Shining Macromia Dragonfly

Dragonflies (Odonata) start their life as aquatic larvae or nymphs, passing through a series of developmental stages or 'stadia', undergoing several moults as they grow. Before the final moult (5), metamorphosis occurs in which the larvae transform into the adult form (6). Shining macromia dragonflies emerge in May to June, following a larval period of two to three years (2) (3) (5). After emergence, adults undergo a pre-reproductive phase known as the maturation period, and this is when individuals normally develop their full adult colour (6). The maturation period for this species is thought to last one to two weeks, and the entire adult flight period probably only lasts until the end of July to mid-August (2) (3). After maturation, males establish a 50 to 150 m territory along a stretch of river, which they regularly patrol to guard from other males. Females have been observed laying eggs in the water as soon as they arrive at the river. However, since mating at these sites seems to be rare, it is thought that copulation may be performed mainly at feeding sites elsewhere (5). The larvae of this species probably feed on small aquatic animals, and the adults on flying insects, which they capture and devour in flight (3).

Fortunately, many of the sites this dragonfly occupies are far from human settlements and relatively free from the threat of pollution (2). Furthermore, this species seems capable of a degree of behavioural adaptation to cope with its changing environment, demonstrated by its ability to inhabit vegetation-free hydroelectric reservoirs (5). The population at the Lindoso reservoir also occurs within a protected area, the Xures Natural Park. This species is protected by law in Spain, and a permit is needed to collect it. Furthermore, with recent data revealing that it is less rare than previously believed, this dragonfly appears to be in no immediate danger of extinction, and its long-term conservation prospects look hopeful (2).

This emblematic species is the only European representative of the Macromia dragonflies, a genus that is widespread and abundant throughout tropical regions of the world (2). The sides of the head of the shining macromia dragonfly are entirely yellow, while the top features two large symmetrical yellow spots, separated by a black furrow. The greenish-black thorax is patterned with yellow spots, and the long, slender black abdomen is also adorned with a series of yellow markings (3). The large eyes are a striking emerald green, a characteristic feature of the Corduliidae family, commonly known as the emerald dragonflies or the green-eyed skimmers.

Adults prefer to breed in slow-flowing rivers, with deep, warm water, sandy or muddy bottoms, and abundant vegetation. Small populations have also been found at shallow, rapid waters, and are even known to breed successfully in hydroelectric reservoirs, despite the absence of aquatic and riverine vegetation. Almost all populations are at low altitudes of up to 250 to 300 m above sea level, but one population has been recorded at 620 m, and a single larva at 640 m. Recently, a population was also found in Northern Spain at 1000 m, likely due to the river it occupies being warmed up by waters from a lake during summer (4). Larvae live amongst tree roots, and may live under leaf debris, but their presence at vegetation-free reservoirs suggests they may also live shallowly buried in the muddy substrate of the water bottom (2).

Confined to southernmost France and scattered localities in the Iberian Peninsula (Spain and Portugal) (2) (3).

Classified as Vulnerable (VU) on the IUCN Red List 2006 (1), and included in Annex II of the Bern Convention as “strictly protected”, and in Annex II of the Habitats Directive as a species whose conservation requires the designation of special areas of conservation (2).

The main threats facing the shining macromia dragonfly are habitat destruction and water pollution, as the result of agricultural, industrial, urban and tourist activities (2) (3). Although the species breeds in some man-made reservoirs, hydroelectric dams and other modification of water courses will usually have a negative impact (2). A further concern is the dramatic droughts that repeatedly affect Iberia, and thus the availability of suitable breeding ground for the shining macromia dragonfly (1).