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Clave para los adultos de las subfamilias, tribus y generos de Dytiscidae de la Argentina (Coleoptera: Adephaga).

Key to the subfamilies, tribes and genera of adult Dytiscidae of Argentina (Coleoptera: Adephaga)

INTRODUCTION

The family Dytiscidae, commonly known as predaceous diving beetles, belongs to the order Coleoptera, suborder Adephaga. With more than 4,000 described species, it is the world's most speciose family of water beetles (Nilsson, 2001). Although it is cosmopolitan, it displays its greatest diversity in the tropics (Jach & Balke, 2008). Dytiscidae comprises 10 subfamilies, 27 tribes and 180 genera. Approximately half of the species are included in the subfamily Hydroporinae (nearly 2,000 species) and the rest are distributed in the remaining nine subfamilies, as follows: Agabinae (370 species), Colymbetinae (130 species), Copelatinae (540 species), Coptotominae (5 species), Dytiscinae (380 species), Hydrodytinae (4 species), Laccophilinae (400 species), Lancetinae (22 species), Matinae (8 species) (Nilsson, 2001). Considering the new records given in the present study, the Argentinean fauna of Dytiscidae includes eight subfamilies (only Coptotominae and Matinae are absent), 16 tribes, 31 genera and 119 species (Tremouilles, 1998; Michat et al., 2008).

Eggs, larvae and adults of almost all dytiscid species are aquatic and live in a wide variety of freshwater habitats. They are usually found in lentic water bodies, such as steppe lakes, ponds, forest puddles, large lakes, springs, phytotelmata, hygropetric sites and alpine lakes up to 4,700 m in altitude (Tremouilles, 1995; Balke et al., 2004). In reference to lotic environments, dytiscids are most commonly observed in rivers and streams with a greatly reduced flow rate (Tremouilles, 1995). In general, most species prefer habitats with abundant aquatic vegetation, so meso- and eutrophic sites will usually feature a rich diving-beetle community (Balke et al., 2004). Pupation occurs in cells constructed by the mature larva on land, relatively close to the water (Larson et al., 2000). In some cases, dytiscids are adapted to extreme environments, such as freshwater bodies situated on caves or underground (Tremouilles, 1995). In spite of being one of the most typical aquatic families, Dytiscidae has three genera inhabiting rainforest leaf litter and soils in mountainous areas of the Indian subcontinent and northeastern Australia (Jach & Balke, 2008; Larson et al., 2000).

Water beetles derive from terrestrial ancestors and have acquired a suite of adaptations that enable an aquatic existence (Larson et al., 2000). The adults have respiratory adaptations that allow them to breathe atmospheric air, such as the presence of hydrofuge hairs covering the last two abdominal tergites (Tremouilles, 1995). Moreover, they have adaptations to the aquatic locomotion, such as an oval and dorsoventrally flattened body shape, and the last pair of legs broadened, flattened and provided with natatory setae that aid in underwater propulsion (Larson et al., 2000; Tremouilles, 1995). Dytiscidae are also known for playing several important roles in aquatic ecosystems, such as preying upon mosquito larvae (Ohba & Takagi, 2010), and being good indicators of biodiversity (Sanchez-Fernandez et al., 2006) and contamination (Fernandez-Diaz et al., 2008).

Several keys for the identification of adults of the South American genera of Dytiscidae were presented in the past (Tremouilles, 1995; Tremouilles et al., 1995; Benetti et al., 2003 and Archangelsky et al., 2009). Even though they represent important contributions for the identification of the Argentinean genera, all of them have problems that may lead to misidentifications when applied to the Argentinean fauna. Some of these problems are: inclusion of genera that are absent in Argentina, exclusion of genera that are present, use of outdated synonyms and genus-group names, use of genital characters, use of sexually dimorphic characters, and lack of illustrations. To provide a solution to these problems, in this contribution we present a key for the identification of the subfamilies, tribes and genera of adult Dytiscidae of Argentina, including all the genera known so far to be present in our country, using updated nomenclature and avoiding the use of genital and sexually dimorphic characters (or if used, accompanied by other characters). Also, a large number of illustrations is included to assist in the identification process. One subfamily and five genera are cited for the first time for Argentina.

MATERIAL AND METHODS

In total, 73 species were examined, representing all the 31 dytiscid genera present in Argentina. Most of the material was obtained from collecting trips to several Argentinean provinces (Buenos Aires, Chubut, Cordoba, Corrientes, Entre Rios, Jujuy, Misiones and Tucuman) and Paraguayan departments (Alto Paraguay, Canindeyu and Presidente Hayes). Specimens of Megadytes magnus Tremouilles & Bachmann, M. robustus (Aube) and Hydaticus tuyuensis Tremouilles were borrowed from the Museo Argentino de Ciencias Naturales Bernardino Rivadavia, and specimens of Neobidessus alvarengai Young and N. pullus (Le Conte) were donated by Dr. G. Challet (Bohart Museum, USA).

Measurements were taken using a micrometer eyepiece mounted on a Leica MZ6 stereoscopic microscope. Total length (TL; = largo total: LT) was measured from the anterior clypeal margin to the elytral apex. Greatest width (GW; = ancho maximo: AM) was measured in the widest part of the specimens. The ratio TL/GW was calculated when shape was important for identification.

Drawings were made using a Leica MZ6 stereoscopic microscope or an Olympus CX31 compound microscope, both equipped with a camera lucida. The structures observed with the compound microscope were previously cleared in lactic acid and mounted on glass slides with polyvinyl-lacto-glycerol. Drawings were scanned and digitally edited using a Genius tablet. Micrographs were obtained using a Philips XL30 TMP New Look scanning electron microscope controlled by the software Analysis.

The following abbreviations were used in the figures: Clm (clypeal margin); Cs (cervical stria); CxI (procoxa); CxII (mesocoxa); CxIII (metacoxa); El (elytron); Elas (accessory stria of elytron); Elbs (basal stria of elytron); Epl (epipleuron); Eplc (epipleural carina); M2 (medial vein 2); Msem (mesoepimeron); Mtcxl (metacoxal line); Mtest (metaepisternum); Mtst (metasternum); Mtstk (metasternal keel); Mttac (metatarsal claw); Obc (oblongum cell); Prnt (pronotum); Prpl (propleuron); Prpr (prosternal process); Prst (prosternum); Prta2-4 (protarsomeres 2-4); Sc (scutellum).

