Diestostemma bituberculatum ( Signoret, 1855 )

Pinto, Ângelo Parise, Mejdalani, Gabriel & Takiya, Daniela Maeda, 2017, Unraveling the white-clothed Diestostemma Amyot & Serville: a taxonomic revision of the American sharpshooters of the D. bituberculatum complex (Hemiptera: Cicadellidae), Zootaxa 4281 (1), pp. 135-164 : 144-145

Diestostemma bituberculatum ( Signoret, 1855)

LSID http://zoobank.org/urn:lsid:zoobank.org:act:25310920-DBED-4E7C-8BDE-8F4054B0FD38 ( Figures 3–4 , 13–14 , 17–18 , 27–28 , 39–40 , 48–49 , 59–62 , 75–77 , 88 , 93 )

Tettigonia bituberculata Signoret, 1855: 528 , pl. 21, fig. 19 (description of male and female syntypes from Rio-Negro [BRAZIL. Amazonas State] in NHMW; comparison with D. albipennis , illustration of habitus of the male [?] in dorsal view);— Kirkaldy (1907: 87, as types species of Leucopepla );— Young & Beier (1964: 567, designation of male lectotype);— Evans (1947: 169, mention as type species of Leucopepla );— Metcalf (1965: 469, catalog, as type species of Leucopepla );— Young (1968: 30, mention as type species of Leucopepla );

Leucopepla bituberculata ( Signoret, 1855) :— Kirkaldy (1907: 12, 87, comb. nov. as type species of Leucopepla );— Melichar (1924: 211, key, redescription of male and female, comparison with D. atropunctulatum );— Metcalf (1965: 470, catalog);— Schmidt (1928: 37, mention as type species of Leucopepla , comparison with D. rubriventris );

Diestostemma bituberculata ( Signoret, 1855) :— Walker (1858: 241, comb. nov., catalog);— McKamey (2007: 287, catalog, records from Guyana, French Guiana, Brazil, Argentina, and Uruguay based on Metcalf 1965 and Young 1968);— Paradell et al. (2012: 6, question the occurrence in Argentina);

Diestostemma bituberculatum ( Signoret, 1855) :— Schmidt (1910: 34, 49–50, key, reproduction of the original description);— Young (1968: 32, 35, 38, figs. 21e–f, i, key, illustrations of female sternite VII in ventral view, connective and stylus in dorsal view and aedeagus in lateral view, records from Guyana, French Guiana, and Brazil);— Zanol & Menezes (1982: 16, record from Brazil).

Material examined (3 ♂, 3 ♀). FRENCH GUIANA. [Cayenne Arrondissement]: 1 ♂, 1 ♀, [ Régina commune], 23 km SE Roura on Kew Rd, MV Light (04°34’8.10”N, 52°11’09”W, 238 m a.s.l.), 16–17.IV.2007, D.G. Hall & J.E. Eger leg. ( FSCA) ; 2 ♂, [Roura commune], Kaw Mountain Reserve, unpaved logging road, nr. Amazone Lodge, MV Lights and inspection of vegetation (04°32’57.8”N, 52°12’49.7”W, 287 m a.s.l.), II.2005, J.R. Cryan & J.M. Urban leg. ( INHS) ; [Saint-Laurent-du-Maroni Arrondissement]: 2 ♀, [Saül commune], PM-APL, Bélvédère de Saül , Malaise (03°37’22”N, 53°12’57”W, 308 m a.s.l.), 09.IX.2010, SEAG leg . (DZRJ).

Type repository. Lectotype male by subsequent designation ( Young & Nast 1963) and paralectotype female in NHMW, examined by photos (©2016, Natural History Museum Vienna, Hemiptera Image Collection / H. Bruckner).

Measurements (mm, n = 5). Females are larger than males; all upper bounds of intervals correspond to females. Total length (from anterior of head to tip of forewings) 19.2–21.9; crown length 2.4–2.9; interocular distance 2.4–2.9; transocular distance 3.8–4.3; distance between compound eye and mesal line 1.3–1.5; distance between ocellus and mesal line 0.9–1.4; pronotal disc maximum width 5.2–6.0; pronotal disc maximum length 3.6– 4.1; forewing length 15.3–17.9; metathoracic femur length 3.7–4.6; metathoracic tibia length 7.1–8.4.

