Austropetaliidae

Muzón, Javier, Pessacq, Pablo & Lozano, Federico, 2014, The Odonata (Insecta) of Patagonia: A synopsis of their current status with illustrated keys for their identification, Zootaxa 3784 (4), pp. 346-388 : 381-385

Austropetaliidae ( Figs. 55 , 56 a)

This small family of four genera and 10 species ( Garrison et al. 2006) is represented also in Australia and Tasmania. In Patagonia it is represented by the genera Hypopetalia (monotypic: H. pestilens ) and Phyllopetalia , with five species: P. apicalis , P. apollo , P. excrescens , P. pudu and P. stictica . All the species are present in southern Chile, but only H. pestilens , P. apollo and P. pudu have also been recorded in southwestern Argentina (von Ellenrieder 2005; Pessacq & Brand 2009).

Phyllopetalia altarensis has been recorded from central Chile (von Ellenrieder 2005), and it is included here since its known distribution area is close to the northern limit of Patagonia.

The genus Phyllopetalia was revised by von Ellenrieder (2005), who synonymized four genera, four species, and one subspecies, provided keys for adults (herein reproduced) and distributional and taxonomic information. The larval knowledge of the family is still poor, with only the larvae of H. pestilens and P. apollo known ( Schmidt 1941; Pessacq & Brand 2009) with certainty. The larva of P. stictica was described by supposition ( Schmidt 1941), and some characters of P. pudu were provided by Pessacq & Brand (2009), also associated by supposition.

Austropetalids mainly inhabit shaded forests with small streams and rivulets. Carle (1996) mentions a semiterrestrial habitat for Phyllopetalia, Baird (2013) observed a larva that he tentatively identified as a Phyllopetalia sp. under a log next to a water-filled micro-depression, and Pessacq & Brand (2009 and pers. obs.) found larvae of Hypopetalia pestilens , Phyllopetalia apollo and Phyllopetalia sp. in small streams (1–2 m wide) within Nothofagus forest and on non-native Douglas-fir ( Pseudotsuga menziesii ) plantations. Larvae were found in crevices of small falls, clinging under logs or between pebbles and debris. The characteristic lateral lobes of the abdominal segments having a serrated aspect possibly mimicks Nothofagus leaves. Exuviae of Phyllopetalia apollo have been found at the top of a pine tree ( Pinus contorta ) cut at a height of about 2 m ( Pessacq & Brand 2009).

Females of Phyllopetalia apollo have been seen flying close to the water's surface and ovipositing in the moist surface of logs protruding from water; adults of Hypopetalia pestilens have been seen flying close to the water's surface, but also at tree-top level, at heights of more than 10 m (Pessacq pers. obs.). On several occasions males and females have been captured with malaise traps placed across small shaded streams ( Muzón & Spinelli 1995).

Neopetaliidae ( Fig. 52 b)

This monotypic family was established by Carle & Louton (1994) for Neopetalia punctata . This remarkable species has a restricted distribution from 33º S in central Chile to 43º S, being recorded in the Nothofagus forest of Argentina approximately between 40º S and 43º S and from sea level to 1,700 m.a.s.l. ( Carle & Louton 1994; Muzón 1997a).

Larvae are shallow burrowers and were found in small muddy streams and seepages ( Carle & Louton 1994); in Argentina this species has been found in small shaded streams with riparian bamboo patches within Nothofagus forests. Adult behavior has been described by Carle & Louton (1994).

Libellulidae ( Figs. 56 b, 57)

This cosmopolitan family is represented in Patagonia by seven species in three genera: Dasythemis mincki , Erythrodiplax atroterminata , E. connata , E. corallina , E. nigricans , E. ochracea , and Sympetrum villosum .