The characters used in the key were identified by direct observation of the specimens. Moreover, an exhaustive literature survey was performed in order to find characters that complement those already selected by direct observation. Characters of external morphology and chaetotaxy were privileged, mainly those showing little or null variation within the taxa and also visible at common magnifications. Variable characters were in general accompanied by other characters to assist in the identification process. Morphometry, distribution, and coloration pattern were employed in some cases.

In order to identify the dorsal, ventral, anterior and posterior surfaces, the proand mesothoracic legs were considered to be stretched out at right angles to the body. In the metathoracic legs, however, the metacoxae are fused to the metathorax, and the remaining segments are rotated (in different degrees) with respect to their original position. The metafemur and metatibia, for example, are rotated about 90[degrees] so that the true anterior surface has become the ventral surface. The metatarsus is further rotated so that its primarily anterior surface is now the dorsal surface. In the present key we follow the criterion of Larson et al. (2000) and use the terms dorsal, ventral, anterior and posterior to refer to the apparent position of the metathoracic leg segments.

RESULTS
Key to subfamilies, tribes and genera of
adult Dytiscidae of Argentina

1. Prosternal process in separate (more
ventral) plane than prosternum (Fig. 6). Proand
mesotarsus with fourth tarsomere shorter
than third tarsomere and concealed between
two lobes of third tarsomere (Figs. 1-2) (except
Anodocheilus and Bidessonotus, Figs. 3-4).
                                                       Hydroporinae 2

1'. Prosternal process in approximately
same plane as prosternum (Fig. 7). Pro- and
mesotarsus with fourth tarsomere almost as
long as third tarsomere and not concealed
between lobes of third tarsomere (Fig. 5)
                                                                   18

2. Scutellum exposed (Fig. 8)
                                                Methlini, Celina Aube

2'. Scutellum not exposed (Fig. 9)                                  3

3. Mesoepimeron separating metaepisternum
from mesocoxal cavity (Fig. 10). Mesocoxae
contiguous (Fig. 10)
                                                          Vatellini 4

3'. Mesoepimeron not separating
metaepisternum from mesocoxal cavity (Fig.
11). Mesocoxae not contiguous (Fig. 11)
                                                                    5

4. Pronotum with a transverse furrow
near posterior margin (Fig. 12). Greatest
width of pronotum located anterior to
medial transversal line (Fig. 12). Distance
separating anterior ends of metacoxal lines
approximately twice as long as distance
separating posterior ends (Fig. 14). TL more
than 5.2 mm                                             Vatellus Aube

4'. Pronotum without transverse furrow (Fig.
13). Greatest width of pronotum located at
or posterior to medial transversal line (Fig.
13). Distance separating anterior ends of
metacoxal lines approximately as long as
distance separating posterior ends (Fig. 15).
TL less than 5.1 mm
                                                   Derovatellus Sharp

5. Metatarsal claws of unequal length (Fig.
16)                                                      Hyphydrini 6

5'. Metatarsal claws of equal length (Fig. 17)
                                                                    7

6. Distal portion of prosternal process
rhomboid-shaped (Fig. 21). Metasternum
longer than wide at medial region (Fig. 21).
First two antennomeres wider than the others
(Fig. 28). Posterolateral angle of pronotum
projected backward (Fig. 23). TL less than
3.1 mm                                         Desmopachria Babington

6'. Distal portion of prosternal process
triangular-shaped (Fig. 22). Metasternum
approximately as long as wide at medial
region (Fig. 22). First two antennomeres
approximately as wide as the others (Fig.
29). Posterolateral angle of pronotum not
projected backward (Fig. 24). TL more than
3.3 mm                                                Pachydrus Sharp

7. Metacoxal process incised medially (Figs.
25-26)                                                  Hydrovatini 8

7'. Metacoxal process not incised (Fig. 27)
                                                                    9

8. Metacoxal process incision longer than
wide (Fig. 25). Apical portion of elytron
acuminate (Fig. 34). Dorsal color reddish-testaceous
or yellowish-testaceous.
Antennomeres 3-5 (Figs. 30-31) and
metatarsomere 4 (Figs. 17-18) not sexually
dimorphic. TL less than 3.0 mm
                                               Hydrovatus Motschulsky

8'. Metacoxal process incision wider than
long (Fig. 26). Apical portion of elytron not
acuminate (Fig. 35). Dorsal color black to
dark-ferrugineous. Antennomeres 3-5 and
metatarsomere 4 sexually dimorphic: males
with antennomeres 3-5 broader than the rest
(Fig. 32) and metatarsomere 4 bilobed (Fig.
19); females with antennomeres 3-5 as broad
as the rest (Fig. 33) and metatarsomere 4 not
bilobed (Fig. 20). TL more than 4.0 mm
                                                          Queda Sharp

9. Base of metafemur in contact with
metacoxal process (Fig. 27). Metatibia not
curved (Fig. 36). TL more than 4.1 mm
                                                         Hydroporini,
                                       Laccornellus Rough ley & Wolfe

9'. Base of metafemur not in contact with
metacoxal process (Figs. 47-49). Metatibia
curved basally (Fig. 37). Total length less
than 4.0 mm                                              Bidessini 10

10. Head without cervical stria                                    11

10'. Head with cervical stria (Fig. 93-94)
                                                                   13

11. Posterior pronotal stria absent or reduced,
represented by a few punctures not exceeding
posterior third of pronotum (Fig. 40). Elytral
color pattern as in Fig. 41
                                                   Hypodessus Guignot

11'. Posterior pronotal stria present,
exceeding posterior third of pronotum (Figs.
38-39). Elytral color pattern different from
Fig. 41                                                            12

12. Posterior pronotal striae connected
by an irregular transverse furrow (Fig. 39).
Metacoxal lines divergent anteriorly (Fig. 46).
Prosternal process with margins convergent
posteriorly and ventral surface excavated
(Fig. 46)                                        Amarodytes Regimbart

12'. Posterior pronotal striae not connected
by a furrow (Fig. 38). Metacoxal lines
parallel (Fig. 47). Prosternal process with
margins parallel or convergent posteriorly,
and ventral surface not excavated (Fig. 47)
                                                 Bidessodes Regimbart

13. Posterior pronotal striae present,
connected by an irregular transverse furrow
(Fig. 50). Elytron with a keel apparently being
the extension of the pronotal stria (Fig. 50)
                                               Anodocheilus Babington

13'. Posterior pronotal striae absent or,
if present, not connected by a transverse
furrow. Elytron without keels                                      14

14. Epipleura with an oblique carina on
humeral angle (Fig. 92). Elytron without basal
striae. Ratio TL/GW less than 1.75                                 15

14'. Epipleura without carinae on humeral
angle. Elytron with a basal stria (Figs. 44-45).
Ratio TL/GW more than 1.85                                         16

