Oreiallagma acutum ( Ris 1918 ) Ris, 1918

Ellenrieder, Natalia Von & Garrison, Rosser W., 2008, Oreiallagma gen. nov. with a redefinition of Cyanallagma Kennedy 1920 and Mesamphiagrion Kennedy 1920, and the description of M. dunklei sp. nov. and M. ecuatoriale sp. nov. from Ecuador (Odonata: Coenagrionidae), Zootaxa 1805, pp. 1-51 : 44-45

Oreiallagma acutum ( Ris 1918) comb. nov.

Figures 27 ; 51; 85; 90; 104

Acanthagrion acutum Ris 1918: 120 –122, figs. 61–62 [mislabeled as 59] (description of male, illustration of S10 and wings).

Cyanallagma acutum Kennedy 1920: 87 (inclusion in Cyanallagma ).

Davies & Tobin 1984: 66 (synonymic list).

De Marmels 1989: 246–247, figs. 1–7 (notes on male and illustrations of head, posterior lobe of prothorax, S7–10, genital ligula, and S10).

Garrison 1991: 11 (synonymic list).

Bridges 1994: VII.3 (synonymic list).

Steinmann 1997: 247 (synonymic list as Cyanallagma acuta ). De Marmels 1997: 138, fig. 82 (key to northern Cyanallagma species, map, comparison with C. thelkterion ). Tsuda 2000: 31 (synonymic list).

Types: Ris (1918) described this species based on nine males (three from Río Zongo, six from Coroico) but did not designate a holotype. We examined a male syntype labeled "Río Zongo, 800 m. / BOLIVIA. [La Paz Dept.] 1913 (2), A.H. Fassl", which also has a red label "Lecto-[in ink by an unknown hand]/Para-/typoid [printed]" affixed to the envelope. De Marmels (1989) stated that he examined two paralectotypes from Coroico. In order to clarify application of the name, we designate the specimen we examined as lectotype (Senckenberg Register No. 10196) that served as basis for our Figures 27 ; 51; 85; 90. In FNS.

Characterization. Medial lobe of posterior lobe of prothorax slightly constricted at base, subquadrate, with shallow medial concavity on posterior margin ( Fig. 27 ; as in O. oreas and O. quadricolor ). Distal segment of genital ligula ( Fig. 51 ) approximately as wide at apex as at base with a pair of latero-apical lobes recurved and directed basally, no accessory latero-medial lobes (unique), and two ental membranous transverse folds (as in O. quadricolor and O. thelkterion ). Dorsal process of male cercus approximately as long as ventral process ( Figs. 85 ; 90; unique). Dorsum of S1–7 black, of S8–9 blue, sides of S3–7 reddish-orange, of S8 with a black stripe along anterior 2/3, S9 entirely blue and S10 entirely black. Female unknown.

Diagnosis. Species unique by cercus morphology: the long, digit-like dorsal process ( Fig. 85 ) is shared only with O. thelkterion ( Fig. 86 ) but is more robust and as long as or longer than ventral process ( Figs. 85 ; 90); in O. thelkterion , dorsal process is more acuminate and shorter than ventral process ( Fig. 86 ). In O. prothoracicum ( Figs. 87 ; 92) and O. quadricolor ( Figs. 88 a; 93), dorsal process is small and acute, and in O. oreas it is represented by a blunt setose tubercle ( Figs. 89 ; 94).

Biology. Unknown; see remarks under generic account.

Distribution. Bolivia (La Paz Department), from 800 to 1400 m above sea level ( Fig. 104 ).

Figures

FIGURE 104. Distribution of species of Oreiallagma in South America.

FIGURES 25 – 29. Posterior lobe of prothorax. (25) Oreiallagma prothoracicum, male paratype, Ecuador, Intaj, (a) dorsal view, (b) medio-dorsal view; (26), O. oreas, male holotype, Colombia, Monte Socorro, dorsal view; (27) O. acutum, male lectotype, Bolivia, Río Zongo, dorsal view; (28) O. quadricolor, Peru, (a – b) posterior lobe of prothorax, male, holotype, Santa Ana, (a) dorsal view, (b) antero-lateral view, (c) female, Morro Leguía, dorsal view; (29) O. thelkterion, Venezuela, dorsal view, (a) male, Monte Zerpa, (b) female, Guaramacal.

FIGURES 49 – 53. Distal segment of male genital ligula, (a) lateral view, (b) ectal view, (c) ental view. (49) Oreiallagma thelkterion, paratype, Venezuela, Monte Zerpa; (50) O. quadricolor, holotype, Peru, Santa Ana; (51) O. acutum, lectotype, Bolivia, Río Zongo; (52) O. oreas, holotype, Colombia, Monte Socorro; (53) O. prothoracicum, paratype, Ecuador, Intaj. i. p.: inner process; l-ap. l.: latero-apical lobe; l-m. l.: latero-medial lobe; te. f.: terminal fold; tr. f.: transverse fold; scl. l-ap. f.: sclerotized latero-apical fold.

FIGURES 85 – 89. Male caudal appendages, medio-dorsal view, (86 b) medial view of cercus, (88 b) medio-ventral view, (88 c) dorsal view. (85) Oreiallagma acutum, lectotype, Bolivia, Río Zongo; (86) O. thelkterion, paratype, Venezuela, Monte Zerpa; (87) O. prothoracicum, holotype, Ecuador, Intaj; (88) O. quadricolor, holotype, Peru, Santa Ana; (89) O. oreas, holotype, Colombia, Monte Socorro. d. p.: dorsal process; v. ap. p.: ventro-apical process; v-b. p.: ventro-basal process; scal. cu.: scalariform-like cuticle.