Willowsia pyrrhopygia, Katz, 2017

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 : 554-560

Willowsia pyrrhopygia sp. nov. Katz

Figs 5–7 , 19 , 20–35

Willowsia n. sp. 1 Katz et al. 2015a

Willowsia sp. nov. 1 Katz et al. 2015b

Type material. Holotype, USA, Florida, Okeechobee Co., Kissimmee Prairie Preserve State Park , 27.5835, - 81.05187, on vegetation, 10.viii.2011, A. Katz & J. Cech, AK11-123, 1 male on slide ( INHS 810,166 ).

Allotype, USA, Florida, Taylor Co., Econfina River State Park, 30.059533, -83.907350, on vegetation and twigs, 9.viii. 2011, A. Katz, AK 11-117, 1 female on slide ( INHS 810,167 ).

Paratypes, USA: Florida, Okeechobee Co., Kissimmee Prairie Preserve State Park, 27.5835, -81.05187, on vegetation, 10.viii.2011, A. Katz & J. Cech, AK11-123, 7 in ethanol (INHS 810,186); Florida, Okeechobee Co., Kissimmee Prairie Preserve State Park, 27.5835, -81.05187, hand collected from bark, 10.viii.2011, A. Katz & J. Cech, AK11-124, 1 on slide (INHS 810,187), 5 in ethanol (INHS 810,188); Florida, Taylor Co., Econfina River State Park, 30.059533, -83.907350, 10.viii.2011, A. Katz, hand collected from bark, adk11-116, 1 on slide (INHS 810,189); Florida, Taylor Co., Econfina River State Park, 30.059533, -83.907350, on vegetation and twigs, 9.viii.2011, A. Katz, AK11-117, 5 in ethanol (INHS 810,190).

Additional material, USA: Florida, Citrus Co., Chassahowitzka National Wildlife Refuge, W Burnt Bridge Rd. , 28.75996, -82.57583, elev. 9ft, hand collected on epiphytes, 12.viii.2011, A. Katz & J. Cech, AK11-135, 2 (1 female) on slides ( INHS 810,168–810,169 ), 17 in ethanol ( INHS 810,170 ) ; Florida, Citrus Co., Chassahowitzka National Wildlife Refuge, W Burnt Bridge Rd , 28.75996, -85.57583, on vegetation, 12.viii.2011, A. Katz & J. Cech, AK11-134, 1 female on slide ( INHS 810,171 ), 25 in ethanol ( INHS 810,172 ) ; Florida, Citrus Co., Chassahowitzka National Wildlife Refuge, W Burnt Bridge Rd , 28.75996, -85.57583, hand collected from leaf litter, 12.viii.2011, A. Katz & J. Cech, AK11-133, 1 in ethanol ( INHS 810,173 ) ; Florida, Duval Co., Jacksonville, Chicopit Bay, West off side of Highway 1A, 30.376267, -81.436500, elev. 9ft, hand collected beating vegetation, 12.viii.2011, A. Katz & J. Cech, adk11-140, 4 in ethanol ( INHS 810,174 ) ; Florida, Liberty Co., Apalochicola National Forest , 30.176650, -84.677233, 9.viii.2011, A. Katz, hand collected from bark, adk11-114, 1 on slide ( INHS 810,175 ) ; Florida, Liberty Co., Apalochicola National Forest , 30.176650, -84.677233, 9.viii.2011, A. Katz, leaf litter, adk11-115, 1 in ethanol ( INHS 810,176 ) ; Florida, Marion Co., Ocala National Forest , N of CR-314, 29.30076, -81.84686, elev. 105ft, hand collected under bark, 12.viii.2011, A. Katz & J. Cech, adk11-137, 4 in ethanol ( INHS 810,177 ) ; Florida, Marion Co., Ocala National Forest , N of CR-314, 29.30076, -81.84686, on vegetation, 12.viii.2011, A. Katz & J. Cech, AK11-138, 1 female on slide ( INHS 810,178 ), 17 in ethanol ( INHS 810,178 ) ; Florida, Marion Co., Ocala National Forest , N of CR-314, 29.30076, -81.84686, elev. 105ft, hand collected in leaf litter, 12.viii.2011, A. Katz & J. Cech, adk11-139, 1 in ethanol ( INHS 810,180 ) ; Florida, Miami- Dade Co., Everglades National Park, Pinelands Trail , 25.42298, -80.67965, on vegetation, 11.viii.2011, A. Katz & J. Cech, AK11-126, 1 on slide ( INHS 810,181 ), 14 in ethanol ( INHS 810,182 ) ; Florida, Miami-Dade Co., Everglades National Park, Pinelands Trail , 25.42298, -80.67965, hand collected from bark, 11.viii.2011, A. Katz & J. Cech, AK11-127, 1 in ethanol ( INHS 810,183 ) ; Florida, Miami-Dade Co., Big Cypress National Preserve, County Rd 94, 25.760167, -81.0386, elev. 4ft, hand collected beating vegetation, 11.viii.2011, A. Katz & J. Cech, adk11-130, 2 in ethanol ( INHS 810,184 ) ; Florida, Miami-Dade Co., Big Cypress National Preserve, County Rd 94, 25.760167, -81.0386, elev. 4ft, hand collected from epiphytes, 11.viii.2011, A. Katz & J. Cech, adk11-132, 2 in ethanol ( INHS 810,185 );