15. Anterior clypeal margin medially
broadened, with two tubercles in the
middle (Figs. 94, 96). TL less than 1.6 mm
                                               Brachyvatus Zimmermann

15'. Anterior clypeal margin not broadened
medially but laterally, without tubercles (Figs.
93, 95). TL more than 2.0 mm
                                              Hemibidessus Zimmermann

16. Pro- and mesotarsus with fourth tarsomere
almost as long as third tarsomere and not
concealed between lobes of third tarsomere
(Figs. 3-4). Metacoxal lines parallel or
slightly convergent anteriorly, reaching apex
of prosternal process (Fig. 48). Prosternal
process with ventral surface not excavated
(Fig. 48). Ventral margin of mesotibia curved
in males (Fig. 51), straight in females (Fig. 52)
                                               Bidessonotus Regimbart

16'. Pro- and mesotarsus with fourth tarsomere
shorter than third tarsomere and concealed
between two lobes of third tarsomere (Figs.
1-2). Metacoxal lines divergent anteriorly,
not reaching apex of prosternal process
(Fig. 49). Prosternal process with ventral
surface excavated (Fig. 49). Ventral margin
of mesotibia straight in both sexes (Fig. 52)
                                                                   17

17. Elytron without accessory striae between
elytral commissure and basal stria (Fig. 44).
Metasternum with lateral keels (Fig. 97).
Elytral color pattern usually fasciate (Fig. 43),
vittate (Fig. 42) or reduced. Pronotum with
or without a medial fuscous spot. Clypeal
margin not broadened anteriorly, without
tubercles above antenna. Distribution: all
throughout Argentina
                                                    Liodessus Guignot

17'. Elytron with an accessory stria between
elytral commissure and basal stria (Fig. 45).
Metasternum without keels. Elytral color
pattern vittate (Fig. 42). Pronotum without
spots. Clypeal margin broadened anteriorly,
with a tubercle above antenna. Distribution:
Salta Province                                      Neobidessus Young

18. Anterior margin of eye rounded, without
a notch above base of antenna (Fig. 54)
                                                        Dytiscinae 19

18'. Anterior margin of eye not rounded,
with a notch above base of antenna (Fig. 53)
                                                                   23

19. Scutellum not exposed (Fig. 9). TL less
than 8.1 mm
                                    Aubehydrini, Notaticus Zimmermann

19'. Scutellum exposed (Fig. 8). TL more than
8.3 mm                                                             20

20. Ventral metatibial spur approximately
twice as wide as dorsal metatibial spur (Fig.
63) Anterodorsal margin of metafemur with
a row of natatory setae (Fig. 55). Apices of
adhesive setae on ventral surface of male
protarsomeres 1-3 oval-shaped (Fig. 58). TL
more than 15.9 mm                                       Cybistrini 21

20'. Ventral metatibial spur approximately as
wide as dorsal metatibial spur (Fig. 64-65).
Anterodorsal margin of metafemur without
rows of natatory setae (Figs. 56-57). Apices
of adhesive setae on ventral surface of male
protarsomeres 1-3 round-shaped (Fig. 59).
TL less than 15.7 mm                                               22

21. Row of setae on posteroapical margin
of mesotibia continuous medially (Fig. 66).
Posterior surface of male mesotarsomeres
and female pro- and mesotarsomeres with
two rows of setae near apical margin (Fig.
66). Males with one metatarsal claw (Fig.
61). Females with two unequal metatarsal
claws (Fig. 60). TL: 26.0-28.0 mm
                                                      Cybister Curtis

21'. Row of setae on posteroapical margin of
mesotibia discontinuous medially (Fig. 67).
Posterior surface of male mesotarsomeres
and female pro- and mesotarsomeres with
one row of setae near apical margin (Fig.
67) . Males with two equal metatarsal claws
(Fig. 62). Females with two metatarsal claws,
either equal (Fig. 62) or unequal (Fig. 60). TL:
16.0-47.0 mm                                          Megadytes Sharp

22. Apices of metatibial spurs simple (Fig.
64) . Anterior margin of metasternal wing
straight (Fig. 68) or slightly curved (Fig.
69). Male mesotarsus with adhesive setae
(Fig. 71). Males with stridulatory apparatus
composed of a field of excavations on dorsal
surface of protarsomere 2 (file) (Fig. 98) and
a row of spines on dorsoposterior margin of
protibia (plectrum) (Fig. 99)
                                          Hydaticini, Hydaticus Leach

22'. Apices of metatibial spurs bifid (Fig. 65).
Anterior margin of metasternal wing strongly
curved (Fig. 70). Male mesotarsus without
adhesive setae (Fig. 72). Males without
stridulatory apparatus on prothoracic leg (Fig.
100)                                    Aciliini, Thermonectus Dejean

23. Scutellum not exposed (Fig. 9).
Metatarsus with one claw (Figs. 73-74).
Mesoepimeron separating metaepisternum
from mesocoxal cavity (Fig. 10). Vein M2 of
wing not connected to oblongum (Fig. 75)
                                       Laccophilinae, Laccophilini 24

23'. Scutellum exposed (Fig. 8). Metatarsus
with two claws (Figs. 79-80). Mesoepimeron
not separating metaepisternum from
mesocoxal cavity (Fig. 11). Vein M2 of wing
connected to oblongum (Fig. 76)                                    25

24. Apices of metatibial spurs simple (Fig.
73). TL less than 2.6 mm
                                                    Unpublished genus

24'. Apices of metatibial spurs bifid (Fig. 74).
TL more than 2.8 mm
                                                    Laccophilus Leach

25. Apex of elytron truncate (Fig. 8)
                                Lancetinae, Lancetini, Lancetes Sharp

25'. Apex of elytron not truncate (Fig. 9)
                                                                   26

26. Metacoxal lines strongly approximated in
middle region (Fig. 77). Anterodorsal margin
of metatarsomeres 1-4 not lobed (Fig. 80)
                                                                   27

26'. Metacoxal lines not strongly
approximated in middle region (Fig. 78).
Anterodorsal margin of metatarsomeres 1-4
lobed (Fig. 79)                                                    29

27. Elytron with long longitudinal striae
(Figs. 81-84). Metacoxa with oblique
striae (Fig. 77). TL more than 4.0 mm
                          Copelatinae, Copelatini, Copelatus Erichson

27'. Elytron without striae. Metacoxa without
striae. TL less than 3.7 mm                                        28

