Ora megadepressa, Libonatti, María Laura, 2014

Libonatti, María Laura, 2014, A revision of the genus Ora Clark, 1865 (Coleoptera: Scirtidae) in Argentina (part I) — descriptions of new species, Zootaxa 3884 (1), pp. 27-44 : 36-44

Ora megadepressa sp. n.

Type material. Holotype: ♂ ( MACN), “ ARGENTINA: Corrientes / 28º 3’ 39” S 58º 9’ 32” W / 10.xii.2012, light trap / MC Michat & PLM Torres” [white label, printed], “ HOLOTYPUS / Ora megadepressa / Libonatti, 2014” [red label, printed]. Paratypes (all bearing same locality label as holotype and a yellow, printed label “ PARATYPUS / Ora megadepressa / Libonatti, 2014”): 2 ♂ and 1 ♀ ( MACN), 2 ♂ and 1 ♀ (NHM).

Diagnosis. Body broadly oval ( Figs. 23, 24 ), hypomera and epipleura disctinctly broad; left-handed surface of the tegmen spiny ( Figs. 55, 57 ), penis rod-shaped, straight in its major part, its base abruptly bent to the right hand side and its subapical projection right-handed and long ( Fig. 54 ); bursal sclerite with markedly emarginate margin ( Fig. 62 ), prehensor membranous, composed of numerous folds ( Fig. 63 ).

Description. Measurements. Males (n = 5): TL 4.33–4.63 (mean 4.48) mm, PL 0.73–0.78 (mean 0.75) mm, PW 2.24–2.39 (mean 2.31) mm, EL 3.90–4.09 (mean 3.95) mm, EW 3.26–3.46 (mean 3.39) mm. Females (n = 2): TL 4.43 mm, PL 0.71–0.73 (mean 0.72) mm, PW 2.14–2.29 (mean 2.22) mm, EL 3.80 mm, EW 3.51 mm.

Habitus. Broadly oval, strongly dorsoventrally compresed, maximum width at basal third of elytra, closely covered with yellowish-brownish setae ( Figs. 23, 24 ).

Coloration. Body yellow, head and pronotum somewhat brownish, elytra with many pale marks and a row of minute brown spots parallel to the elytral suture, antennae brownish, hind femur reddish.

Head. Wide, approximately 1.9x wider than interocular space, clypeal surface flat; punctation very fine, punctures separated by 2.0x diameter. Antennae subtly serrate, with apical margins of antennomeres 4–10 slightly projected anteriorly, approximate ratio of antennomeres: 1.4: 1.1: 1.0: 2.0: 2.0: 1.8: 1.8: 1.8: 1.6: 1.6: 1.8, approximate L/W ratios of antennomeres: 1.4, 1.4, 1.4, 2.5, 2.5, 2.3, 2.3, 2.3, 2.0, 2.0, 2.3. Mandibles with obtuse apex ( Fig. 4 ).

Thorax. Pronotum approximately 3.3x wider than long, anterolateral angles sharply projecting anteriorly, lateral margins straight; punctation of pronotum and scutellum similar to that on head. Elytra lacking costulae, very depressed anterolaterally, humerus well marked, lateral margins fairly rounded, acuminate posteriorly; punctation composed of very fine puctures separated by 2.0–3.0x diameter, intermixed with coarse punctures twice the size and separated by 5.0–6.0x diameter; the fine punctures bearing shorter and more horizontal setae, the coarse punctures bearing longer and more erect setae, dark or light depending on the angle of light direction; elytra with a row of submarginal punctures parallel to elytral suture. Hypomera and epipleura very broad. Mesoventral process elongate, thin, with acute apex ( Fig. 12 ). Approximate length ratio of metatarsomere 1: dorsal metatibial spur: ventral metatibial spur: 3.5: 3.1: 1.0.

Abdomen. Lateral and posterior parts of each abdominal ventrite covered with long setae, rest of the abdominal surface covered with short setae, except for the glabrous regions. Apex of ventrite 5 triangularly concave ( Figs. 49 , 58 ).

