The Norfolk Hawker dragonflies are all around us at Carlton at the moment. Big, brown and beautiful with jade green eyes, they often create a sudden rattling sound as their wings beat stems as they take off from amongst reeds. It’s like being in the midst of a bunch of tiny croupiers mixing packs of cards.
Handsome beasts!
A mating pair of Norfolk Hawkers
In this pic the male is above, clasping the neck of the female with his claspers, which fit into special grooves on her neck, specific to species -a key and lock system which may have evolved to prevent successful mating between species.
He has already successfully driven off competing males and attracted her to his territory, and has already transferred sperm from his primary genital opening on the 9th abdominal segment. near the tail end of the abdomen, to his secondary genitalia at the second and third abdominal segments, nearer the thorax.
If the female is ready, she will curl her abdomen under and forward to bring her genitalia into contact with the male’s secondary genitalia, allowing the transfer of sperm and insemination.
After the initial clasping, the pair may fly together till the male finds a perch to cling on to. The shape they make is called the “heart” or “wheel”. After mating, the female needs to lay her eggs, but before this the male may fly with her, still clasped, to prevent other males mating with her. He may also spend some time cleaning out her genitalia with his penis to remove any possible sperm from rivals.
Here the female is depositing her eggs (ovipositing) on a stem of vegetation. This is a very vulnerable time as she is at risk from predators such as fish or fen raft spiders. The method of ovipositing varies between species. Some possess a sharp ovipositor used to slit vegetation so the eggs can be deposited inside, others lay eggs in the water and some drop them in flight.
Although the shot below is rather poorly focussed, I wanted to include it and the series below as it shows a pair of damsel flies after mating. The male is clasping the female and took off and landed in different places several times. Every time they landed she oviposited.
When I get a chance to take better shots I’ll replace these -but I was thrilled to get a chance to witness this -just the day after writing the main part of this post.