28. Dorsal surface not iridescent. Basal
portion of pronotum and elytra of same
color as other areas of dorsal surface. Middle
portion of prosternal process narrowing
up to half the maximum width of posterior
portion (Fig. 85). TL more than 3.3 mm
                   Copelatinae, Copelatini, Agaporomorphus Zimmermann

28'. Dorsal surface iridescent. Basal portion
of pronotum and elytra lighter in color than
other areas of dorsal surface. Middle portion
of prosternal process not narrowing up to
half the maximum width of posterior portion
(Fig. 86). TL less than 3.2 mm
                         Hydrodytinae, Hydrodytini, Hydrodytes Miller

29. Posteroapical angle of metafemur with
a row of setae (Fig. 87). Metatarsal claws
equal in length (Fig. 91). TL less than 9.0 mm
                                 Agabinae, Agabini, Leuronectes Sharp

29'. Posteroapical angle of metafemur
without a row of setae. Metatarsal
claws equal (Fig. 91) or unequal (Fig.
90) in length. TL more than 10.0 mm
                                         Colymbetinae, Colymbetini 30

30. Body outline discontinuous in dorsal
view, with a visible angle between pronotum
and elytron (Fig. 89). Metatarsal claws
equal in length (Fig. 91). TL: 13.0-15.4 mm.
Distribution: Jujuy and Tucuman Provinces
                                                     Bunites Spangler

30'. Body outline continuous in dorsal view,
without a visible angle between pronotum
and elytron (Fig. 88). Metatarsal claws
unequal in length (Fig. 90). TL: 10.4-17.0
mm. Distribution: all throughout Argentina
                                                       Rhantus Dejean


[FIGURES 1-15 OMITTED]

[FIGURES 16-35 OMITTED]

[FIGURES 36-52 OMITTED]

[FIGURES 53-67 OMITTED]

[FIGURES 68-80 OMITTED]
Clave para los adultos de las
subfamilias, tribus y generos de
Dytiscidae de la Argentina

1. Proceso prosternal en un plano distinto
(mas ventral) que la region media del
prosterno (Fig. 6). Pro y mesotarso con el
cuarto tarsomero mas corto que el tercero
y oculto entre los lobulos de este (Figs. 1-2)
(excepto Anodocheilus y Bidessonotus, Figs.
3-4)                                                   Hydroporinae 2

1'. Proceso prosternal aproximadamente
en el mismo plano que la region media
del prosterno (Fig. 7). Pro y mesotarso con
el cuarto tarsomero casi tan largo como el
tercero y no oculto entre lobulos de este (Fig.
5)                                                                 18

2. Escutelo expuesto (Fig. 8)
                                                Methlini, Celina Aube

2'. Escutelo no expuesto (Fig. 9)
                                                                    3

3. Mesoepimero que separa el
metaepisterno de la cavidad mesocoxal
(Fig. 10). Mesocoxas contiguas (Fig. 10)
                                                          Vatellini 4

3'. Mesoepimero que no separa el
metaepisterno de la cavidad mesocoxal (Fig.
11). Mesocoxas no contiguas (Fig. 11)                               5

4. Pronoto con un surco transversal cercano
al margen posterior (Fig. 12). Ancho
maximo del pronoto ubicado anteriormente
a la linea media transversal (Fig. 12).
Distancia entre los extremos anteriores de
las lineas metacoxales aproximadamente
el doble de la distancia entre los extremos
posteriores (Fig. 14). LT mayor que 5,2 mm
                                                        Vatellus Aube

4'. Pronoto sin surco transversal (Fig.
13). Ancho maximo del pronoto ubicado
en o posteriormente a la linea media
transversal (Fig. 13). Distancia entre
los extremos anteriores de las lineas
metacoxales aproximadamente igual
que la distancia entre los extremos
posteriores (Fig. 15). LT menor que 5,1 mm
                                                   Derovatellus Sharp

5. Unas metatarsales desiguales en longitud
(Fig. 16)                                                Hyphydrini 6

5'. Unas metatarsales iguales en longitud
(Fig. 17)                                                           7

6. Porcion distal del proceso prosternal
romboidal (Fig. 21). Metasterno mas largo
que ancho en su region media (Fig. 21).
Antenomeros 1-2 mas anchos que los
restantes (Fig. 28). Angulo posterolateral del
pronoto prolongado posteriormente (Fig. 23).
LT menor que 3,1 mm
                                               Desmopachria Babington

6'. Porcion distal del proceso prosternal
triangular (Fig. 22). Metasterno tan largo
como ancho en su region media (Fig. 22).
Antenomeros 1-2 aproximadamente del
mismo ancho que los restantes (Fig. 29).
Angulo posterolateral del pronoto no
prolongado posteriormente (Fig. 24). LT
mayor que 3,3 mm                                      Pachydrus Sharp

7. Proceso metacoxal con una incision
en la region media (Figs. 25-26)
                                                        Hydrovatini 8

7'. Proceso metacoxal sin incision en la
region media (Fig. 27)                                              9

8. Incision metacoxal mas larga que
ancha (Fig. 25). Porcion apical del elitro
acuminada (Fig. 34). Coloracion dorsal
testacea-rojiza o testacea-amarillenta. Sin
dimorfismo sexual en los antenomeros
3-5 (Figs. 30-31), ni en el metatarsomero
4 (Figs. 17-18). LT menor que 3,0 mm
                                               Hydrovatus Motschulsky

8'. Incision metacoxal mas ancha que
larga (Fig. 26). Porcion apical del elitro no
acuminada (Fig. 35). Coloracion dorsal
negra a ferruginea oscura. Machos con los
antenomeros 3-5 mas anchos que el resto
(Fig. 32) y con el metatarsomero 4 bilobulado
(Fig. 19). Hembras con los antenomeros 3-5
del mismo ancho que el resto (Fig. 33) y
con el metatarsomero 4 no bilobulado (Fig.
20). LT mayor que 4,0 mm
                                                          Queda Sharp

9. Base del metafemur en contacto con el
proceso metacoxal (Fig. 27). Metatibia no
arqueada en la base (Fig. 36). LT mayor que 4,1
mm
                           Hydroporini, Laccornellus Roughley y Wolfe

9'. Base del metafemur sin contacto con el
proceso metacoxal (Figs. 47-49). Metatibia
arqueada en la base (Fig. 37). LT menor que
4,0 mm                                                   Bidessini 10

10. Cabeza sin estria cervical                                     11

10'. Cabeza con estria cervical (Figs. 93-94)                      13

11. Estria pronotal posterior ausente
o reducida, representada por algunos
puntos impresos que no sobrepasan un
tercio de la longitud del pronoto (Fig. 40).
Patron de color elitral como en la Fig. 41
                                                   Hypodessus Guignot