Male terminalia and genitalia. Tergite 8 with sclerotized apodemes converging posteriorly, posterior margin arcuate, with setae, pores and short microtrichia on central part and long microtrichia on apical margin ( Fig. 51 ). Sternite 8 not distinct. Tergite 9 rounded, with a pair of sclerotized apodemes converging posteriorly, posterior margin with pores, setae and tufts of short microtrichia ( Fig. 52 ). Sternite 9 apically bilobed, with a pair of sclerotized strips curved on inner side, posterior part with setae and pores ( Fig. 53 ). Tegmen membranous, asymmetrical, with an apical digitiform outgrowth; microsculpture consisting of pores on the digitiform outgrowth, pores and minute setae throughout the basal part, and a spiny region on the left-handed side ( Figs. 54–57 ). Penis asymmetrical, rod-shaped, major part straight, base abruptly curved to the right-handed side, subapical triangular process projected to the right-handed side ( Fig. 54 ).

Female genitalia. Bursal sclerite: anterior part with one small spine and markedly emarginate margin, middle part with a pair of narrow spines ( Figs. 60–62 ). Prehensor membranous with numerous folds ( Figs. 60, 63 ).

Sexual dimorphism. Female with brown spots on head and pronotum, and with two groupings of short dark setae on elytra: one occupying an elongate portion of elytral surface situated at middle of elytral length adjacent to the elytral suture, and the other covering a rounded portion of the surface, approximately at the same level of the former one but more external ( Figs. 24, 25 ). Tergite 7 more projected medially in females than in males ( Figs. 50 , 59 ). Ventrite 5 with posterior concavity much deeper in males than in females ( Figs. 49 , 58 ).

Etymology. This species is named megadepressa since it is very similar in habitus and morphology of male genitalia to Ora depressa ( Fabricius, 1801) but it is larger.

Remarks. The broadly oval, depressed body shape and the intermixed coarser punctures on elytra are shared with O. discoidea Champion (from Mexico, Guatemala and Honduras), O. marmorata Champion (from Panama, Trinidad and Brazil), O. mixta Champion (from Guatemala), O. obliqua Champion (from Mexico and Guatemala) ( Champion 1897), O. bivittata Pic (from Brazil), O. semibrunnea Pic (from Brazil), O. bruchi Pic (Libonatti, unpublished results) and O. depressa (Fabricius) (from South America) (Ruta, personal communication 2014). Ora megadepressa sp. n. differs from the other Neotropical species in its smaller TL/EW ratio and in the body color ( O. discoidea , O. obliqua and O. bivittata bear a brown vitta on each elytron, O. marmorata and O. bruchi exhibit brown maculated elytra, and O. semibrunnea has dark brown head and pronotum). The new species seems most closely related to O. depressa , recently redescribed by Ruta (2013). Both species share a rod-shaped penis with a subapical lateral projection. Differences between both species are summarized in Table 1 .

Type material. Holotype: ♂ ( MACN), “ ARGENTINA: Buenos Aires / Reserva El Destino / 26.xi.2012 / vegetated ditch / beating riparian trees / ML Libonatti” [white label, printed], “ HOLOTYPUS / Ora sigmoidea / Libonatti, 2014” [red label, printed]. Paratypes (all bearing yellow, printed label “ PARATYPUS / Ora sigmoidea / Libonatti, 2014”): 1 ♀ ( MACN), same locality label as holotype; 2 ♂ and 11 ♀ ( MACN), same locality label as holotype except 25.xi.2012; 1 ♂ and 1 ♀ (NHN), same locality label as holotype except 21.xi.2011.

Additional material studied. 1 ♀ (BR), “R EP ARGENTINA / Prov. Buenos Aires / XI. 1894 / C. Bruch” [white label, printed], “ Scirtes / brevenotatus / var. Pic” [white label, handwritten by Bruch], “ Scirtes / brevenotatus / var. Pic” [white label, handwritten by Pic]; 1 ♀ (BR): “R EP ARGENTINA / Prov. Buenos Aires / 189 / C. Bruch” [white label, printed]; 1 ♀ (BR): “R EP ARGENTINA / Prov. Buenos Aires / 190 / C. Bruch” [white label, printed]; 1 ♂ ( MACN), “Delta del Paraná - Río / Paraná de las Palmas / Estac. Exp. Agropec. INTA / Leg. Oliva A la luz” [white label, handwritten]; 1 ♂ ( MACN), “Delta del Paraná – Río / Sarmiento Leg. Oliva” [white label, handwritten]; 1 ♂ ( MACN), “Delta del Paraná - Río / Sarmiento / II.1976 / Leg. Oliva” [white label, handwritten]; 2 ♂ and 1 ♀ ( MACN), “Delta del Paraná - Río / Sarmiento / I.1977 / Leg. Oliva” [white label, handwritten].