Etymology. The specific epithet is derived from the Greek adjective πυρρός, -ά, -όν, Latinized pyrrhus, -a, - um, ‘flame-colored, yellowish-red’; the Greek feminine noun, πϋγή, Latinized pyge, ‘rump, buttocks’; and the Greek adjective-forming suffix -ιος, Latinized -ius, -a, -um, ‘of, pertaining to’. The name references the conspicuous reddish-orange color of Abd. VI.

Description. Body shape and color pattern. Length up to 1.6 mm. Body dorso-ventrally -flattened ( Figs 20, 21 ). Background color white with dark purple pigment forming two lateral bands from eye spot through Abd. I; on distal end of Ant I–III, most of Ant. IV deep purple; distal end of coxa, femora, and tibiotarsus dark purple; manubrium, and lateral margins of Abd. II–VI with small purple patches. Head and body speckled with light orange pigment. Abd. VI usually with bright orange pigment. Dens without pigment. Living specimens often look dark because of a dorsal cover of black or dark brown scales.

Scales. Scales as uninterrupted ribbed type: broad, rounded, and usually apically acuminate ( Figs 5–7 ). Larger scales with straight parallel edges ( Figs 6, 7 ). Nearly all scales with straight, parallel, uninterrupted ribs from base to tip that do not converge distally. Ribs rarely interrupted near tip in larger scales. Scales present dorsally on Ant. I–II, head, body; present on trochanter and femora of middle and hind legs and ventral face of manubrium; absent from Ant. III–IV, ventral side of head, ventral tube, and fore legs.

Head. Apical bulb of Ant. IV simple, sometimes bilobed. Dorsal chaetotaxy of head as in Figure 19 : row An with 6 mac; anterior mac A0, A2, A3, A5 present; median mac M1–4 present; sutural mac S2, S4, S5 present, S 5i mac sometimes present, S6 as mic; posterior mac Ps5 present. Prelabral setae smooth. Labral papillae with 2–3 projections ( Fig. 29 ). Outer maxillary lobe with 2 sublobal hairs ( Fig. 28 ). Labial triangle as MEL1L2A1–5, r always absent ( Fig. 30 ). Lateral process of labial palp thick, blunt, not reaching tip of labial papilla E ( Fig. 31 ). Cephalic groove with 4+4 ciliate setae.

Thorax. Dorsal chaetotaxy of Th. II with 3 mac: a5, p3, p5 ( Fig. 22 ). Th. III with 5 mac: p3, p6, m5, m6, a6 ( Fig. 23 ). Trochanteral organ with triangular setal pattern with up to 26 smooth spiny setae ( Fig. 35 ). Hind claw complex as in Figure 32 .

Abdomen. Abd. I with 1 mac ( Fig. 24 ). Abd. II with 3 mac: m3, m3e, m5 ( Fig. 25 ). Abd. III with 5 mac: a2, m3, p6, pm6, am6 ( Fig. 26 ). Abd. IV with 4 mac internal to bothriotricha and at least 7 lateral mac ( Fig. 27 ). Ventral tube with 15–20 ciliate setae on each side of anterior face; 5+5 small smooth and 1+1 larger smooth setae on posterior face; lateral flaps with 7+7 smooth setae. Tenaculum as in Figure 33 . Mucro as in Figure 34 .

DNA Barcode. GenBank KM610131

Ecology. This species occurs under tree bark, in leaf litter, and on grasses, shrubs, epiphytes and other vegetation.

Distribution. Willowsia pyrrhopygia sp. nov. is known only from Florida, USA. It is very common and abundant throughout the state.

Remarks. Willowsia pyrrhopygia sp. nov. is the only member of the genus with the following combination of characters: color pattern as in Figs 20 and 21 ; uninterrupted rib scale type ( Figs 5–7 ); scales present on antennae, manubrium, and legs; labral papillae with multiple projections ( Fig. 29 ); prelabral setae smooth; labial triangle seta r absent ( Fig. 30 ); outer maxillary lobe with 2+2 sublobal hairs ( Fig. 28 ); dorsal head with 4+4 median mac, 4+4 sutural mac, mac S0 absent, and mac ps5 present ( Fig. 19 ); Th. II with 0+0 median mac and 2+2 posterior mac ( Fig. 22 ); Abd. I with 1+1 mac ( Fig. 24 ); Abd. II with 2+2 inner mac ( Fig. 25 ); Abd. III with 2+2 inner mac and 3+3 lateral mac ( Fig. 26 ); and Abd. IV with 4+4 inner mac ( Fig. 27 ).

