Willowsia mexicana Zhang, Palacios-Vargas & Chen, 2007

Katz, Aron D., 2017, A new endemic species of Willowsia from Florida (USA) and descriptive notes on all New World Willowsia (Collembola: Entomobryidae), Zootaxa 4350 (3), pp. 549-562 : 552-553

Willowsia mexicana Zhang, Palacios-Vargas & Chen, 2007

Figs 8–10 , 18

Material examined. Paratype, Mexico : Oaxaca, Oaxaca , Mexico, 06/05/1994, ex. Pinus oaxacana, E. López Col. , 19127, 1 on slide. Additional material , Mexico : Cd. de México , L. NW. iztaccihuatl, alt. 3020 m, a : 1 m:1, 19057, 27 agosto 2005, 1 on slide; Cd. de México , L. NW. iztaccihuatl, alt. 3440 m, a : 6 m:6, 19097, 27 agosto 2005, 1 on slide; Veracruz, EBLT EBLT, 18°58.56N, 95°4’35.62’’O, Trampa Pitfall 2, 248 msnm Selva Alta perennifolia, M. Madora, col, 16–21IV–2015, 2 on slides.

Complements to description. Scales present on dorsal side of Ant. I and Ant. II, and middle and hind legs (coxae, trochanter, femora). Outer maxillary lobe with 2 sublobal hairs. Ribs on scales straight, parallel, not converging distally, most running uninterrupted from base to tip ( Fig. 8–10 ); some scales with ribs interrupted near tip ( Fig. 8 ). Dorsal chaetotaxy as described in Zhang et al. (2007), except dorsal head mac M1 sometimes present ( Fig.18 ) and Th. II with 4+4 posterior mac (p3–6).

Ecology. This species occurs under tree bark, mangrove leaf litter, and has been collected at high elevations (750–3500 m above sea level).

Distribution. Mexico.

Remarks. Willowsia mexicana is the only member of the genus with the following combination of characters: Abd. IV–VI with evenly dark pigment; uninterrupted rib type scales ( Figs 8–10 ); scales present on antennae, legs, and furcula; labral papillae with multiple projections; prelabral setae smooth; labial triangle seta r absent ; outer maxillary lobe with 2+2 sublobal hairs; dorsal head with 3+3 (rarely 4+4) median mac, 5+5 sutural mac, mac S0 absent, and mac Ps5 present ( Fig. 18 ); Th. II with 0+0 median mac and 3+3 posterior mac; Abd. I with 1+1 mac; Abd. II with 2+2 inner mac; Abd. III with 2+2 inner and 3+3 lateral mac; and Abd. IV with 4+4 inner mac.

This species is most similar to W. pyrrhopygia sp. nov. (differences between the two species are listed in the remarks for W. pyrrhopygia sp. nov.).

W. mexicana was previously described as having scales with only uninterrupted ribs ( Zhang et al., 2007, 2014a), but new observations of the type material show some larger scales do have broken ribs near the apex. Willowsia mexicana , W. nigra , W. neocaledonia and W. pyrrhopygia sp. nov. are the only species in this genus with uninterrupted rib type scales.

Zhang et al. (2007) also describe scales as present on the ventral face of the manubrium, but do not specify scale morphology (e.g., broad vs. thin). Although, I was unable to confirm the presence of scales (i.e., typical broad scales like those observed on body) on the ventral face of the manubrium in the type material, I did observe setaelike or narrow scales, similar to those observed on the ventral face of the manubrium in other Willowsia species (Zhang 2015).

Figures

FIGURES 5 – 14. Scales: 5 – 7, Willowsia pyrrhopygia sp. nov.; 8 – 10, Willowsia mexicana; 11, Willowsia jacobsoni; 12, Willowsia buski; 13, Willowsia nigromaculata; 14, Americabrya arida. Scale bars = 1 µm.

FIGURES 15 – 19. Head dorsal chaetotaxy: 15, Willowsia buski; 16, Willowsia jacobsoni; 17, Willowsia nigromaculata; 18, Willowsia mexicana; 19, Willowsia pyrrhopygia sp. nov. Scale bars = 100 µm.