Diagnosis. Size relatively large, body elliptical, broad, elytral color pattern composed of five basal pale spots, pale vittae and a black trifurcate subapical mark, elytra with four costulae ( Figs. 26, 27, 29 ); tegmen with minute setae ( Fig. 73 ), dorsal piece of penis laminar, with apical part and lateral margins spiny, apex obliquely truncate, ventral piece of penis sigmoid ( Fig. 72 ); anterior margin of bursal sclerite with a semicircular emargination ( Fig. 79 ), prehensor boxing-glove-shaped, with right-handed anterior part spiny ( Fig. 80 ).

Description. Measurements. Males (n = 9): TL 4.92–5.55 (mean 5.29) mm, PL 0.78–0.97 (mean 0.90) mm, PW 2.00–2.29 (mean 2.10) mm, EL 4.14–4.92 (mean 4.51) mm, EW 2.92–3.56 (mean 3.32) mm. Females (n = 17): TL 4.87–6.02 (mean 5.50) mm, PL 0.78–1.02 (mean 0.92) mm, PW 2.00–2.53 (mean 2.28) mm, EL 4.14–5.65 (mean 4.82) mm, EW 2.98–3.70 (mean 3.40) mm.

Habitus. Elliptical, broad, depressed, maximum width at middle of elytra, closely covered with yellowish setae ( Figs. 26, 27, 29 ).

Coloration. Head brown with a frontal V-shaped reddish testaceous mark between the eyes, mouthparts and antennomeres 1–2 testaceous, antennomeres 3–11 brownish testaceous, clypeus and labrum reddish testaceous. Pronotum brown, margins and a pair of central spots reddish testaceous, anterior and posterior margins with a medial triangular reddish testaceous mark extending a third to a quarter of the pronotal length. Scutellum brown with reddish testaceous margins. Elytra brown, basal quarter of elytra having at most five pale testaceous spots: one inverted L-shaped spot adjacent to the scutellum with its base along the anterior elytral margin, two contiguous spots located in a perpendicular line to the lateral margin of scutellum, one elongate spot on the humerus and a transversal spot on the lateral margin behind the humerus, second quarter of elytra light brown, with 2–3 testaceous stripes, posterior half of elytra light brown with an apical trifurcate black mark. Ventral surface brownish testaceous except for the brown apex of the posterior femur and tibia, and a pair of brown marks on the anterior margin of ventrites 2–5.

Head. Rather wide, approximately 2.0x wider than interocular space, clypeal surface convex; punctation fine, dense, punctures separated by 0.5x diameter. Antennae filiform, with apical margins of antennomeres 4–10 not projected anteriorly, approximate ratio of antennomeres: 2.0: 1.0: 1.6: 2.6: 2.6: 2.4: 2.4: 2.2: 2.2: 2.2: 2.2, approximate L/W ratios of antennomeres: 1.7, 1.3, 2.7, 4.3, 4.3, 4.0, 4.0, 3.7, 3.7, 3.7, 3.7. Mandibles with acute apex ( Figs. 5, 6 ).

Thorax. Pronotum approximately 2.4x wider than long, anterolateral angles sharply projecting anteriorly, lateral margins rounded; punctation coarser than on head, punctures separated by 0.5–1.0x diameter. Scutellum with punctation somewhat coarser and more dispersed than on pronotum. Elytra depressed anterolaterally, humerus well marked, lateral margins rounded, with four costulae: the first (inner) costula beginning at the outer adscutellar testaceous spot, the second costula beginning at the apex of the inverted-L-shaped spot, the third costula beginning at the humerus and the fourth (outer) costula beginning behind the testaceous transverse spot, all of them ending at the apical dark spot; punctation uniform, coarser than on head, pronotum and scutellum, punctures separated by 1.0–2.0x diameter. Mesoventral process elongate, thin, with markedly notched apex ( Fig. 15 ). Approximate length ratio of metatarsomere 1: dorsal metatibial spur: ventral metatibial spur: 3.1: 2.6: 1.0.

Abdomen. Completely covered with short yellowish setae except for a pair of glabrous regions on ventrites 2–5, coincident with the brown marks. Apex of ventrite 5 triangularly concave ( Figs. 64 , 75 ).

