Ora platensis Brèthes, 1925

Libonatti, María Laura, 2015, A revision of the genus Ora Clark, 1865 (Coleoptera: Scirtidae) in Argentina (part II) — redescriptions, updated distributions and a key to species, Zootaxa 3985 (1), pp. 69-97 : 86-89

Ora platensis Brèthes, 1925

( Figs. 18, 19 , 93–106 )

Ora platensis Brèthes, 1925: 13

Type material. Holotype: ♂ ( MACN), “Bs As / 24.III. 923 / J. B.” [white label, handwritten]; “ Ora / platensis Brèthes ” [white label, handwritten by Brèthes], “ Type!” [white label, handwritten by Brèthes], with a square piece of red paper, “ TYPUS ” [pink label, printed].

Additional material studied. ARGENTINA: 1 ♀ (BR), “R EP ARGENTINA / Prov. Buenos Aires / I.1898 / C. Bruch” [white label, printed]; 1 ♂ (BR), “R EP ARGENTINA / Prov. Buenos Aires / II.1904 / C. Bruch” [white label, printed], “Scyrtes sp.” [white label, handwritten by Bruch], “ Scirtes sp. / à reetudier” [white label, handwritten by Pic]; 1 ♀ (BR), “R EP ARGENTINA / Prov. Buenos Aires / 19.XI.1904 / C. Bruch” [white label, printed]; 1 ♀ (BR), “R EP ARGENTINA / Prov. Buenos Aires / 190 / C. Bruch” [white label, printed]; 2 ♂ and 1 ♀ (BR), “R EP ARGENTINA / Prov. Buenos Aires / 30.XII.1922 / C. Bruch” [white label, printed]; 1 ♂ ( MACN), “INTA-DELTA / 7–10/12/72 ” [white label, handwritten]; 1 ♀ ( MACN), “Tigre”; 1 ♂ ( MLLC), Buenos Aires, Reserva El Destino, 20.xi.2011, light trap, M. L. Libonatti; 1 ♀ ( MLLC), Ciudad Autónoma de Buenos Aires, Reserva Ecológica Costanera Sur, Laguna de los Patos, 10.xi.2014, S. A. Mazzucconi.

Diagnosis. Body oblong, brown with several testaceous spots on elytra—on the basal margin, on the humeral margin, on the disc forming a zigzag or trifurcate mark and on the apex ( Figs. 18, 19 ); tegmen and penis tightly attached to each other, lateroapical surface of aedeagus spiny, tegmen slightly asymmetrical, with a subapical digitiform outgrowth, lateral margins spiny; penis strongly asymmetrical, foot-shaped, vertical piece with a long left-handed protuberance ( Figs. 99, 100 ); anterior part of bursal sclerite with one central small tooth and an evenly rounded margin, middle part with a pair of teeth ( Figs. 104, 105 ); prehensor composed of two dorso-ventral laminar oval sclerites, surface covered with minute conical microtrichia ( Fig. 106 ).

Redescription. Measurements. Males (n = 6): TL 3.71–3.90 [3.71] (mean 3.80) mm, PL 0.62–0.73 [0.62] (mean 0.69) mm, PW 1.39–1.74 [1.39] (mean 1.57) mm, EL 3.01–3.28 [3.01] (mean 3.20) mm, EW 2.08–2.59 [2.08] (mean 2.30) mm. Females (n = 6): TL 4.09–4.87 (mean 4.44) mm, PL 0.69–0.88 (mean 0.78) mm, PW 1.70– 2.00 (mean 1.82) mm, EL 3.47–4.14 (mean 3.73) mm, EW 2.51–2.92 (mean 2.66) mm.

Habitus. Oblong, maximum width at middle of elytra, closely covered with yellowish setae.

Coloration. Body dark brown, except several testaceous spots on elytra—on the basal margin, on the humeral margin, on the disc forming a zigzag, and on the apex, and the testaceous basal half of the hind femora.

Head. Wide, approximately 1.7x wider than interocular space, clypeal surface convex; punctation very fine. Antennae filiform, with apical margins of antennomeres 4–10 not projected anteriorly (segments 3–11 missing in holotype). Mandibles with acute apex.

Thorax. Pronotum approximately 2.2x wider than long, anterolateral angles very slightly projecting anteriorly, lateral margins very roundly-curved; punctation fine, punctures separated by 2.0x diameter. Scutellar shield with punctation similar to that on pronotum. Elytra depressed anterolaterally, humerus marked, lateral margins rounded; punctation uniform, much coarser than on head, pronotum and scutellar shield, punctures separated by 0.5–1.0x diameter. Mesoventral process elongate, thin, with truncate apex. Approximate length ratio of metatarsomere 1: dorsal metatibial spur: ventral metatibial spur: 3.0: 2.0: 1.0.

Abdomen. Ventrites 2–5 with a pair of glabrous regions on anterior portion, longer setae near lateral and posterior margins. Apex of ventrite 5 shallowly concave.