It is most similar to W. mexicana in morphology and native distribution: both appear to be the only Willowsia species endemic to the New World, lacking labial triangle seta r, with 2 sublobal hairs, and share similarly reduced dorsal chaetotaxy. However, they can be separated by color pattern and dorsal chaetotaxay: W. pyrrhopygia sp. nov. has only small patches of dark blue pigment along the lateral margins of Abd. IV–VI, and Abd. VI has conspicuous orange pigment ( Figs 20–21 ), whereas, in W. mexicana, Abd. IV–VI are mostly covered with dark blue pigment (See figure 8 in Zhang et al., 2007); W. pyrrhopygia sp. nov. always has 4+4 median mac on head, whereas W. mexicana usually has 3+3 (M1 usually absent); W. pyrrhopygia sp. nov. has 4+4 (sometimes 3+3) sutural mac on head, lacking mac S3 and sometimes lacking S 5i, whereas W. mexicana has 5+5, with S3 and S 5i always present; W. pyrrhopygia sp. nov. has 2+2 posterior mac on Th. II (p3, p5), whereas W. mexicana has 3+3 (p3–p5).

Two species from New Caledonia, W. neocaledonia and W. nigra , are also similar to W. pyrrhopygia sp. nov. and W. mexicana , and together, these four species comprise the uninterrupted rip scale type group (sensu Zhang et al., 2011): they all have reduced dorsal chaetotaxy; smooth prelabral setae; and labral papillae with multiple projections. However, W. pyrrhopygia sp. nov. lacks labial triangle seta r, has scales on the legs, and has only 2+2 hairs on the sublobal plate of the outer maxillary lobe, whereas in W. neocaledonia and W. nigra labial triangle seta r is present, scales are absent on the legs, and there are 3+3 hairs on the sublobal plate of the outer maxillary lobe. See Table 1 for additional diagnostic characters.

The genus Americabrya Mari Mutt & Palacios-Vargas, 1987 , also endemic to the New World, has scales with similar (yet fewer) uninterrupted ribs and shares similar chaetotaxy with native New World Willowsia . Morphological comparisons among native New World Willowsia and Americabrya may provide additional insight into the complex evolutionary history of scaled Entomobryinae . It is apparent that W. pyrrhopygia sp. nov. and W. mexicana share many morphological similarities with Americabrya arida (See Table 1) that include character states that are unique, or at least undocumented, for Entomobryinae (i.e., 2 hairs on the sublobal plate of the outer maxilla and the absence of labial seta r) suggesting that W. pyrrhopygia sp. nov. and W. mexicana may be more closely related to Americabrya than to their Asian congeners. This hypothesis is supported by recent molecular phylogenetic studies ( Zhang et al. 2014b; 2015; 2016; Katz et al. 2015a; Zhang & Deharveng 2015) that dispute Willowsia ’s monophyly, proposing that some species of Willowsia may have descended from independent lineages of Entomobrya . In this case, W. pyrrhopygia sp. nov., W. mexicana and Americabrya spp., all endemic to North America, may share a New World Entomobrya ancestor. Furthermore, Zhang et al. (2011) suggests that differences in scale morphology (i.e., rib sculpturing and shape) may provide valuable insight regarding the evolution and systematics of Willowsia . For example, all Willowsia species with uninterrupted rib type scales may share common ancestry with Americabrya which have smaller and thinner, seta-like scales with only 2 uninterrupted ribs ( Fig. 14 ). However, a robust, species-level molecular phylogeny is needed to evaluate these hypotheses in the future.

Table 1. Diagnostic characters to separate species of Willowsia that occur in the New World and additional species with close affinities with W. pyrrhopygia sp. nov. Bold character states indicate those shared with W. pyrrhopygia sp. nov. Underlined character states indicate those unique to native New World Willowsia and Americabrya .

Willowsia Willowsia Willowsia Willowsia Willowsia Willowsia Willowsia Americabrya Characters pyrrhopygia mexicana neocaledonia nigra jacobsoni nigromaculata buski arida

sp. nov.

Scale rib sculpturing uninterrupted uninterrupted uninterrupted uninterrupted interrupted interrupted interrupted uninterrupted

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.

FIGURES 20 – 27. Willowsia pyrrhopygia sp. nov.: 20 – 21, Habitus; 22, Th. II dorsal chaetotaxy; 23, Th. III dorsal chaetotaxy; 24, Abd. I dorsal chaetotaxy; 25, Abd. II dorsal chaetotaxy; 26, Abd. III dorsal chaetotaxy; 27, Abd. IV dorsal chaetotaxy. Scale bars = 100 µm unless indicated.

FIGURES 28 – 35. Willowsia pyrrhopygia sp. nov.: 28, Sublobal plate of the outer maxillary lobe; 29, Labral papillae; 30, Labial triangle; 31, Lateral process of labial palp; 32, Hind claw complex; 33, Tenaculum; 34, Mucro; 35, Trochanteral organ. Scale bars = 25 µm unless indicated.