dimorphism of Entomobrya atrocincta described in this study (see remarks for Entomobrya atrocincta ). Christiansen and Bellinger (1998) report a widespread distribution, with localities found across the United States, but they also note that their records may be questionable as a result of likely misidentification. Christiansen and Bellinger (1998) describe the labral papillae of Entomobrya multifasciata as having three to four small seta or spine-like projections, a condition that resembles those in Entomobrya atrocincta , possibly indicating an identification error. In the Collembola of North America, Christiansen and Bellinger (1998) report a male genital plate, presumably from an individual with the Entomobrya multifasciata pattern collected in Massachusetts, which eliminates the possibility that the specimen could have been a female Entomobrya atrocincta . Since a number of samples were collected in the Northeastern United States ( Christiansen and Bellinger 1998), the presence of Entomobrya multifasciata in North America cannot be ruled out. However, in the course of the present study, all specimens collected bearing the banded color pattern were female Entomobrya atrocincta and were usually accompanied by male Entomobrya atrocincta .

Distribution.

North America ( Christiansen and Bellinger 1998), Hawaii ( Christiansen and Bellinger 1992), Europe and Russia ( Jordana 2012). Records from North America and Hawaii are questionable due to likely misidentification of Entomobrya atrocincta females. See Suppl. material 2: J for a distribution map and below for a list of material examined with collection and locality information.

Material examined.

PORTUGAL: 2 on slides, 10 in vial, Azores, São Miguel Island, (J. Marcelino), vial #119; 6 on slides, 10 in vial, Azores, São Miguel Island, (J. Marcelino), vial #86; 5 in vial, Azores, São Miguel Island, (J. Marcelino), vial #55; 4 in vial, Azores, Terceira Island, (J. Marcelino), vial #9; 4 in vial, Madeira Island, (J. Marcelino), vial #2.