Diagnosis. A large, dorsolaterally white and ventrally realgar colored Diestostemma , with two pronotal humps and small dark areas on the forewing. Males and females of D. bituberculatum can be distinguished from almost all species, except D. cavichiolii sp. nov. and D. rubriventris , by the pronotal disc virtually lacking dark areas. Diestostemma bituberculatum can be distinguished from D. rubriventris by the H-shaped distal SDV of the forewing ( Figs. 48–49 ; distal SDV large and round in D. rubriventris , Figs. 54–55 ) and from D. cavichiolii sp. nov. by its larger size with total length 19.2–21.9 mm (18.3–20.8 mm in D. cavichiolii sp. nov.), realgar colored venter of abdomen ( Figs. 39–40 ; yellowish-brown in D. cavichiolii sp. nov.), and pronotal humps strongly projected ( Figs. 3–4 , 18 ; distinctly less projected in D. cavichiolii sp. nov., Figs. 5–6 , 20 ).

Males can be distinguished from other species of the D. bituberculatum complex by the abruptly anteriorly curved aedeagal process, forming an angle of about 90° in lateral view, bifurcated into a pair of thin, slightly flattened rami in lateral view ( Figs. 75–77 ; aedeagal process gently curved forming obtuse angle, bifurcated into a pair of expanded or slightly expanded flattened rami in the remaining species, Figs. 72–74, 78–86 ).

Females have the posterior margin of sternite VII trilobed, with mesal lobe strongly projected, extending distally farther than lateral lobes ( Fig. 88 ), which allows separating D. bituberculatum from all species of this complex except D. albinoi sp. nov. Distinguishing female characters between these two species are given under the diagnosis of the latter species.

Distribution. Recorded from the Amazonia Domain in Guyana, French Guiana, and Amazonas State in Brazil. Its occurrence in southern South American countries Uruguay and Argentina, as cited by Metcalf (1965), is a mistake (see below and in Paradell et al. 2012). Very likely, it is an exclusively tropical South American species occurring at the Amazonian formations of the Brazilian subregion ( Fig. 93 ).

Etymology. The specific name bituberculatum is a declinable adjective. This compound word is formed by the Latin numeral prefix bi- (two, double) plus tuberculum (stem tubercul -; noun n., 2nd decl.; small swelling, protuberance) plus the adjectival suffix – atus –a –um (equipped with) in its neuter form. This name, meaning ‘equipped with two bumps or protuberances,’ refers to the two pronotal humps observed in all species of the D. bituberculatum complex and some species of other groups of Diestostemma (e.g., D. nervosum group). Given that this specific name is an adjective and the genus name is neuter in gender, in agreement with article 31.2 of the International Code of Zoological Nomenclature (ICZN 1999) they must agree in gender, thus the correct spelling is D. bituberculatum , which was firstly adopted by Schmidt (1910). McKamey (2007, p. 287) incorrectly catalogued D. bituberculata following his assumption of an “implicit” new combination by Young (1968, p. 32) of the transfer of Tettigonia bituberculata Signoret, 1855 to Diestostemma . This mistake possibly occurred because Young (1968) only presented specific names and not the full combination with the genus-group name or because he did not use the expression “new combination” for this species. However, McKamey (2007) overlooked the key and figure captions in Young’s (1968, p. 35, 38) monograph, where he clearly stated the combination “ D [iestostemma] bituberculatum ”. Nevertheless, Walker (1858, p. 241) had already previously combined this specific name with Diestostemma .

