Ora semibrunnea Pic, 1922

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 : 89-92

Ora semibrunnea Pic, 1922

( Figs. 20, 21 , 107–124 )

Ora semibrunnea Pic, 1922: 5

Type material. Holotype: ♂ ( MNHN), “Corumba / Matt Grosso” [white label, printed], “ Ora / semibrunnea / Pic” [white label, handwritten by Pic], “ HOLOTYPUS / Ora semibrunnea / Pic, 1922 ” [red label, printed].

Additional material studied. ARGENTINA: 1 ♀ ( MACN), “PIQUETE / 8 – I – 28 / MN” [white label, printed]; 1 ♀ ( MACN), “PIQUETE / 19 – I – 28 / BRIDAROLLI” [white label, printed]; 1 ♀ ( MACN), “ SANTA FE / 22 – II – 28 / REYNA SJ.” [white label, printed]; 2 ♂ and 2 ♀ ( MACN), “ SANTA FE / 23 – II – 28 / REYNA SJ.” [white label, printed]; 1 ♀ ( MACN), " ALTO VERDE S. FE / 12 – II – 29 / BRIDAROLLI S.J. "[white label, printed]; 1 ♀ ( MACN), “ SANTA FE / 15 – II – 31 / BRIDAROLLI S.J. "[white label, printed]; 1 ♂ and ♀ ( MACN), “Rosario”, “ Scirtes / sp.” [white labels, handwritten]; 2 ♂ and 7 ♀ ( MACN), “ROSARIO de / Santa Fe / A.Stévenin” [white label, printed]; 1 ♀ ( MLLC), Entre Ríos, Colón, 29.xii.1991, black light, M. Archangelsky; 4 ♀ (AC), Formosa, Estancia La Marcela, 35 km E. El Colorado 21 dic 2004, 26º 17,35’ S 59º 8,6’ W leg J. Williams/J. E. Barriga; 1 ♀ ( MLLC), PN Mburucuyá, 14.i.2008, light trap, M. C. Michat & P. L. M. Torres; 1 ♀, same data except 16.i.2008; 13 ♂ and 5 ♀, same data except 17.i.2008; 6 ♀ ( MLLC), Santa Fe, Vera, Calchaquí, Reserva Municipal El Cristal, 5& 7.xii.2010, light trap, M. C. Michat; 5 ♂ and 5 ♀ ( MLLC), Entre Ríos, PN Pre-Delta, 19& 21.iii.2012, light trap, M. L. Libonatti; 65 ♂ and 16 ♀ ( MLLC), Corrientes, 28° 3' 39” S 58° 9' 32”, 10.xii.12, light trap, M. C. Michat & P. L. M. Torres; 17 ♂ ( MLLC), Corrientes, PN Mburucuyá, Aº Portillo, 28º 2’ 11” S 58º 6’ 33” W, 11.xii.2012, light trap, M. C. Michat & P. L. M. Torres; 34 ♂ and 33 ♀ ( MLLC), Chaco, PN Chaco, 18.i.2011, light trap, M. C. Michat.

Diagnosis. Body oval, head, antennae, pronotum and scutellar shield brown, elytra yellow, with or without brown spots ( Figs. 20, 21 ); tegmen symmetrical with an apical digitiform outgrowth and the base divided into a pair of apodemes ( Fig. 115 ); penis slightly asymmetrical, rod-shaped, with a pair of apical projections resembling an arrowhead ( Figs. 113, 114, 117, 118 ); anterior part of bursal sclerite semi-oval, with one short tooth, middle part triangular with three short teeth ( Figs. 123, 124 ); prehensor membranous covered with conical microtrichia ( Figs. 121, 122 ).

Redescription. Measurements. Males (n = 10): TL 2.97–3.82 [3.57] (mean 3.52) mm, PL 0.50–0.69 [0.64] (mean 0.62), PW 1.35–1.78 [1.56] (mean 1.58) mm, EL 2.47–3.24 [3,01] (mean 2.95) mm, EW 2.08–2.78 [2.24] (mean 2.42) mm. Females (n = 10): TL 3.67–4.36 (mean 3.93) mm, PL 0.58–0.73 (mean 0.64) mm, PW 1.58–1.97 (mean 1.75) mm, EL 3.01–3.67 (mean 3.32) mm, EW 2.51–3.01 (mean 2.68) mm.

Habitus. Body oval, strongly depressed, maximum width at the basal third of elytra, covered with brownish to yellowish, suberect setae ( Figs. 20, 21 ).

Coloration. Head, pronotum, scutellar shield, antennae, thoracic pleura, thoracic ventrites and legs (except the yellow tibiae and basal third of metafemora) brown. Elytra yellow, with a row of brown minute spots parallel to the suture, extending 4/5 of the elytral length. Abdomen brown laterally and yellowish medially, ventrites 2–5 with a pair of lateral yellow oval areas.

Head. Wide, approximately 1.9x wider than interocular space, clypeal surface flat; punctation very fine. Antennae filiform, with apical margins of antennomeres 4–10 projected anteriorly, approximate ratio of antennomeres: 1.8: 1.1: 1.0: 1.8: 1.8: 2.0: 2.0: 1.8: 1.9: 1.9: 2.0, approximate L/W ratios of antennomeres: 1.4, 1.1, 1.3, 1.8, 1.6, 1.8, 1.6, 1.4, 1.9, 1.9, 2.7. Mandibles with obtuse apex.