Male terminalia and genitalia. Tergite 8 with sclerotized apodemes converging posteriorly, with a sclerotized cross-piece, posterior margin arcuate, with setae on central part, short microtrichia on lateral parts and long microtrichia on apical margin ( Figs. 66, 67 ). Sternite 8 more or less trapezoidal, weakly sclerotized, more heavily sclerotized along anterior margin ( Fig. 68 ). Tergite 9 more or less square-shaped, with a pair of sclerotized apodemes converging posteriorly, posterior margin rounded, with a row of microtrichia ( Fig. 69 ). Sternite 9 elongate, apically bilobed, with a pair of sclerotized apodemes more or less parallel-sided, almost meeting posteriorly, posterior margin with setae, central part with tufts of minute microtrichia ( Figs. 70, 71 ). Tegmen membranous, slightly asymmetrical, with an apical left-handed digitiform outgrowth; microsculpture consisting of pores on the digitiform outgrowth, pores and minute setae throughout the medial part, and scale-like rows of minute microtrichia on the posterolateral part ( Figs. 73, 74 ). Penis strongly asymmetrical, composed of two pieces: dorsal piece with a long and broad laminar appendix, with lateral margins more or less parallel-sided at base, abruptly and asymmetrically broadened at middle, then converging posteriorly to an obliquely truncate tip, surface near the tip spiny, left margin serrate throughout, right margin serrate along the apical two-thirds, ventral surface furrowed, dorsal surface crossed by two narrow, posteriorly pointed, strongly sclerotized strips; ventral piece sigmoid, ending in a strongly sclerotized, narrow, uniformly curved appendix ( Fig. 72 ).

Female genitalia. Bursal sclerite: anterior part with one spine and arcuately emarginate margin, middle part with a pair of anterior relatively long spines with one minute spine in the middle and one posterior spine ( Figs.

77–79). Prehensor composed of one dorsal boxing-glove-shaped part with the right-handed basal surface covered with minute spines, and one ventral laminar oblong part ( Figs. 77, 80 ).

Sexual dimorphism. Female elytra with two foveae near the apex ( Figs. 27, 28 ): one short longitudinal depression adjacent to the suture and one rounded depression located externally to the former, both closely covered with fine setae; male lacking elytral foveae. Tergite 7 with a fringe of microtrichia along both lateral parts of the posterior margin in males (absent in females), with longer apodemes in females than in males, posterior margin arcuately projected in females and triangularly projected in males ( Figs. 65 , 76 ).

Intraspecific variation. Specimens vary in size and in the degree of maculation on elytra. Some specimens are lighter in color and bear four testaceous stripes on each elytron, each located on a costula. Some females have the elytra almost completely brown and the apical dark mark reduced ( Fig. 29 ).

Etymology. This species is named sigmoidea in reference to the resemblance of the ventral part of the penis to the Greek letter sigma.

Natural history. Adults were collected by beating riparian trees (mainly Acacia sp.) near a small swamp containing fallen leaves in the bottom.

Remarks. The broad elliptical body, the basal pale maculation and the costulae of elytra are features shared with O. brevenotata ( Pic, 1915) (from Brazil) ( Fig. 81 ). Pic apparently noticed the affinities between these species since the material in BR is labeled as a “variety” of O. brevenotata . Furthermore, the general shape of the aedeagus is similar in both species ( Figs. 82–84 ), and also in O. texana Champion, 1897 (from southern USA) ( Nyholm 1972). However, differences between the aedeagi of the three species are notable and are summarized in Table 2 .

Figures

FIGURES 22 – 29. New species of Ora from Argentina, habitus. 22, Ora brevieminentia sp. n., male holotype; 23 – 25, O. megadepressa sp. n.: 23, male paratype; 24, female paratype; 25, detail of female elytron in rectangular area indicated on habitus; 26 – 29, O. sigmoidea sp. n.: 26, male holotype; 27, female paratype; 28, detail of female elytron in rectangular area indicated on habitus; 29, female paratype.

FIGURES 49 – 57. Ora megadepressa sp. n., male holotype. 49, abdomen, ventral aspect; 50, tergite 7; 51, tergite 8; 52, tergite 9; 53, sternite 9; 54, aedeagus, dorsal aspect; 55, tegmen; 56, apical microsculpture of tegmen; 57, lateral microsculpture of tegmen.

FIGURES 58 – 63. Ora megadepressa sp. n., female paratype. 58, abdomen, ventral aspect; 59, tergite 7; 60, genital organs (except ovaries), dorsal aspect; 61, bursal sclerite, dorsal aspect; 62, bursal sclerite, anterior aspect; 63, prehensor, dorsal aspect.

