Description of the final instar larva of Argia serva Hagen in Selys, 1865 (Odonata Coenagrionidae)

Alejandro Del Palacio,Javier Muzón,Federico Lozano

doi:10.1590/0001-3765201820180093

Alejandro Del Palacio, Javier Muzón + Show 1 more

Open Access

https://doi.org/10.1590/0001-3765201820180093

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Abstract

The American genus Argia, with more than 100 species described, is the most speciose genus of Odonata in the world. In this contribution, the final stadium larva of Argia serva, the southernmost distributed species of Argia, is described and diagnosed based on reared material from Martín García island, Buenos Aires, Argentina. The larva of this species can be easily separated from the other Argentinean Argia by the following combination of characters: sternum of S8 covered with spines (bare in A. translata); antennal segment 3 longer than 1+2 (equal to or shorter than 1+2 in A. joergenseni and A. jujuya); palpal setae absent (present in A. croceipennis). A key to the known larvae of Argia of the Southern Cone is provided.

Highlights

The American genus Argia, with 123 species described (Garrison and von Ellenrieder 2017) and many more species under description, is the most speciose genus of Odonata in the world
Correspondence to: Alejandro del Palacio E-mail: adelpalacio@undav.edu.ar inhabitants of lotic environments, most species of Argia prefer low to mid order streams (Westfall and May 1996; Caesar and Wenzel 2009); labium lacks well developed dorso-apical premental setae; labial palp usually with 1–4 setae, distally ending in two hooks; caudal lamellae generally ending in a filamentous tip (Novelo-Gutiérrez 1992)
Lilacina Selys, A. modesta Selys, A. mollis Hagen in Selys, A. reclusa Selys, A. serva Hagen in Selys, A. sordida Hagen in Selys, A. translata Hagen in Selys, and A. yungensis Garrison & von Ellenrieder (Lencioni 2006; von Ellenrieder and Muzón 2008). From these the larvae of only five have been described: A. croceipennis, A. joergenseni, A. jujuya, A. sordida, and A. translata (Costa et al 2008; Geijskes 1946; Molineri and Rodriguez 2013; Santos 1968; von Ellenrieder 2007). In this contribution the final stadium larvae of Argia serva, the southernmost distributed species of Argia, is described an illustrated based on reared material from Martín García island, Buenos Aires, Argentina; Scanning Electron Microscope (SEM) pictures of diagnostic characters are given

Summary

Introduction

The American genus Argia, with 123 species described (Garrison and von Ellenrieder 2017) and many more species under description, is the most speciose genus of Odonata in the world. The genus includes small (21 mm in A. bicellulata) to large (57 mm in A. funcki) coenagrionids which are generally black and blue or violet (Garrison and von Ellenrieder 2015); tibial spurs are as long as or longer than twice the intervening spaces; wings are hyaline or tinged with amber or entirely brown; genital ligula variable; males with tori (pillowshaped pads on postero-dorsal margin of S10); male cerci generally entire with basal processes; females without vulvar spine.

Results

Conclusion