Wednesday, March 23, 2022

[Entomology • 2022] The Damselfly Genus Megaloprepus (Odonata: Pseudostigmatidae): Revalidation and Delimitation of Species-level Taxa including the Description of Megaloprepus diaboli, A New Species from Central America

Megaloprepus caerulatus (Drury, 1782)
in copulation wheel on Barro Colorado Island (Panama) 
highlighting the sexual dimorphism.

in Feindt & Hadrys, 2022. 

As the longest-winged odonate species of the extant world, Megaloprepus caerulatus (Drury, 1782) has received attention by many entomologists. While the behavior and ecology of this species has been subject of intense studies, biogeography and species status throughout its distributional range in old-growth Neotropical forests are less well known. For tropical forests, this information is a sine qua non when estimating the impact of degradation and climate change. Recent population genetic analyses, quantitative morphometric, and traditional taxonomic studies rediscovered a complex composed of cryptic species within the genus Megaloprepus Rambur, 1842—up until now still regarded as a monotypic genus. Here we introduce one new species Megaloprepus diaboli sp. nov. from the southern Pacific coast of Costa Rica and from the central Caribbean coast of Honduras and Guatemala. The holotype is from the Corcovado National Park, Costa Rica, and was deposited at the National Museum of Costa Rica. Aside from M. caerulatus, two formerly described and later refused species within the genus were reevaluated and consequently raised to species status: Megaloprepus latipennis Selys, 1860 is found in the northeastern regions of Mesoamerica and Megaloprepus brevistigma Selys, 1860 in South America east of the Andes. Morphological descriptions of selected specimens (holotype of M. diaboli, lectotype of M. latipennis, and the mature males of M. brevistigma and M. caerulatus) are provided. Diagnostic features of the four species are illustrated, discussed, and summarized in a key to adult males.
Keywords: Odonata, Megaloprepus, cryptic species, new species, new species states, Neotropics 

Left hindwings of the four Megaloprepus species.
The metallic blue wing band proximal of the pseudostigma was integrated to visualize its variation, whereas the additional matte white band of M. caerulatus could not be pictured (but see Fig. 6). The scale bar indicates 1 cm.

Megaloprepus caerulatus in copulation wheel on Barro Colorado Island (Panama) highlighting the sexual dimorphism.

Megaloprepus caerulatus (Drury, 1782)
Range. The nominal species M. caerulatus has a high number of records. Its distribution covers in Central America the Southern Caribbean coast of Nicaragua (Indio Maíz Biological Reserve), the Caribbean slope of Costa Rica (National Park Tortuguero, Biological Research Station La Selva, Hitoy-Cerere Biological Reserve) and Barro Colorado Island. In South America it occurs in the Northern part of Colombia at the Caribbean side, and on the Pacific side of the Andes ranging from Colombia to Peru (West of the Andes). 

Megaloprepus diaboli Feindt & Hadrys sp. nov.

Etymology. This species was named after the common name for damselflies in Latin America: ‘Caballitos del Diablo’. It was given in the hope to raise attention for Odonates and their highly endangered habitats in the Neotropics to support their conservation.

Range. Observed distributional range is old-growth rainforests of the Peninsula de Osa, the southern West Coast of Costa Rica, at the Atlantic Coast of Honduras, Atlántida Province (e.g. Pico Bonito National Park) and the Atlantic Coast of Guatemala between Morales and Puerto Barrios.

Megaloprepus latipennis (Selys, 1860)

Range. Megaloprepus latipennis occurs in the southern, tropical parts of Mexico, in particular in the Los Tuxtlas Biosphere Reserve (Veracruz), Chiapas and Oaxaca, the northern parts of Guatemala such as the National Park Laguna Lachua (Coban, Alta Verapaz, close to Chiapas in Mexico) and the western Guatemala such as the Río Bravo region. 

Megaloprepus brevistigma Selys, 1860

Range. All M. brevistigma specimens were located at the east side of the Andes leading towards the Amazon Basin. In Colombia museum samples from Bogota were assigned to M. brevistigma and M. caerulatus, which allows the assumption of possible overlapping regions.

 The present study of the Neotropical damselfly genus Megaloprepus supports the historical hypothesis that Megaloprepus is not a monotypic genus. Although most research on Megaloprepus has been carried out in Costa Rica and Panama, some distinct behavioral characters may be applicable to all four species within the entire range of the genus. In addition to the same ecological niche, one important feature shared is the sensitivity to heat and consequently low dispersal abilities over open areas. This behavioral pattern in combination with increasing forest fragmentation of old-growth forests in the Neotropics results in restricted distributional ranges and geographic isolation. Consequently, the conservation status of the four species should be re-evaluated, also by considering regional/local endemism. 

Wiebke Feindt and Heike Hadrys. 2022. The Damselfly Genus Megaloprepus (Odonata: Pseudostigmatidae): Revalidation and Delimitation of Species-level Taxa including the Description of One New Species. Zootaxa. 5115(1); 487-510. DOI: 10.11646/zootaxa.5115.4.2

Conservation genomics: Speciation of the Neotropical damselfly species Megaloprepus caerulatus – as a model for insect speciation in tropical rainforests