Template:POTD/2020-07-04

Picture of the day

Enallagma cyathigerum, the common blue damselfly, is a species of damselfly in the family Coenagrionidae. The species is widely distributed across the Palearctic realm and can reach a length of 32 to 35 mm (1.3 to 1.4 in).

This composite photograph, taken in Oxfordshire, England, shows a pair of E. cyathigerum damselflies preparing to mate. Having transferred a bundle of sperm known as a spermatophore to secondary genitalia on the third segment of his abdomen, the blue-coloured male grasps the dull-coloured female by the head with the claspers at the tip of his abdomen. The female then curls her abdomen downwards and forwards under his body to pick up the sperm from the male's secondary genitalia. The distinctive posture that the pair adopt when transferring sperm is often called the "heart" or "wheel".Photograph credit: Charles J. Sharp