Male terminalia and genitalia. Tergite 8 with apodemes converging posteriorly, fusing into a U-shaped sclerotized cross-piece, plate rectangular with pores on central part, long microtrichia on apical margin and rows of minute microtrichia on lateral parts ( Fig. 95 ). Sternite 8 more or less triangular, weakly sclerotized along anterior margin ( Fig. 96 ). Tergite 9 rounded, with a pair of sclerotized apodemes converging posteriorly, posterior margin with tufts of short microtrichia ( Fig. 97 ). Sternite 9 subtly bilobed, with sclerotized regions curved inwards, posterior part with setae and pores, central part with tufts of minute microtrichia ( Fig. 98 ). Tegmen and penis rather fused, forming a single piece ( Figs. 99, 100 ). Tegmen membranous, slightly asymmetrical, with a medial subapical digitiform outgrowth; microsculpture consisting of pores on the digitiform outgrowth, setae throughout the basal part, and minute denticles along both sides ( Fig. 99 ). Lateroapical parts of aedeagus with elongate denticles ( Fig. 100 ). Penis asymmetrical, foot-shaped, composed of a horizontal basal piece connected to an elongate vertical piece with a long left-handed lateral outgrowth ( Fig. 100 ).

Female genitalia. Anterior part of bursal sclerite with a single tooth and evenly rounded margin, middle part with two teeth ( Figs. 104, 105 ). Prehensor composed of two laminar pieces, one located on the ventral surface and the other on the dorsal surface of the bursa; microsculpture composed of conical microtrichia ( Figs. 103, 106 ).

Sexual dimorphism. Tergite 7 with posterior margin parabolic in females, evenly rounded in males ( Figs. 94 , 102 ), with a fringe of microtrichia along both posterolateral margins in males (absent in females), and with apodemes longer in females than in males ( Figs. 80 , 88 ). Ventrite 5 with posterior concavity deeper in males than in females ( Figs. 93 , 101 ).

Intraspecific variation. The specimens vary in size and in the degree of darkness of the background color of the body, from the holotype and the specimen from “El Destino”, which are almost black ( Figs. 18, 19 ), to the remaining specimens, which are light brown.

Distribution. Argentina: Buenos Aires Province.

Remarks. As stated by Bachmann (2003), the date of collection written on the type’s label differs from the published one (in Brèthes’ original description: “I obtained this species at home, in Villa Urquiza (Buenos Aires) at electric light, March 4th 1922 ”). Ora platensis seems more closely related to O. brevieminentia Libonatti, 2014 since both species have similar general morphology of the aedeagus. The digitiform outgrowth of the tegmen in O. platensis is not narrowed at base as in O. brevieminentia ( Libonatti 2014: figs. 37, 38), the setae over the surface of the tegmen in O. platensis are longer than those in O. brevieminentia , and the penis in O. platensis is broader, with the left-handed protuberance rectangular and longer.

Figures

FIGURES 13 – 25. Ora spp. from Argentina, habitus. 13 – 17, Ora mediolineata (Pic, 1928): 13, holotype, male; 14, female from RN del Iberá (Corrientes); 15 & 16, males from PN Mburucuyá; 17, female from PN Chaco; 18 & 19, O. platensis Brèthes, 1925: 18, holotype, male; 19, male from Reserva El Destino (Buenos Aires); 20 & 21, O. semibrunnea Pic, 1922: 20, holotype, male; 21, female from PN Pre-Delta (Entre Ríos); 22 – 25, O. wagneri (Pic, 1928): 22, holotype, male; 23, male from PN Chaco; 24 & 25, females from Estero Poí (Formosa).

FIGURES 93 – 100. Ora platensis Brèthes, holotype, male. 93, abdomen, ventral aspect; 94, tergite 7; 95, tergite 8; 96, sternite 8; 97, tergite 9; 98, sternite 9; 99, aedeagus, dorsal aspect; 100, aedeagus, ventral aspect.

FIGURES 101 – 106. Ora platensis Brèthes, female. 101, abdomen, ventral aspect; 102, tergite 7; 103, genital organs (except ovaries), dorsal aspect; 104, bursal sclerite, dorsal aspect; 105, bursal sclerite, anterior aspect; 106, prehensor, dorsal aspect. Abbreviations: bsa: bursa, bscl: bursal sclerite, bsl: bursella, gla: accessory gland, prh: prehensor.

FIGURES 79 – 86. Ora mediolineata (Pic), holotype, male. 79, abdomen, ventral aspect; 80, tergite 7; 81, tergite 8; 82, sternite 8; 83, tergite 9; 84, sternite 9; 85, tegmen, dorsal aspect; 86, aedeagus, ventral aspect.

FIGURES 87 – 92. Ora mediolineata (Pic), female. 87, abdomen, ventral aspect; 88, tergite 7; 89, genital organs (except ovaries), dorsal aspect; 90, prehensor, dorsal aspect; 91, bursal sclerite, dorsal aspect; 92, bursal sclerite, anterior aspect. Abbreviations: bsa: bursa, bscl: bursal sclerite, bsl: bursella, gla: accessory gland, prh: prehensor.