International Journal of Odonatology 4 (2): 135-166, 200 I © 2001 Backhuys Publishers. 135 Revision of the subgenus Marmaraeschna (Odonata: Aeshnidae) Javier Muzon & Natalia von Ellenrieder CONICET- lnstituto de Limnologfa Dr. Raul A. Ringuelet, C.C. 712, 1900 La Plata, Argentina. <[email protected]>; <[email protected]> Received 26 June 2000; revised 15 January 2001; accepted 02 April 2001. Key words: Odonata, dragonfly, Aeshna, Marmaraeschna, Neotropics. Abstract This revision of the subgenus Marmaraeschna includes the description of three new species: Aeshna (M.) fissifrons, A. (M.) obscura and A. (M.) brevicercia, as well as redescriptions of the previously known species, including the first description of the male of A. (M.) pallipes, a key for males and females and an updated distribution for each species. Useful characters are the presence or absence of black stripes over frontoclypeal and fronto-ocular grooves, T -spot shape, abdominal colour pattern, ventral terga contour and cerci shape. Introduction The neotropical subgenus Marmaraeschna Calvert was erected in 1952 to receive Aeshna brevifrons Hagen, A. intricata Martin and A. vigintipunctata Ris. The characters proposed for this subgenus were: pterothoracic marbled colour pattern, abdominal segment (S) 1 with a ventral tubercle, supratriangular crossveins present, vein IRl beginning proximal to the level of the pterostigma or under the proximal end or proximal half of the pterostigma, anal triangle 3-celled, male with a middorsal longitudinal carina on S 10 and male cerci with the apex not bifid nor with an anteapical ventral point. Some years later a fourth species, A. pallipes Fraser, was added (Calvert 1956). Up to now, the taxonomic situation of this subgenus has been very confusing, due to the few specimens collected, the poor preservation of the type material, the vague original descriptions and several misidentifications in the only previous revision of this group (Calvert 1956). Marmaraeschna species are distributed mainly in the Andes, approximately from 400 to 4,000 m. They are found in lotic environments of the Andean mountain range, from Venezuela in the north to 33°S in Argentina and Chile, and in the central Argentine hills, with Sierra de La Ventana (38°S), Buenos Aires province, their southernmost known locality. The record of A. brevifrons from Mexico (Hagen 1861) and those of A. intricata from Mexico and Brazil (Martin 1908) are here considered erroneously assigned to those countries (see distribution of each species). 136 The goal of this work is to clarify the confusing taxonomic situation by means of introducing new specific characters, redescribing available type material, re-examining most of the collected specimens and elaborating a specific key. Material and methods Examined specimens are deposited at the following collections: ANSP -The Academy of Natural Science, Philadelphia, PA., USA DRP -Dr. Dennis R. Paulson private collection, Washington, USA FML - Fundaci6n e Instituto Miguel Lillo, Tucuman, Argentina FSCA - Florida State Collection of Arthropods, Gainesville, USA IADIZA- Instituto de Investigaciones de Zonas Aridas, Mendoza, Argentina IEUM - Instituto de Entomologia, Universidad Metropolitana de Ciencias de la Educaci6n, Santiago, Chile. IZA - Instituto de Zoologfa Agricola, Maracay, Venezuela MACN - Museo Argentino de Ciencias Naturales "Bernandino Rivadavia", Buenos Aires, Argentina MCZ - Museum of Comparative Zoology, Harvard, USA MHNS - Museo Nacional de Historia Natural de Santiago, Chile MLP - Departamento Cientffico Entomologfa, Museo de La Plata, La Plata, Argentina MNB - Humboldt-Universitlit, Museum fiir Naturkunde, Institut fiir Systematische Zoologie, Berlin, Germany PUC - Departamento de Biologfa, Pontificia Universidad Cat6lica, Quito, Ecuador RWG -Dr. Rosser W. Garrison private collection, California, USA UMMZ -University of Michigan, Museum of Zoology, M.I., USA USNM -U.S. National Museum, Washington D.C., USA WB - Dr. Wilfried Braun private collection, Berlin, Germany Type material studied Holotype female of Aeshna (Marmaraeschna) pallipes and, by present designation, lectotype male and paralectotype female of A. (M.) brevifrons. Synonymic lists For each species a synonymic list is given, including all corroborated previous records (by means of specimen re-examinations or drawing comparisons). For the records that have not been corroborated, a second synonymic list is given. Regarding the specimens