Dragonflies and Damselflies
Species Identification Notes
These identification notes are applicable to mature 'normal' form adults that are found in the county of Lincolnshire. They are intended to highlight characteristics which are, for the most part, readily visible in the field with the aid of a bit of patience and close-focussing binoculars.
A good field guide, the 'Hammond' is particularly recommended, is essential for anybody wishing to take the study of Odonata any further. The order in which the species are presented is not classification order. Scientific names and English names follow those used in the "Atlas of the dragonflies of Britain and Ireland", by Merritt et al (1996).
Anisoptera, the Dragonflies, are large, powerful insects, with their wings held out at right angles to the body at rest. Two families are represented.
Aeshnidae, the Hawkers, are the archetypal dragonflies, big, long-bodied, powerful fliers. They are usually difficult to approach and care should taken with identification, especially if they are in flight. Once settled, a pair of binoculars is a great help in sorting out the species, as well as clues from habitat and flight period.
Libellulidae, the Chasers, initially look very similar to each other, but careful observation, possible in the field with binoculars, allows them to be readily identified. They have a stout appearance, body length appearing much shorter in relation to wingspan than exhibited by the hawkers. Flight is usually low to the water, fast and direct, rarely performing the aerial acrobatics of the hawkers. Careful field observation will reveal a favoured perch, usually a dead stick or sun-trap on the ground, that they will habitually return to at frequent intervals, allowing the observer good views.
The Darters are also members of the Libellulidae and are the smallest of the dragonflies, physically resembling mini hawkers in shape and behaviour, although they are more closely related to the chasers. They perch in a distinctive manner with the wings swept forwards and downwards. Mature males that occur in the county are readily identifiable, but care needs to be exercised with females, immatures and old specimens.
Zygoptera, the Damselflies are typified by their small size compared to dragonflies; very thin bodies, and wings folded across the back at rest, certainly never at right-angles as in the dragonflies. Three families are represented.
- Calopterygidae – Demoiselles
- Lestidae - Emeralds
Green bodies, clear wings and an unusual habit of settling with its wings half open immediately identify this group.
- Coenagrionidae – Typical Damselflies
The Common Blue, Azure and Variable Damselflies comprise the typical and widely noted blue damsels, the males being identifiable at close range with a bit of practise and some degree of patience. The females are more difficult and will only be dealt with superficially here.
Fully accurate identification of the species can only be achieved by examination of features such as anal appendages, as some degree of variation can be exhibited in the markings and colouration of both sexes of the three species. Space dictates that only the typical forms will be discussed here.