11.' Estria pronotal posterior bien desarrollada,
sobrepasa un tercio de la longitud del pronoto
(Figs. 38-39). Patron de color elitral distinto
de la Fig. 41                                                      12

12. Estrias pronotales posteriores conectadas
por un surco transversal irregular (Fig.
39). Lineas metacoxales divergentes
anteriormente (Fig. 46). Proceso prosternal
de lados convergentes posteriormente, con
la superficie ventral excavada (Fig. 46)
                                                 Amarodytes Regimbart

12'. Estrias pronotales posteriores no
conectadas por un surco transversal (Fig.
38). Lineas metacoxales paralelas (Fig.
47). Proceso prosternal de lados paralelos
o convergentes posteriormente, con la
superficie ventral no excavada (Fig. 47)
                                                 Bidessodes Regimbart

13. Estrias pronotales posteriores presentes,
conectadas por un surco transversal irregular
(Fig. 50). Elitro con una quilla que parece
continuarse con la estria pronotal posterior
(Fig. 50)                                      Anodocheilus Babington

13'. Estrias pronotales posteriores
ausentes o, si presentes, no conectadas
por un surco transversal. Elitro sin quillas
                                                                   14

14. Epipleura con una carena oblicua en
el angulo humeral (Fig. 92). Elitro sin estria
basal. Cociente LT/AM menor que 1,75
                                                                   15

14'. Epipleura sin carenas en el angulo
humeral. Elitro con estria basal (Figs. 44-45).
Cociente LT/AM mayor que 1,85
                                                                   16

15. Clipeo con el margen anterior engrosado
medialmente y dos tuberculos en el centro
(Figs. 94, 96). LT menor que 1 ,6 mm
                                               Brachyvatus Zimmermann

15'. Clipeo con el margen anterior
no engrosado medialmente sino
lateralmente y sin tuberculos (Figs.
93, 95). LT mayor que 2,0 mm
                                              Hemibidessus Zimmermann

16. Pro y mesotarso con el cuarto tarsomero
casi tan largo como el tercero y no oculto
entre los lobulos de este (Figs. 3-4). Lineas
metacoxales paralelas o ligeramente
convergentes anteriormente, continuan
hasta el apice del proceso prosternal (Fig.
48) Proceso prosternal con la superficie
ventral no excavada (Fig. 48). Margen ventral
de la mesotibia curvado en los machos
(Fig. 51), recto en las hembras (Fig. 52)
                                               Bidessonotus Regimbart

16'. Pro y mesotarso con el cuarto tarsomero
mas corto que el tercero y oculto entre los
lobulos de este (Figs. 1-2). Lineas metacoxales
divergentes anteriormente, no continuan
hasta el apice del proceso prosternal (Fig.
49). Proceso prosternal con la superficie
ventral excavada (Fig. 49). Margen ventral
de la mesotibia recto en ambos sexos (Fig.
52)                                                                17

17. Elitro sin estria accesoria entre la comisura
elitral y la estria basal (Fig. 44). Metasterno
con quillas laterales (Fig. 97). Patron de color
elitral usualmente fasciado (Fig. 43), vittado
(Fig. 42) o reducido. Pronoto con o sin una
mancha oscura central. Margen clipeal no
engrosado anteriormente, sin tuberculos por
encima de las antenas. Distribucion: toda la
Argentina                                           Liodessus Guignot

17'. Elitro con estria accesoria entre la
comisura elitral y la estria basal (Fig. 45).
Metasterno sin quillas laterales. Patron
de color elitral vittado (Fig. 42). Pronoto
sin manchas. Margen clipeal engrosado
anteriormente, con un tuberculo por encima
de la antena. Distribucion: provincia de Salta
                                                    Neobidessus Young

18. Margen anterior del ojo redondeado, sin
muesca sobre la base de la antena (Fig. 54)
                                                        Dytiscinae 19

18'. Margen anterior del ojo no redondeado,
con una muesca sobre la base de la antena
(Figs. 53)                                                         23

19. Escutelo no expuesto (Fig. 9). LT
menor que 8,1 mm
                                    Aubehydrini, Notaticus Zimmermann

19'. Escutelo expuesto (Figs. 8). LT mayor
que 8,3 mm                                                         20

20. Espolon metatibial ventral
aproximadamente el doble de ancho que el
espolon metatibial dorsal (Fig. 63). Margen
anterodorsal del metafemur con una hilera de
setas natatorias (Fig. 55). Apices de las setas
adhesivas ventrales de los protarsomeros
1-3 del macho ovalados (Fig. 58). LT mayor
que 15,9 mm                                             Cybistrini 21

20'. Espolon metatibial ventral de ancho
aproximadamente igual que el espolon
metatibial dorsal (Figs. 64-65). Margen
anterodorsal del metafemur sin hilera de setas
natatorias (Figs. 56-57). Apices de las setas
adhesivas ventrales de los protarsomeros 1-3
del macho redondeados (Fig. 59). LT menor
que 15,7 mm                                                        22

21. Margen posteroapical de la mesotibia
con una hilera continua de setas (Fig. 66).
Superficie posterior de los mesotarsomeros
de los machos y de los pro y mesotarsomeros
de las hembras con dos hileras de setas cerca
del margen apical (Fig. 66). Machos con una
una metatarsal (Fig. 61). Hembras con dos
unas metatarsales desiguales (Fig. 60). LT: 26-28
mm                                                    Cybister Curtis

21'. Margen posteroapical de la mesotibia
con una hilera de setas discontinua en la
region central (Fig. 67). Superficie posterior
de los mesotarsomeros de los machos y de
los pro y mesotarsomeros de las hembras
con una hilera de setas cerca del margen
apical (Fig. 67). Machos con dos unas
metatarsales iguales (Fig. 62). Hembras
con dos unas metatarsales iguales (Fig.
62) o desiguales (Figs. 60). LT: 16-47 mm
                                                      Megadytes Sharp

22. Apices de ambos espolones metatibiales
simples (Fig. 64). Margen anterior del ala
metasternal recto (Fig. 68) o levemente
curvado (Fig. 69). Mesotarso de los machos
con ventosas (Fig. 71). Machos con aparato
estridulador conformado por un grupo
de excavaciones en la cara dorsal del
protarsomero 2 (lima) (Fig. 98) y una hilera
de espinas en el margen dorsoposterior
de la protibia (plectrum) (Fig. 99)
                                          Hydaticini, Hydaticus Leach