Remarks. This species was originally described from “Rio-Negro” ( Figs. 13–14 ), which researchers would now identify with little doubt as the large river in the Brazilian Amazonia. Metcalf (1965) and Young (1968) cited its occurrence for Argentina and Uruguay, very likely based on the same locality of Rio Negro. Papavero (1994, p. 113) mentioned a longtime confusion among two homonymous Rio Negro localities in South America, one at the Amazonian Basin and the other referring to Rio Negro Province of southern Argentina. Rio Negro is also an important river crossing Uruguay . All of this would lead both Metcalf (1965) and Young (1968) to consider its occurrence in the Pampean biogeographical province and Andean Region either in Argentina or Uruguay . However, there are no records of specimens of this group ( D. bituberculatum complex) outside the Amazonian Basin. The southernmost record for D. bituberculatum is located at 03°08’S, and recently records from Argentina were considered doubtful ( Paradell et al. 2012). Hence , D. bituberculatum must be removed from the checklists of these countries.

Since the milestone monograph by Young (1968), structures of the male genitalia are used as a source of taxonomic characters for Diestostemma , including the shape of the arms of the connective. However, we observed strong variation in the few males of D. bituberculatum examined ( Figs. 61–62 ), suggesting that other characters should be used in combination with the male genitalia to confirm species identifications.

Figures

FIGURE 93. Map of northern South America with distribution records of the Diestostemma bituberculatum species complex. Colored areas correspond to the Neotropical regionalization of biotic elements by Morrone (2014). Abbreviations: OR, Orellana Province, Ecuador; MDD, Madre de Dios Department, Peru; AM, Amazonas, RO, Rondônia, and MT, Mato Grosso, for Brazilian States.

FIGURES 1 – 12. Head and prothorax of species of the Diestostemma bituberculatum complex in anterior view. 1 – 2. Male holotype and female paratype of D. albinoi sp. nov. (Ecuador, Orellana Province, EPNC, USNM); 3 – 4. Male and female of D. bituberculatum (Signoret, 1855) (French Guiana, Cayenne Arrondissement, INHS, DZRJ); 5 – 6. Male holotype and female paratype of D. cavichiolii sp. nov. (Brazil, Mato Grosso State, DZUP); 7 – 8. Male holotype and female paratype of D. gervasioi sp. nov. (Ecuador, Orellana Province, EPNC, USNM); 9 – 10. Male holotype and female paratype of D. olivia sp. nov. (Ecuador, Orellana Province, EPNC, USNM); 11 – 12. Male and female of D. reticulatum (Melichar, 1924) (Peru, Cusco Department, DZRJ). Scale bars = 2 mm.

FIGURES 13 – 14. Habitus and corresponding labels of the type series of Tettigonia bituberculata Signoret, 1855 (Brazil, AM: Rio Negro, © 2016, Natural History Museum Vienna, Hemiptera Image Collection / H. Bruckner), currently Diestostemma bituberculatum (Signoret, 1855), in dorsal and ventral views. 13. Lectotype male; 14. Paralectotype female.

FIGURES 15 – 24. Male habitus of species of the Diestostemma bituberculatum complex in dorsal (15, 17, 19, 21, 23) and lateral (16, 18, 20, 22, 24) views. 15 – 16. Holotype of D. albinoi sp. nov. (Ecuador, Orellana province, EPNC / USNM); 17 – 18. D. bituberculatum (Signoret, 1855) (French Guiana, Cayenne Arrondissement, INHS); 19 – 20. Holotype of D. cavichiolii sp. nov. (Brazil, Mato Grosso State, DZUP); 21 – 22. Holotype of D. gervasioi sp. nov. (Ecuador, Orellana Province, EPNC / USNM); 23 – 24. Holotype of D. olivia sp. nov. (Ecuador, Orellana Province, EPNC / USNM). Scale bars = 5 mm.

FIGURES 25 – 30. Female habitus of species of the Diestostemma bituberculatum complex in dorsal (25, 27, 29) and lateral (26, 28, 30) views. 25 – 26. Paratype of D. albinoi sp. nov. (Ecuador, Orellana Province, USNM); 27 – 28. D. bituberculatum (Signoret, 1855) (French Guiana, Cayenne Arrondissement, DZRJ); 29 – 30. Paratype of D. cavichiolii sp. nov. (Brazil, Mato Grosso State, DZUP). Scale bars = 5 mm.