FIGURES 1 – 9. Argentine Ora spp., head and mouthparts morphology. 1, O. brevieminentia sp. n., head and prothorax, dorsal aspect; 2 – 4, O. megadepressa sp. n.: 2, head, ventral aspect; 3, labrum, dorsal aspect; 4, left mandible, dorsal aspect; 5 – 9, O. sigmoidea sp. n.: 5, left mandible, dorsal aspect; 6, left mandible, ventral aspect; 7, left maxilla, ventral aspect; 8, setae on apical part of galea; 9, labium, ventral aspect. Abbreviations: gus: gular suture, sgr: subgenal ridge.

FIGURES 10 – 16. Argentine Ora spp., thorax morphology. 10 – 13, Ora megadepressa sp. n.: 10, prothorax, ventral aspect; 11, prosternum, lateroventral aspect; 12, mesoventrite; 13, metathorax, ventral aspect; 14, O. brevieminentia sp. n., mesoventrite; 15 – 16: O. sigmoidea sp. n.: 15, mesoventrite; 16, right metathoracic wing, dorsal aspect.

FIGURES 64 – 74. Ora sigmoidea sp. n., male holotype. 64, abdomen, ventral aspect; 65, tergite 7; 66, tergite 8; 67, lateral microsculpture of tergite 7; 68, sternite 8; 69, tergite 9; 70, sternite 9; 71, medial microsculpture of sternite 9; 72, aedeagus, ventral aspect; 73, tegmen; 74, posterolateral microsculpture of tegmen.

FIGURES 75 – 80. Ora sigmoidea sp. n., female paratype. 75, abdomen, ventral aspect; 76, tergite 7; 77, genital organs (except ovaries), dorsal aspect; 78, bursal sclerite, dorsal aspect; 79, bursal sclerite, anterior aspect; 80, prehensor, dorsal aspect. Abbreviations: bsa: bursa, bscl: bursal sclerite, bsl: bursella, gla: accessory gland, prh: prehensor.

FIGURES 81 – 84. Ora brevenotata (Pic), holotype: 81, habitus, dorsal aspect; 82, aedeagus, ventral aspect; 83, spiny part of penis; 84, tegmen.

Tables

TABLE 1. Comparison of Ora megadepressa sp. n. and O. depressa Fabricius.

	Ora megadepressa (Figs. 54–57)	Ora depressa (see Ruta 2013: Figs. 3A, 3B, 4)
Body shape	Broader, smaller ratio TL/EW (mean: 1.13 for male, 1.17 for female); elytra acuminate posteriorly	Narrower, higher ratio TL/EW (mean: 1.41 for male, female unknown); elytra not acuminate posteriorly
Color of elytra	With pale marks	Uniformly yellow
Tegmen	Left-handed side with a spiny surface; basal part of digitiform outgrowth little narrowed	Lacking spiny surface; basal part of digitiform outgrowth strongly narrowed
Penis	Straight in most of its length, base abruptly curved to the right-handed side; subapical process longer and projected to the right-handed side	Evenly curved along its length; subapical process shorter and projected to the left-handed side
Ora sigmoidea	sp. n.

TABLE 2. Comparison of Ora sigmoidea sp. n., O. brevenotata (Pic) and O. texana Champion.

	Ora sigmoidea (Figs. 72, 73)	Ora brevenotata (Figs. 82–84)	Ora texana (see Nyholm 1972: Fig. 4A)
Tegmen	Digitiform outgrowth less protruding and more narrowed at base; surface covered with short setae	Digitiform outgrowth more protruding and less narrowed at base; surface covered with long setae	Digitiform outgrowth more protruding and less narrowed at base; setae unknown
Dorsal piece of penis	Laminar, only lateral margins and apical part spiny, much more broadened than in O. texana , apex obliquely truncate, without lateral acute projection	Not laminar, only the medial region spiny, acutely pointed posteriorly and with a lateral acute projection	Laminar, only lateral margins and apical part spiny, much less broadened than in O. sigmoidea , apex acutely rounded, without lateral acute projection
Ventral piece of penis	S-shaped in ventral aspect, much more curved than in O. texana , apical part not abruptly bent	S-shaped in dorsal aspect, apical part abruptly bent	S-shaped in ventral aspect, much less curved than in O. sigmoidea , apical part not abruptly bent