Lacronia Strand, 1942

Carvalho, Rafael N. & Kury, Adriano B., 2023, Between areolated and band-shaped spots: a revision of Lacronia Strand, 1942 (Opiliones, Gonyleptidae), European Journal of Taxonomy 859, pp. 1-56 : 23-26

Genus Lacronia Strand, 1942

Luederwaldtia Mello-Leitão, 1923a: 518 [junior homonym of Luederwaldtia Schmidt, 1922 (Hemiptera) ] [type species: Luederwaldtia serripes Mello-Leitão, 1923 , by original designation]. Luederwaldtia originally in Pachylinae.

Lacronia Strand, 1942: 397 [available replacement name for Luederwaldtia Mello-Leitão, 1923 ].

Luederwaldtia – Mello-Leitão 1926: 337; 1932: 166; 1935a: 99. — Roewer 1929: 218. — Kästner 1937: 389. — Soares & Soares 1954: 269. — H. Soares 1966: 286. — Muñoz-Cuevas 1973: 226.

Lacronia – Kury 2003a: 174; 2003b: 29. — Kury & Orrico 2006: 148.

Diagnosis

Lacronia resembles Discocyrtus s. str. due to: 1) stylus straight on the glans ( Fig. 11A–B ); 2) apical portion of the stylus only as an undifferentiated extension of its stem ( Fig. 3A–D ); 3) ventral process of the glans with the same diameter of the stylus ( Fig. 20A, D ); 4) ocularium height (in lateral view) with thrice or more the eyes diameter length ( Fig. 7B, E ); 5) Fe II–III with a retro-dorsal distal spur ( Fig. 3A ); 6) Pa IV covered by acuminated tubercles on the dorsal view ( Fig. 12G–H, J ).

Lacronia can be differentiated from Discocyrtus s. str. by: 1) mesotergum area III (on males) with a pair of paramedian spines (a pair of subconical structures in L. ceci ) ( Fig. 4B–G ); 2) mesotergum area IV of the mesotergum not invading the posterior border of the dorsal scutum (area IV invading the posterior border of the dorsal scutum in L. boraceae comb. nov.) ( Fig. 4A–D, F–G ); 3) Ti III maceshaped ( Fig. 12D ); 4) Cx IV with acuminated tubercles on the prolateral border ( Fig. 12A ); 5) Cx IV with a prodorsal apophysis crenated on the posterior portion ( Fig. 12A ); 6) Cx IV with a prodorsal apophysis transversally inserted in relation to the main body axis ( Fig. 7A ); 7) Tr IV approximately quadrangular-shaped ( Fig. 12G, I ); 8) Fe IV approximately straight (in dorsal view) ( Fig. 17F ).

Etymology

Luederwaldtia in honor of German born Brazilian zoologist Herman Luederwaldt (1858–1938). Gender feminine. Lacronia of obscure origin, possibly from a proper name ‘Lacrona’. Gender feminine.

Included species

Lacronia boraceae (B. Soares, 1942) comb. nov., Lacronia camboriu Kury, 2003 , Lacronia ceci Kury & Orrico, 2006 , Lacronia nigra (Mello-Leitão, 1923) comb. nov., Lacronia ricardoi Kury, 2003 , Lacronia serripes (Mello-Leitão, 1923) (type species) and Lacronia tenuis ( Roewer, 1917) comb. nov.

Geographic distribution

BRAZIL: states of Rio de Janeiro, Santa Catarina and São Paulo ( Fig. 5 ).

Key for males of species of Lacronia

1. Ocularium convex (in frontal view) without medial depression, with a pair of tubercles/spines fused at the base; mesotergum area II invading laterally the posterior portion of the area I; mesotergum area III with a pair of spines with acuminated apex; Fe and Mt IV dorsally armed with spines ..... 2

– Ocularium convex (in frontal view) with medial depression, with an independent pair of tubercles; mesotergum area II not invading laterally the posterior portion of the area I; mesotergum area III with a pair of spines with rounded apex; Fe and Mt IV dorsally unarmed .... L. ceci Kury & Orrico, 2006

2. Glans’ stylus with apical portion swollen in relation is stem; mesotergum without areolate pattern of spots surrounding the tubercles; mesotergum area III with a pair of spines with slight distal inflection to ventral portion; free tergites I–III with a transversal row of ordinary tubercles; Fe IV with proximal and distal portions with approximately the same diameter; Ti IV dorsally covered by regular tubercles ................................................................................................................................ 3

– Glans’ stylus with apical portion without an undifferentiated apex; mesotergum without areolate pattern of spots surrounding the tubercles; mesotergum area III with a pair of straight spines; free tergites I–III with a pair of highlighted tubercles on the paramedian portion; Fe IV with distal portion larger (in diameter) than the proximal; Ti IV dorsally covered by acuminated tubercles and/ or spines ............................................................................................................................................ 5

3. Mesotergum with band-shaped marks contrasting the background color; mesotergum areas II–IV without ordinary tubercles; mesotergum area II not invading laterally the anterior portion of the area III; Tr IV prolateral proximal apophysis hook-shaped .............................................................. 4

– Mesotergum with uniform background color; mesotergum areas II–IV with ordinary tubercles (contrasting with the background color) on the paramedian portion; mesotergum area II invading laterally the anterior portion of the area III; Tr IV prolateral proximal apophysis isosceles-triangleshaped with a medial anterior bud .................................................. L. serripes (Mello-Leitão, 1923)