FIGURES 37 – 45. Habitus of males (37, 39, 41, 43) and females (38, 40, 42, 44 – 45) of the Diestostemma bituberculatum species complex in ventral view. 37 – 38. Holotype and paratype of D. albinoi sp. nov. (Ecuador, Orellana Province, EPNC, USNM); 39 – 40. D. bituberculatum (Signoret, 1855) (French Guiana, Cayenne Arrondissement, INHS, DZRJ); 41 – 42. Holotype and paratype of D. olivia sp. nov. (Ecuador, Orellana Province, EPNC, USNM); 43 – 44. Holotype and paratype of D. gervasioi sp. nov. (Ecuador, Orellana Province, EPNC, USNM); 45. D. rubriventris (Schmidt, 1928) (Peru, Madre de Dios Department, DZRJ). Scale bars = 5 mm.

FIGURES 46 – 55. Diagrammatic representation of the sclerotized dark vein (SDV) areas of forewings of males (46, 48, 50, 52) and females (47, 49, 51, 53 – 55) of the Diestostemma bituberculatum species complex in dorsal view. 46 – 47. D. albinoi sp. nov.; 48 – 49. D. bituberculatum (Signoret, 1855); 50 – 51. D. gervasioi sp. nov.; 52 – 53. D. olivia sp. nov.; 54 – 55. D. rubriventris (Schmidt, 1928). Abbreviations: AM = anal margin; CM = costal margin; CS = claval suture.

FIGURES 56 – 71. Male terminalia of species of the Diestostemma bituberculatum complex, pygofer in lateral view (56, 59, 63, 66, 69), subgenital plate in ventral view (57, 60, 64, 67, 70), and style and connective in dorsal view (58, 61 – 62, 65, 68, 71). 56 – 58. Paratype of D. albinoi sp. nov. (Ecuador, Orellana Province, DZRJ); 59 – 62. D. bituberculatum (Signoret, 1855) and detail of connective variation (French Guiana, Cayenne Arrondissement, INHS); 63 – 65. Holotype of D. cavichiolii sp. nov. (Brazil, Mato Grosso State, DZUP); 66 – 68. Holotype of D. gervasioi sp. nov. (Ecuador, Orellana Province, EPNC / USNM); 69 – 71. Holotype of D. olivia sp. nov. (Ecuador, Orellana Province, EPNC / USNM). Scale bars: 56, 59, 63, 66, 69 = 1 mm; 57 – 58, 60 – 62, 64 – 65, 67 – 68, 70 – 71 = 0.5 mm.

FIGURES 72 – 80. Aedeagi of species of the Diestostemma bituberculatum complex in lateral view (72, 75, 78), basiventral processes in posteroanterior (73, 76, 79) and posteroventral (74, 77, 80) views. 72 – 74. Paratype of D. albinoi sp. nov. (Ecuador, Orellana Province, DZRJ); 75 – 77. D. bituberculatum (Signoret, 1855) (French Guiana, Cayenne Arrondissement, INHS); 78 – 80. Holotype of D. cavichiolii sp. nov. (Brazil, Mato Grosso State, DZUP). Scale bars = 0.5 mm. Abbreviations: AB = aedeagal basiventral process bifurcation; AP = aedeagal basiventral process; AR = aedeagal basiventral process ramus; AS = aedeagal shaft; ED = ejaculatory duct.

FIGURES 87 – 92. Female sternite VII of species of the Diestostemma bituberculatum complex in ventral view. 87. Paratype of D. albinoi sp. nov. (Ecuador, Orellana Province, USNM); 88. D. bituberculatum (French Guiana, Cayenne Arrondissement, DZRJ); 89. Paratype of D. cavichiolii sp. nov. (Brazil, Mato Grosso State, DZUP); 90. Paratype of D. gervasioi sp. nov. (Ecuador, Orellana Province, USNM); 91. Paratype of D. olivia sp. nov. (Ecuador, Orellana Province, USNM); 92. D. rubriventris (Schmidt, 1928) (Peru, Madre de Dios Department, DZRJ). Scale bars = 1 mm.