22'. Apices de ambos espolones metatibiales
bifidos (Fig. 65). Margen anterior del
ala metasternal marcadamente curvado
(Fig. 70). Mesotarso de los machos sin
ventosas (Fig. 72). Machos sin aparato
estridulador en la pata protoracica (Fig. 100)
                                        Aciliini, Thermonectus Dejean

23. Escutelo no expuesto (Fig. 9). Metatarso
con una una (Figs. 73-74). Mesoepimero
que separa el metaepisterno de la cavidad
mesocoxal (Fig. 10). Vena M2 del ala
no conectada al oblongum (Fig. 75)
                                       Laccophilinae, Laccophilini 24

23'. Escutelo expuesto (Fig. 8). Metatarso
con dos unas (Figs. 79-80). Mesoepimero
que no separa el metaepisterno de la
cavidad mesocoxal (Fig. 11). Vena M2
del ala conectada al oblongum (Fig. 76)
                                                                   25

24. Apices de ambos espolones metatibiales
simples (Fig. 73). LT menor que 2,6 mm
                                                       Genero inedito

24'. Apices de ambos espolones metatibiales
bifidos (Fig. 74). LT mayor que 2,8 mm
                                                    Laccophilus Leach

25. Apice elitral truncado (Fig. 8)
Lancetinae, Lancetini, Lancetes Sharp

25'. Apice elitral no truncado (Fig. 9)                            26

26. Lineas metacoxales muy proximas en su
region media (Fig. 77). Margen anterodorsal
de los metatarsomeros 1-4 no lobulado
(Fig. 80)                                                          27

26'. Lineas metacoxales no muy proximas
en su region media (Fig. 78). Margen
anterodorsal de los metatarsomeros 1-4
lobulado (Fig. 79)                                                 29

27. Elitro con estrias longitudinales
largas (Figs. 81-84). Metacoxa con
estrias oblicuas (Fig. 77). LT mayor
que 4,0 mm
                          Copelatinae, Copelatini, Copelatus Erichson

27'. Elitro sin estrias. Metacoxa sin estrias.
LT menor que 3,7 mm                                                28

28. Superficie dorsal no iridiscente. Porcion
basal de pronoto y elitros del mismo color
que el resto de la superficie dorsal. Region
media del proceso prosternal que se angosta
hasta la mitad del ancho maximo de la region
posterior (Fig. 85). LT mayor que 3,3 mm
                   Copelatinae, Copelatini, Agaporomorphus Zimmermann

28'. Superficie dorsal iridiscente. Porcion
basal de pronoto y elitros de color mas claro
que el resto de la superficie dorsal. Region
media del proceso prosternal que no se
angosta hasta la mitad del ancho maximo de
la region posterior (Fig. 86). LT menor que 3,2
mm                       Hydrodytinae, Hydrodytini, Hydrodytes Miller

29. Angulo posteroapical del metafemur con
un grupo de setas (Fig. 87). Unas metatarsales
iguales en longitud (Fig. 91). LT menor que 9,0
mm
                                 Agabinae, Agabini, Leuronectes Sharp

29'. Angulo posteroapical del metafemur
sin setas. Unas metatarsales iguales (Fig.
91) o desiguales (Fig. 90) en longitud. LT
mayor que 10,0 mm
                                         Colymbetinae, Colymbetini 30

30. Contorno del cuerpo discontinuo en vista
dorsal, con un angulo visible entre pronoto
y elitro. (Fig. 89). Unas metatarsales iguales
en longitud (Fig. 91). LT: 13,0-15,4 mm.
Distribucion: provincias de Jujuy y Tucuman
                                                     Bunites Spangler

30'. Contorno del cuerpo continuo en vista
dorsal, sin angulo visible entre pronoto
y elitro (Fig. 88). Unas metatarsales
desiguales en longitud (Fig.90). LT: 10,4-17,0
mm. Distribucion: toda la Argentina
                                                       Rhantus Dejean


[FIGURES 81-91 OMITTED]

[FIGURES 92-100 OMITTED]

DISCUSSION

The key presented here has several advantages with respect to previous keys used for the identification of adult Dytiscidae of Argentina. As mentioned above (see Introduction), existing keys have several problems when applied to the Argentinean fauna. A first advantage derives from the study of specimens of all the dytiscid genera of Argentina, which allowed us to perform an extensive search for characters that complement the (traditional) characters obtained from the literature. The utility of the traditional characters was also tested and only those that proved to be useful were kept. An emphasis was given to include stable and qualitative characters of the external morphology (to avoid the dissection of the specimens), and to chose characters easily seen at common magnifications. The use of sexually dimorphic characters was restricted as much as possible, and in the cases in which these characters were included, they were accompanied by other (not sexually dimorphic) characters. In the case of quantitative characters we avoided the use of vague terminology and privileged the use of precise measurements and ratios. Finally, we included illustrations of a great number of morphological structures, tending to facilitate the interpretation of the text, and added SEM micrographs to illustrate very small structures.

The subfamily Hydrodytinae and five genera are cited for the first time for Argentina: Agaporomorphus (Copelatinae), Bidessodes (Hydroporinae: Bidessini), Hydrodytes (Hydrodytinae), Queda (Hydroporinae: Hydrovatini) and an unpublished genus of the subfamily Laccophilinae. Moreover, new records are presented for the following provinces: Chaco (Rhantus Dejean, Brachyvatus Zimmermann, Unpublished genus); Corrientes (Agaporomorphus Zimmermann, Anodocheilus Babington, Bidessonotus Regimbart, Derovatellus Sharp, Desmopachria Babington, Hemibidessus Zimmermann, Hydrodytes Miller, Pachydrus Sharp, Queda Sharp, Unpublished genus); Entre Rios (Bidessodes Regimbart, Bidessonotus, Unpublished genus); Mendoza (Celina Aube, Rhantus); Misiones (Agaporomorphus, Celina, Hydrodytes); Santa Fe (Lancetes Sharp).

The finding of Hydrodytes opalinus (Zimmermann) in Argentina (recorded in Corrientes and Misiones Provinces) represents a great expansion of the distributional range of the genus Hydrodytes and of the subfamily Hydrodytinae. Previously, the southern limit of Hydrodytes was northern South America (Miller, 2002). On the other hand, the presence of Queda in Argentina was expected since members of this genus were recorded recently in southern Paraguay (Tremouilles et al., 2004). The specimens of Q. youngi Bistrom were collected in Corrientes Province, so it is probable that this genus is also present in Chaco and Formosa Provinces. Agaporomorphus and Bidessodes also had their distributional limits near Argentina, so their presence in our country corroborates previous hypotheses stating that these genera were probably to be found here (Miller, 2001; Young, 1986).