studied by Calvert (1956), only those examined in the present work and those that have been redetermined based on the drawings and/or descriptions of Calvert are included. In the lists of material the following symbols regarding the specimens studied and/or mentioned by previous workers are used: * = specimen recorded by Calvert (1956); + = specimen illustrated by Calvert (1956); ** = specimen recorded by Fraser (1947); 137 I= specimen recorded by De Marmels (1988); II= specimen recorded and illustrated by De Marmels (1988); III= specimen recorded by Schmidt (1952). Descriptions For each new species complete descriptions of holotype and allotype are given. Paratypes variations are given in square brackets. Previously known species are briefly redescribed, except for the male of Aeshna pallipes Fraser, described herein for the first time. Characters examined Head: T-spot shape, development of black stripes on fronto-ocular and fronto-clypeal grooves and frontal ridge shape. Thorax: colour pattern and wing venation. Abdomen: colour pattern, ventral terga contour, cerci overall shape and subbasal tooth and dorsal ridge development. Male genitalia were examined for each species, but we did not found any useful and consistent character. Holotype and allotype measurements are included in their descriptions; range, mean and standard deviation for each species as well as wing venation characters are included in Tables 1 and 2. Drawings were made using a net reticule. Distribution area is based only on the examined material and corroborated records. Aeshna (Marmaraeschna) (Figs 1-2) Of the six diagnostic characters proposed by Calvert (1952, 1956) for the subgenus Marmaraeschna, the only exclusive one is the pterothoracic marbled colour pattern, which is composed of black spots and stripes over pale areas. The black stripes are located along the ventral margin of mesepimeron, metepistemum and metepimeron, and along the ventro-dorsal grooves. This pattern can be organised and described as follows (Fig. 1): 1: At dorsal 0. 75 of mesanepisternum, next to mesanepisternum-mesepimeron groove. 2: At dorsal 0.60 of mesepimeron, approximately halfway between mesanepisternum- mesepimeron and mesepimeron-metepisternum grooves. 3: At dorsal 0.75 of mesepimeron, at the level of mesepimeron-metepisternum groove. 4: At 0.50 over mesepimeron-metepistemum groove. 5: At dorsal 0.60 of metepistemum, approximately halfway between mesepimeron- metepisternum and metepisternum-metepimeron grooves. 6: At dorsal 0.75 of metepistemum, next to metepisternum-metepimeron groove. 7: At dorsal 0.60 of metepimeron, next to metepistemum-metepimeron groove. 8: At ventral 0.40 of metepimeron, halfway between metepistemum-metepimeron groove and posterior margin of metepimeron. Spots 2 and 3 are usually confluent, as well as 5 and 6, and 4 is usually confluent with the black stripe located over mesepimeron-metepisternum groove. Table I. Marmaraesch11a species measurements (mm): range, mean and standard deviation; number of specimens (11). w -00 Head maximum width Head maximum width/ Cerci length Cerci oEpiproct o Epiproct frons width maximum width length length/ cerci length 0 'i' 0 'i' 0 'i' 0 'i' A. (M.) brevicercia 8.9- 10 9.5- 10.2 1.9 - 2.8 1.9- 2.3 5.4- 5.9 2.7-3 0.7- 1 0.55- 0.7 2- 2.7 0.38-0.46 9.53 ± 0.24 9.88±0.31 2.22 ±0.22 2.12±0.12 5.57±0.18 2.8 ± 0.13 0.87 ±0.09 0.62 ±0.06 2.34 ± 0.17 0.42 ± 0.03 11 = 18 11=6 11 = 18 11=6 11 = 17 11=6 11 = 17 11=6 11 = 18 11 = 17 A. (M.) brevijro11s 8.6-9.1 8.7-9.5 1.5 - 1.7 1.5 - 1.9 4.2-4.8 1.9- 2.3 0.6- 1.0 0.5 2- 2.65 0.47-0.6 8.93±0.16 9.11±0.27 1.67±0.15 1.7 ± 0.16 4.47 ± 0.31 2.03 ± 0.15 0.79 ± 0.11 2.39 ± 0.2 0.53 ± 0.05 11=8 11=6 11=8 11=6 11=7 11=6 11=7 11=6 11=8 11=7 A. (M.) jissijro11s 8.4- 9.4 8.2- 9.6 1.7-2.1 1.6 - 1.8 3.5-4.5 1.7- 2.2 0.6-0.7 0.45-0.6 2-2.6 0.52-0.65 8.72 ±0.4 8.97 ± 0.45 1.82 ± 0.16 1.72 ± 0.08 3.95 ± 0.36 1.91 ± 0.17 0.65 ±0.05 0.52 ±0.05 2.27-0.24 0.57 ± 0.06 11=4 11=8 11=4 11=8 11=4 11=8 11=4 11=7 11=4 11=4 A. (M.) intricata 9- 9.45 9.2- 9.5 1.9- 2.4 1.7-2 4.9- 5.5 3.7 0.8- 0.85 0.8 1.9-2.4 0.37-0.49 9.28 ± 0.25 9.38 ± 0.16 2.16±0.25 1.86 ± 0.15 5.16 ± 0.3 0.8 ±0.03 - 2.23 ±0.28 0.43 ± 0.06 11=3 n=3 11=3 n=3 11=3 n=J 11=3 n=2 11=3 11=3 A. (M.) obscura 10- 10.6 10.4- 10.7 2.2- 2.5 2.2- 2.5 5.8 - 6.5 5.6-6 I - 1.25 1.4 2-3 0.34-0.46 10.22 ±0.2 10.5 ± 0.21 2.31 ±0.11 2.35 ± 0.21 6.03 ±0.24 5.8 ± 0.28 1.1 ± 0.1 - 2.46 ± 0.32 0.4 ± 0.04 11=6 n=2 n=6 n=2 11=6 n=2 11=6 n=2 11=6 n=6 A.