Diversity for Damselflies

Today, 14th June, started typically dull, cool and windy but the clouds suddenly cleared in time for the damselflies to demonstrate their flying and hunting abilities in the sun along the river.

 They were active in numbers in every sunny and sheltered spot amongst numerous midges skimming the water surface, hunting and catching prey then pausing to pose on a chosen leaf for a while, then off again. Banded Demoiselle,  Beautiful Demoiselle and Large Red damselflies were the most numerous, some preferring calm and still waters whilst others prefer locations where the water is fast flowing.

Here, the rivers provide a suitable diversity of habitat to suit these different species, with plentiful and diverse bankside vegetation.

 A Banded Demoiselle damselfly (Calopteryx splendens) male on a hazel leaf in the afternoon sun this

afternoon. The dark band, like a thumb print on each wing gives it its name - but only the males have this characteristic and they are more often seen chasing and perching in the sun. The females enjoy dense nettlebeds and tall fresh grasses where they merge into the background colours.

The spikes along the legs are used for catching prey such as flies on the wing and hold the prey securely whilst it is eaten. 

This shows the fine structural engineering of the wing, very light but very strong, operated by strong wing shoulder muscles.

The same Banded Demoiselle damselfly and its shadow on its hazel

 leaf, showing its relative size. 

(the leaf has been chewed by another insect, probably caterpillars)

This damselfly is a Large Red damselfly (Pyrrhosoma nymphula) male, perching on a favoured

nettle leaf on the river bank. It's not all that large, but they vary in size according to the timing of their emergence, those emerging early in the year being larger as early hatching larvae usually have the best choice of locations for feeding. This year was not typical, as these Large Reds emerged late, together with other species of damselfly, whereas they are normally the very first to emerge in the late spring.