Anodocheilus maculatus Babington was cited from Buenos Aires and Entre Rios Provinces (Tremouilles, 1995, 1998; Michat & Torres, 2006). This paper incorporates Corrientes Province to the distribution area of the species and the genus. The first mention of Bidessonotus for our country corresponds to Torres et al. (2008), who found an unidentified species in Jujuy Province. Here, we report the finding of specimens of Bidessonotus in Corrientes and Entre Rios Provinces. In our country Brachyvatus acuminatus (Steinheil) was known from Buenos Aires and Entre Rios Provinces (Torres et al., 2007). In the present paper the genus and species are mentioned for the first time for Chaco Province. Hemibidessus was recorded for Buenos Aires and Santa Fe Provinces (Tremouilles, 1995, 1998; Miller, 2000). We report two new species for Argentina (H. conicus (Zimmermann) and H. spiroductus Miller) in Corrientes Province. Desmopachria was known from Buenos Aires, Chaco, Chubut, Cordoba, Entre Rios, Formosa, Jujuy, Mendoza, Misiones, Neuquen, Salta, San Luis, Santa Fe and Santiago del Estero Provinces (Michat & Archangelsky, 2007; Tremouilles, 1995; Torres et al., 2008). On the other hand, the distributional range of Pachydrus included Buenos Aires, Chaco, Entre Rios, Misiones and Jujuy Provinces (Tremouilles, 1995; Torres et al., 2008), and that of Derovatellus included Tucuman, Santa Fe, Entre Rios and Buenos Aires Provinces (Miller, 2005; Torres et al., 2007; Tremouilles, 1995). This paper reports the presence of Desmopachria, Pachydrus and Derovatellus in Corrientes Province. Celina distributes in Formosa, Chaco, Tucuman, Corrientes, Santa Fe, Entre Rios and Buenos Aires Provinces (Torres et al., 2007; Tremouilles, 1995). This paper presents the first record of this genus for Misiones Province. Finally, Rhantus was cited for all Argentinean provinces except Chaco, Formosa, Mendoza and Santiago del Estero (Archangelsky, 2004; Balke, 1992; Tremouilles, 1984, 1995) and Lancetes was cited for all Argentinean provinces except Chaco, Entre Rios, Formosa, Santa Fe and Santiago del Estero (Bachmann & Tremouilles, 1981; Nilsson, 2001; Torres et al., 2008). In this paper Chaco and Mendoza Provinces are added to the distribution of Rhantus and Santa Fe Province to the distribution of Lancetes.

Recibido: 8-VIII-2011; aceptado: 14-X-2011

ACKNOWLEDGEMENTS

We thank two anonymous referees for their helpful comments on the manuscript. This project was funded by an undergraduate scholarship from the University of Buenos Aires, and by the following institutions: National Scientific and Technical Research Council (CONICET PIP 112-20080102759), National Agency for Scientific and Technological Promotion (ANPCyT PICT-2007-01438 and PICT-2010-0526), and University of Buenos Aires (UBACyT-20020090300135).

LITERATURE CITED

1. ARCHANGELSKY, M. 2004. Nuevas citas de Coleoptera acuaticos y Megaloptera para la provincia de Chubut (Argentina). Rev. Soc. Entomol. Argent. 63(3-4): 66-68.

2. ARCHANGELSKY, M., V. MANZO, M. C. MICHAT & P. L. M. TORRES. 2009. Coleoptera. In: Dominguez, E. & H. R. Fernandez (eds.), Macroinvertebrados bentonicos sudamericanos: sistematica y biologia, Fundacion Miguel Lillo, Tucuman, pp. 411-468.

3. BACHMANN, A. O. & E. R. TREMOUILLES. 1981. El genero Lancetes en la Argentina continental (Coleoptera, Dytiscidae). Physis 39(97): 103-118.

4. BALKE, M. 1992. Taxonomische Untersuchungen an neotropischen Wasserkafern der Gattung Rhantus Dejean (Insecta, Coleoptera: Dytiscidae). Reinchenbachia 29(6): 27-39.

5. BALKE, M., M. A. JACH & L. HENDRICH. 2004. Insecta: Coleoptera. In: Yule, C. M. & H. S. Yong (eds.), Freshwater invertebrates of the Malaysian Region, Academy of Sciences Malaysia, Kuala Lumpur, pp. 555-609.

6. BENETTI, C. J., J. A. REGIL CUETO & G. L. FIORENTIN. 2003. Generos de Hydradephaga (Coleoptera: Dytiscidae, Gyrinidae, Haliplidae, Noteridae) citados para o Brasil, com chaves para identificacao. Biota Neotropica 3(1): 1-20.

7. FERNANDEZ-DIAZ, M, C. J. BENETTI & J. GARRIDO. 2008. Influence of iron and nitrate concentration in water on aquatic Coleoptera community structure: Application to the Avia River (Ourense, NW Spain). Limnetica 27(2): 285-298.

8. JACH, M. A. & M. BALKE. 2008. Global diversity of water beetles (Coleoptera) in freshwater. Hydrobiologia 595: 419-442.

9. LARSON, D. J., Y. ALARIE & R. E. ROUGHLEY. 2000. Predaceous Diving Beetles (Coleoptera: Dytiscidae) of the Nearctic Region, with emphasis on the fauna of Canada and Alaska. NRC Research Press, Ottawa.

10. MICHAT, M. C. & ARCHANGELSKY, M. 2007. Descriptions of larvae of Desmopachria Babington (Coleoptera: Dytiscidae: Hydroporinae): the D. vicina Sharp species group. Coleopt. Bull. 61(2): 264-276.

11. MICHAT, M. C., M. ARCHANGELSKY & A. O. BACHMANN. 2008. Generic keys for the identification of larval Dytiscidae from Argentina (Coleoptera: Adephaga). Rev. Soc. Entomol. Argent. 67: 17-36.

12. MICHAT, M. C. & P. L. M. TORRES. 2006. The unknown larva of Anodocheilus Babington (Coleoptera: Dytiscidae: Hydroporinae: Bidessini): description of A. maculatus Babington and chaetotaxic considerations. Trans. Am. Entomol. Soc. 132(3-4): 431-444.

13. MILLER, K. B. 2000. Revision of the Neotropical genus Hemibidessus Zimmermann (Coleoptera: Dytiscidae: Hydroporinae: Bidessini). Aquat. Insects 23(4): 253-275.

14. MILLER, K. B. 2001. Revision of the genus Agaporomorphus Zimmermann (Coleoptera: Dytiscidae). Ann. Entomol. Soc. Am. 94(4): 520-529.