Thorax. Pronotum approximately 2.4x wider than long, anterolateral angles sharply projecting anteriorly, lateral margins almost straight; punctation on pronotum and scutellar shield similar to that on head. Elytra very depressed anterolaterally, humerus well marked, lateral margins rounded; punctation composed of fine (somewhat coarser than that on head, pronotum and scutellar shield) punctures separated by 1– 2 x diameter, with intermixed coarser punctures 2x the size and separated by 4– 6 x diameter; the fine punctures bearing shorter and more horizontal setae, the coarse punctures bearing longer and more erect setae; elytra with a row of submarginal punctures parallel to elytral suture. Mesoventral process elongate, very thin, lateral margins strongly converging posteriorly, with acute apex. Approximate length ratio of metatarsomere 1: dorsal metatibial spur: ventral metatibial spur: 3.3: 2.6: 1.0.

Abdomen. Completely covered with short yellowish setae except for the glabrous posterior margin of ventrite 1 and the pair of glabrous lateral regions on ventrites 2–5, with dark curved setae occuring on the lateral and posterior margins of ventrites 2–5 ( Figs. 107, 108 ).

Male terminalia and genitalia. Tergite 8 with apodemes converging posteriorly, connected by two sclerotized cross-pieces, plate rectangular with pores and setae on central part and long microtrichia on apical margin ( Fig. 110 ). Sternite 8 not distinct. Tergite 9 with a pair of sclerotized apodemes converging posteriorly, plate squareshaped with pores on central part and tufts of microtrichia on posterior margin ( Fig. 111 ). Sternite 9 apically bilobed, with sclerotized regions curved inwards, posterior part with setae and pores ( Fig. 112 ). Tegmen symmetrical, with an apical digitiform outgrowth and a pair of apodemes at base, microsculpture composed of pores on the digitiform outgrowth and long setae on middle to apical surface ( Figs. 113, 115 ). Penis symmetrical, rod-shaped, broadened and bent at base, with a pair of apical projections together forming an arrowhead ( Figs. 113, 114, 117, 118 ).

Female genitalia. Anterior part of bursal sclerite laminar, straight, semioval, with a single minute tooth near the posterior margin; middle part triangular with three minute teeth ( Figs. 123, 124 ). Prehensor membranous covered with conical microtrichia ( Figs. 121, 122 ).

Sexual dimorphism. Most females with numerous coalescent brown spots on elytra ( Fig. 21 ). Tergite 7 with longer apodemes in females than in males, posterior margin subtrapezoidal in females and rounded in males ( Figs. 109 , 120 ). Ventrite 5 with a deep concavity in males, truncate and lacking concavity in females ( Figs. 107, 108 , 119 ).

Intraspecific variation. Specimens vary in the presence/absence and in the degree of coalescence of brown spots on elytra. Most males and a few females bear uniformly yellow coloration on elytra as does the holotype ( Fig. 20 ). Most females and a few males exhibit small brown spots on elytra ( Fig. 21 ). Some variation in male and female genitalia was observed. The base of the penis may be more abruptly curved as in the holotype and some specimens from Santa Fe and Chaco Provinces ( Fig. 113 ), or more gradually curved as in some specimens from Santa Fe, Corrientes and Entre Ríos Provinces ( Fig. 118 ). In most females there is a U-shaped notch on the anterior margin of the bursal sclerite ( Fig. 124 ), in a few females the anterior margin is evenly rounded, lacking a notch, and there is a non-sclerotized region (resembling a hole) nearby ( Fig. 123 ), and in a few females the anterior part of the bursal sclerite exhibits both a notch and a hole. Intraspecific variation in female genitalia of Scirtidae has already been reported for Scirtes caledonicus Bourgeois, 1884 , in which remarkable differences in the morphology of the bursal sclerite and prehensor were noticed ( Ruta 2014). A more comprehensive study, including more specimens from Argentina and Brazil, is needed to verify or reject the hypotheses of intraspecific/interspecific variation.

Distribution. Brazil. Argentina: Chaco, Corrientes, Entre Ríos, Formosa and Santa Fe Provinces.

Remarks. As Champion (1897) first noticed, several Neotropical species of Ora are characterized by the broadly oval, depressed body, and the elytra more or less explanate at the sides, with intermixed coarser punctures bearing longer setae. At the moment, the species known to bear those features are: O. discoidea , O. marmorata , O. mixta , O. obliqua , O. bivittata , O. bruchi , O. depressa , O. megadepressa and O. semibrunnea . Coloration of body, and male and female genitalia make O. semibrunnea quite distinct among those species.

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 107 – 118. Ora semibrunnea Pic, male. 107 – 116, holotype: 107, abdomen, ventral aspect; 108, ventrite 5; 109, tergite 7; 110, tergite 8; 111, tergite 9; 112; sternite 9; 113, aedeagus, dorsal aspect; 114, apical portion of aedeagus, dorsal aspect; 115, tegmen, dorsal aspect; 116, posterolateral microsculpture of tegmen; 117 & 118, male from PN Mburucuyá: 117, penis, ventral aspect; 118, penis, left aspect.

FIGURES 119 – 124. Ora semibrunnea Pic, female. 119, abdomen, ventral aspect; 120, tergite 7; 121 – 123, female from Santa Fe: 121, genital organs (except ovaries), dorsal aspect; 122, prehensor; 123, bursal sclerite, anterior aspect; 124, female from Santa Fe, bursal sclerite, anterior aspect. Abbreviations: bsa: bursa, bscl: bursal sclerite, bsl: bursella, gla: accessory gland, prh: prehensor.