4. Scutal areas III–IV with band-shaped marks contrasting the background color; mesotergum area I with a pair of conspicuous tubercles; leg III with twice or more the diameter of the leg II; Pa IV retro-ventral portion unarmed ...................................................................... L. camboriu Kury, 2003

– Scutal areas III–IV with uniform background color; mesotergum area I without tubercles; leg III with 1.5× the diameter of the leg II; Pa IV retro-ventral portion with a row of tubercles ................. ......................................................................................................................... L. ricardoi Kury, 2003

5. Mesotergum area I with one or two pair(s) of highlighted tubercles; mesotergum area III without any dorsal expansion; Mt IV dorsal row of spines composed only by regular spines or tubercles ......... 6

– Mesotergum area I covered by ordinary tubercles; mesotergum area III posteriorly expanded with a paramedian dorsal monticule; Mt IV dorsal row of spines with the third spine bifid ........................ ........................................................................................... L. boraceae (B. Soares, 1942) comb. nov.

6. VP without macrosetae A on the medial portion; mesotergum tubercles and areolate spots with same color; mesotergum area I with a pair of conspicuous tubercles; Cx IV prolateral apophysis with a tiny spine on the apex; Tr IV prolateral distal portion with a hook-shaped apophysis ....................... ........................................................................................... L. nigra (Mello-Leitão, 1923) comb. nov.

– VP with macrosetae A1 on the medial portion; mesotergum with tubercles’ color contrasting with the areolate spots; mesotergum area I with two pairs of conspicuous tubercles; Cx IV prolateral apophysis regular, without a tiny spine on the apex; Tr IV prodorsal distal portion with transversal apophysis (covered by four prominent tubercles) ................... L. tenuis ( Roewer, 1917) comb. nov.

Figures

Fig. 11. Lacronia ceci Kury & Orrico, 2006, ♂ (MNRJ 6945ꜝ), penis, distal part. A. Dorsal view. B. Lateral view. C. Ventral view. D. Detail of stylus and ventral process, latero-dorsal view. Scale bars: A–C = 50 μm; D = 20 μm.

Fig. 3. Lacronia spp., specimens in vivo. A–D. L. nigra (B. Soares, 1942) comb. nov., ♂, from Brazil, São Paulo, Santo André, Alto da Serra. E–H. L. tenuis (Roewer, 1917) comb. nov., ♂, from Brazil, Rio de Janeiro, Mangaratiba. Source: Adriano Kury.

Fig. 20. Lacronia tenuis (Roewer, 1917) comb. nov., ♂ (MNRJ 5533ꜝ), penis, distal part. A. Dorsal view. B. Left lateral view. C. Ventral view. D. Detail of stylus and ventral process, dorso-lateral view. Scale bars:A–C = 100 μm; D = 20 μm.

Fig. 7. Lacronia boraceae (B. Soares, 1942) comb. nov., ♂ (MNRJ-HS 122ꜝ). A. Habitus, dorsal view. B. Ocularium, frontal view. C. Armature of mesotergum area III, posterior view. D. Right Fe III, prodorsal view. E. Habitus, lateral view. F. Left Fe IV, proventral view. G. Right Fe IV, retro-ventral view. H. Right Pa–Ti IV, proventral view. I. Right Pa–Ti IV, ventral view. Scale bars: A, E = 4 mm; B–C = 1 mm; D, H–I = 2 mm; F–G = 3 mm.

Fig. 12. Lacronia nigra (B. Soares, 1942) comb. nov., ♂ (MNRJ 60385). A. Habitus, dorsal view. B. Ocularium, frontal view. C. Armature of mesotergum area III, posterior view. D. Fe–Ti III, prodorsal view. E. Habitus, lateral view. F. Detail of the Cx IV prodorsal distal apophysis, posterior view. G. Right Fe–Ti IV, dorsal view. H. Same, prolateral view. I. Same, ventral view. J. Same, retro-lateral view. K. Right Mt–Ta IV, retro-lateral view. Scale bars: A, D–E, K = 2 mm; B–C, F = 1 mm; G–J = 3 mm.

Fig. 4. Lacronia spp., schematic illustrations of the ♂ DS, showing the background variation and tubercles patterns of the specimens in vivo (except for L. boraceae (B. Soares, 1942) comb. nov., which information was only available in alcohol). A. L. ceci Kury & Orrico, 2006. B. L. camboriu Kury, 2003. C. L. ricardoi Kury, 2003. D. L. serripes (Mello-Leitão, 1923). E. L. boraceae comb. nov. F. L. nigra (B. Soares, 1942) comb. nov. G. L. tenuis (Roewer, 1917) comb. nov. Scale bars = 1 mm.

Fig. 17. Lacronia serripes(Mello-Leitão, 1923), ♂ (MZSP14342). A. Habitus, dorsal view.B. Ocularium, frontal view. C. Armature of mesotergum area III, posterior view. D. Habitus, lateral view. E. Left Fe– Ti III, proventral view. F. Right Fe–Ti IV, dorsal view. G. Same, prolateral view. H. Same, ventral view. I. Same, retro-lateral view. J. Right Mt–Ta IV, retro-lateral view. Scale bars: A, D–E, J = 2 mm; B–C = 1 mm; F–I = 3 mm.

Fig. 5. Southeasten and Southern regions of Brazil, showing the distribution of the Lacronia spp. The area shaded in green represents the Atlantic province, as proposed by Morrone et al. (2022).