15. MILLER, K. B. 2002. Revision of the subfamily Hydrodytinae Miller (Coleoptera: Dytiscidae) with description of a new genus. InsectSyst. Evol. 33: 1-8.

16. MILLER, K. B. 2005. Revision of the New World and south-east Asian Vatellini (Coleoptera: Dytiscidae: Hydroporinae) and phylogenetic analysis of the tribe. Zool. J. Linn. Soc. 144: 415-510.

17. NILSSON, A. N. 2001. World Catalogue of Insects, volume 3: Dytiscidae (Coleoptera). Apollo Books, Stenstrup.

18. OHBA, S. & M. TAKAGI. 2010. Predatory ability of adult diving beetles on the Japanese encephalitis vector Culex tritaeniorhynchus. J. Am. Mosquito Control Assoc. 26(1): 32-36.

19. SANCHEZ-FERNANDEZ, D, P. ABELLAN, A. MELLADO, J. VELASCO & A. MILLAN. 2006. Are water beetles good indicators of biodiversity in Mediterranean aquatic ecosystems? The case of the Segura river basin (SE Spain). Biodiversity Conserv. 15: 4507-4520.

20. TORRES, P. L. M., S. A. MAZZUCCONI & M. C. MICHAT. 2007. Los coleopteros y heteropteros acuaticos del Parque Nacional El Palmar (Provincia de Entre Rios, Argentina): lista faunistica, diversidad y distribucion. Rev. Soc. Entomol. Argent. 66(3-4): 127-154.

21. TORRES, P. L. M, S. A. MAZZUCCONI, M. C. MICHAT & A. O. BACHMANN. 2008. Los coleopteros y heteropteros acuaticos del Parque Nacional Calilegua (Provincia de Jujuy, Argentina). Rev. Soc. Entomol. Argent. 67: 127-144.

22. TREMOUILLES, E. R. 1984. El genero Rhantus Dejean en la Argentina (Coleoptera, Dytiscidae). Physis 42(102): 9-24.

23. TREMOUILLES, E. R. 1995. Insecta, Coleoptera, Dytiscidae. Fasciculo 1. Dytiscidae: Methlinae-Hydroporinae. Fauna de Agua Dulce de la Republica Argentina 37: 1-82.

24. TREMOUILLES, E.R. 1998. Dytiscidae. In: Morrone, J. J. & S. Coscaron (eds.), Biodiversidad de artropodos argentinos. Una perspectiva biotaxonomica, Ediciones Sur, La Plata, pp. 210-217.

25. TREMOUILLES, E. R., A. OLIVA & A. O. BACHMANN. 1995. Insecta Coleoptera. In Lopretto, E. C. & G. Tell (eds.), Ecosistemas de aguas continentales, Metodologias para su estudio, tomo III, Ediciones Sur, La Plata, pp. 1133-1197.

26. TREMOUILLES, E. R., P. L. M. TORRES & M. C. MICHAT. 2004. New distributional records and comments for the species of the genus Queda (Coleoptera: Dytiscidae). Rev. Soc. Entomol. Argent. 63(1-2): 38-40.

27. YOUNG, F. N. 1986. Review of the water beetles of the genus Bidessodes Regimbart (Coleoptera, Dytiscidae). Entomol. Basil. 11: 203-220.

Appendix 1. Glossary of the terms used in the key

Acuminate: with an acute extreme.

Accessory stria of elytron: short longitudinal groove situated near the basal margin of the elytron, between the elytral commissure and the basal stria.

Antennomere: antennal article.

Basal stria of elytron: short longitudinal groove situated near the anterior margin of the elytron.

Cervical stria: transverse groove crossing the dorsal surface of the head posterior to the eyes.

Clypeus: anterior portion of the head, to which the labrum is attached anteriorly.

Coxal cavity: more or less rounded area surrounded by the sternal and pleural sclerites, in which the coxa articulates.

Elytral apex: distal (posterior) portion of the elytron.

Elytral commisure: straight line along which the elytra meet medially.

Elytral stria: longitudinal groove of the elytron.

Epipleuron: ventral portion of the elytron, situated external to the lateral margins of mesothorax, metathorax and abdomen.

Fasciate: coloration pattern composed of bands whose main axes are perpendicular to the longitudinal axis of the body.

Ferrugineous: reddish-brown color.

Humeral angle: anterolateral angle of the elytron, situated posterior to the pronotum.

Iridescent: reflecting the colors of the rainbow.

Mesoepimeron: posterior region of the mesothoracic pleuron, situated anteriorly to the metaepisternum.

Metacoxa: first segment of the metathoracic leg, fused to the metasternum.

Metacoxal line: longitudinal groove dividing the

metacoxa in two; homologous to the basicostal sulcus of other insects.

Metacoxal process: portion of the metacoxa situated posteriorly between the dividing line of the coxae and the coxa-trochanter articulation.

Metaepisternum: anterior region of the metathoracic pleuron, triangular-shaped, situated posteriorly to the mesoepimeron and between the metasternal wing and the epipleuron.

Metasternal wing: leaf-like portion of the metasternum expanding between the metaepisternum and the metacoxa.

Metasternum: ventral sclerite of metathorax, surrounded by the posterior margin of the mesocoxae and the anterior margin of the metacoxae.

Metatibial spur: spine-shaped and mobile process situated distally on the metatibia.

Oblongum cell: a closed cell in the metathoracic wing.

Posterior pronotal stria: short longitudinal groove situated near the posterior margin of the pronotum.

Pronotum: dorsal portion of the prothorax.

Prosternal process: portion of the prosternum extending posteriorly between the procoxae.

Prosternum: ventral portion of the prothorax, situated posterior to the head.

Scutellum: triangular area of the mesonotum, situated posterior to the pronotum and between the bases of the elytra; it may be covered by the posterior margin of the pronotum resulting in a not exposed scutellum.

Sexual dimorphism: presence of morphological characters particular to one sex, that are absent in the other; it does not correspond to the sexual organs.

Stridulatory apparatus: sound-producing organ consisting of an active structure (plectrum) and a passive structure (file).

Tarsomere: tarsal article.

Testaceous: brownish-yellow color.

Truncate: apparently incomplete, with the aspect of having been cut or interrupted abruptly.

Vittate: coloration pattern composed of bands whose main axes are parallel to the longitudinal axis of the body.

LIBONATTI, Maria L., Mariano C. MICHAT and Patricia L. M. TORRES

CONICET--Laboratorio de Entomologia, Dpto. de Biodiversidad y Biologia Experimental, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina; e-mail: libonatti.marialaura@gmail.com
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Date:Jul 1, 2011
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