Rediscovery ofMesagrion leucorrhinum(Zygoptera: Megapodagrionidae): a “formal” description of female and ultimate stadium of larva with notes on habits

Abstract

Adult female and ultimate stadium larva of Mesagrion leucorrhinum are formally described and illustrated based on material from three locations in Antioquia, Meta and Cundinamarca Departments, Colombia. The species is sexually dimorphic. The ♀ is distinguishable from other related genera by a pair of notches in the prothoracic anterior lobe and shares with Heteropodagrion and Dimeragrion females a yellowish, scarcely sclerotized region dorsally between the posterior margin of S7 and anterior border of S8. The larva is very similar to Heteropodagrion. Differences for separating them are: the pro-, meso-and metathoracic supracoxal processes are less prominent in Mesagrion, and the length of the terminal filament of the middle gill is notably longer in Mesagrion. The specimens were also compared with other related genera. Observations on habits are added. La Hembra y la larva en último estadio de Mesagrion leucorrhinum son formalmente descritas e ilustradas basadas en material de Colombia de tres localidades en los departamentos de Antioquia, Meta y Cundinamarca. Existe marcado dimorfismo sexual en la especie. La ♀ es distinguible de otros géneros relacionados por un par de muescas en el lóbulo anterior del protórax, dorsalmente presenta en el borde posterior del S7 y base del S8 una zona escasamente esclerotizada de color amarillo, similar a la que se observa en hembras de Heteropodagrion y Dimeragrion. La larva es muy similar a la de Heteropodagrion. Diferencias para separarlas son: los procesos supracoxales en pro-, meso-y metatórax son menos prominentes en Mesagrion, y el tamaño del filamento terminal en la branquia media es marcadamente más largo en Mesagrion. Los ejemplares fueron comparados con géneros relacionados. Adicionalmente se presentan datos sobre hábitos.

Redefining the damselfly families: a comprehensive molecular phylogeny of Zygoptera (Odonata)

“…The only other damselflies described as having such gills are the Madagascan Protolestes and South American Dimeragrion . Our analyses implied these are not related to Argiolestidae, which is supported by other details of the larval gills and adult morphology (Tennessen, ; Pérez‐Gutiérrez & Montes‐Fontalvo, ; Kalkman & Theischinger, ). Another apomorphy is a central ridge of tubercles on the male cerci, which is present in all genera and absent only secondarily in a few species.…”

Generic revision of Argiolestidae (Odonata), with four new genera

“…However, in these genera the filaments are articulated at the base, whereas in Dimeragrion the terminal filament is unarticulated. Based on the larval characters both Tennessen (2010) and Pérez-Gutiérrez & Montes-Fontalvo (2011) suggested Dimeragrion to be more closely related to one of the genera in which the gills are saccoid. This also fits better with the presence of setae on the shaft of the genital ligula in Dimeragrion given that these are absent in all other species included in Argiolestidae but present in most other genera of Megapodagrionidae sensu lato.…”