The biogeographical aspects of these species differ considerably. For example, D. mincki is recorded in Patagonia only from the Valcheta stream headings in Somuncura volcanic plateau, where it is locally abundant. The presence of this neotropical species in northern Patagonia, disjunct some 1,000 km southeast of the nearest population (Uspallata river, Mendoza province), could be explained by the thermal nature of the stream headings on this plateau ( Muzón 1997a; Spinelli & Muzón 2000; Muzón et al. 2005). On the other hand, the cosmopolitan genus Sympetrum is represented only by the endemic S. villosum , which is a common inhabitant of ponds of the Nothofagus forest area between 41° S and 46° S (Muzón & von Ellenrieder 1997). Finally, the species of the neotropical genus Erythodiplax present in Patagonia have large distribution areas within Argentina, except for E. connata , a true Patagonian species, which extends slightly north to the southern portion of Mendoza province (del Palacio & Muzón 2012); all the species of Erythrodiplax are represented in Patagonia by their southernmost populations.

Most of the non-strict Patagonian Erythrodiplax are inhabitants of ponds and marshes, being rare in the northern steppe area (north to 42º S), except for E. corallina which is recorded both in the forest area of Chile and in the steppe areas of Argentina. Erythrodiplax connata is a common and locally abundant species north to 44º S.

In the northern steppe, only three libellulids have been recorded in sympatry: Dasythemis mincki , Erythrodiplax atroterminata , and E. connata ( Muzón et al. 2005; Muzón et al. 2010). There are two other libellulids recorded in the steppe, Erythrodiplax corallina and E. nigricans , but only from isolated records; however, it is likely that all five will be found in sympatry.

All the larvae of Patagonian libellulids have been described ( Carvalho et al. 1991; von Ellenrieder & Muzón 2000; von Ellenrieder 2007; Garré et al. 2008; Lozano et al. 2011). Those of Sympetrum and Dasythemis are easily recognized by labial palp features. Larvae of Erythrodiplax are harder to identify at the specific level, except for that of E. connata , the only one without lateral abdominal spines.

Corduliidae ( Fig. 58 )

Dijkstra et al. (2013) proposed a restricted Corduliidae , excluding the genus Gomphomacromia which is left as incertae sedis within Libelluloidea. For practical purposes we include this genus in Corduliidae . Corduliidae is a cosmopolitan family represented by only two genera and three species in Patagonia: Gomphomacromia chilensis , G. paradoxa , and Rialla villosa . The genus Rialla is monotypic and endemic.

The genus Gomphomacromia was revised by von Ellenrieder & Garrison (2005), who synonymized G. mexicana Needham, 1933 , with G. chilensis , and G. etcheverry Fraser, 1957 , with G. paradoxa . Gomphomacromia chilensis is a poorly known species endemic to central Chile, reaching Patagonia at its northern border, approximately 35º S; locality data are few. Gomphomacromia paradoxa occurs all along the Andean range approximately from 32º to 51º S.

The larvae of Gomphomacromia paradoxa and Rialla villosa have been described ( Needham & Bullock 1943; Theischinger & Watson 1984); that of G. chilensis remains unknown.

Gomphomacromia paradoxa inhabits mountain streams, seepages and bogs, and it can be found in large numbers; males defend their territory and tandems land by the side of the streams (von Ellenrieder & Garrison 2005). Larvae of this species seem to be semi-terrestrial (von Ellenrieder & Garrison 2005).

Rialla villosa inhabits lakes and ponds in the Nothofagus forest. Adults fly straight close to the water; copulation takes place during flight; tandems perch on trees ( Jurzitza 1975), adults perch occasionally on grass and bushes, usually in vertical position ( Jurzitza 1989a). Larvae were collected in oligotrophic lakes with the aid of dredges from 20 m depth (Muzón 1995).

Figures

FIGURE 52. Distribution maps. a Neogomphus edenticulatus and N. bidens; b N. molestcus, Progomphus joergenseni, and Neopetalia punctata.

FIGURE 55. Distribution maps. a Hypopetalia pestilens and Phyllopetalia excrescens; b P. stictica and P. pudu.

FIGURE 56. Distribution maps. a Phyllopetalia apollo and P. apicalis; b Erythrodiplax corallina, E. ochracea, and E. nigricans.

FIGURE 58. Distribution maps. a Gomphomacromia paradoxa and G. chilensis; b Rialla villosa.