Willowsia buski ( Lubbock, 1870 )

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 : 550-552

Willowsia buski ( Lubbock, 1870)

Figs 1 , 12 , 15

Material examined. USA: Wisconsin, Sauk Co., Parfrey’s Glen Natural Area, off Bluff Rd., 43.421102, - 89.636841, on bark, 12.vi.2011, A. Katz, AK11-52, 4 on slides ( INHS 810,141–810,144); Illinois, Champaign Co., Urbana, Meadowbrook organic gardens, 40.08066, -88.20836, hand collected from mulch and leaf litter, 14.iii.2012, A. Katz, AK12-24, 1 on slide ( INHS 810,145), 6 in ethanol ( INHS 810,146); Illinois, Champaign Co., Urbana, Brownfield Woods, 40.14326, -88.16441, on bark from dead tree, 10.ix.2009, F. Soto-Adames, 1 on slide ( INHS 810,147).

Complement to description based on American specimens. Habitus as in Figure 1 . Scales long basal rib type ( Fig. 12 ). Scales absent on antennae, legs, and furcula. Dorsal chaetotaxy of the head as in Figure 15 : row An with 5 mac; anterior mac A0, A2, A3, A5 present; 3+3 median mac, M1, M2, M4 present, M3 always absent; sutural mac S0, S2, S3, S 4i, S4, S 5i, S5 present, S6 as mic; posterior mac Ps5 present. Outer maxillary lobe with 3 sublobal hairs. Prelabral setae ciliate. Labral papillae each with single seta-like projection. Labial triangle as MrEL1L2A1–5, r always present. Lateral process of labial palp straight, blunt, and reaching tip of labial papilla E. Cephalic groove with 6+6 ciliate setae.

Ecology. This species occurs under tree bark, in leaf litter, and on vegetation.

Distribution. Cosmopolitan, including the Americas.

Remarks. Willowsia buski is the only member of the genus with the following combination of characters: uniformly blue color pattern ( Fig. 1 ); long basal rib type scales ( Fig. 12 ); scales absent on antennae, legs, and furcula; labral papillae with single, seta-like projections; prelabral setae ciliate; labial triangle seta r present ; outer maxillary lobe with 3+3 sublobal hairs; dorsal head with 3+3 median mac, 6+6 sutural mac, mac S0 and Ps5 present ( Fig. 15 ); Th. II with 2+2 median mac and 8+8 posterior mac; Abd. I with 2+2 mac; Abd. II with 3+3 inner mac; Abd. III with 2+2 inner and 3+3 lateral mac; and Abd. IV with 5+5 inner mac.

In the Americas, this species is most similar to W. nigromaculata : both have basal long rib scale type ( Zhang et al., 2011); scales absent on antennae, legs, and manubrium; labral papillae each with a single seta-like projection; ciliate prelabral setae, labial triangle r seta present, 3+3 sublobal hairs of outer maxilla; 3+3 median mac, 6+6 sutural mac, and S0 mac present on dorsal head; 3+3 inner mac on Abd. II; and 3+3 lateral mac on Abd. IV. They can be differentiated by color pattern and chaetotaxy: W. buski is uniformly dark blue or purple without a clear pattern ( W. nigromaculata has a distinct dorsal pigment pattern); has dorsal head mac Ps5 (absent in W. nigromaculata ), has 2+2 median mac on Th. II ( W. nigromaculata has 1+1), 2+2 mac on Abd. I ( W. nigromaculata has 3+3), 2+2 inner mac on Abd. III ( W. nigromaculata has 3+3), and 5+5 inner mac on Abd. IV ( W. nigromaculata has 7+7). See Table 1 for additional diagnostic characters.

The specimens observed for this study matched morphological descriptions, including dorsal chaetotaxy, by Christiansen & Bellinger (1998) and Zhang et al. (2011).

Figures

FIGURES 1 – 4. Habitus: 1, Willowsia buski; 2, Willowsia nigromaculata; 3, Willowsia jacobsoni (male); 4, Willowsia jacobsoni (female). Scale bars = 200 µm.

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.