Sunday, October 28, 2012

Mating Damselflies

About a month ago, I walked the 8-mile path around Forsythe National Wildlife Refuge in Oceanville, New Jersey (near Atlantic City). The walk takes several hours for those of us who constantly stop to take photographs and to identify birds and butterflies. There were many many pairs of damselflies mating in the marsh grass that day.

It is not immediately obvious (to us) what is going on during damselfly and dragonfly sex. Here are the basics: An amorous male begins by producing sperm from genitalia at the tip of his abdomen (tail). He transfers the sperm package to receptacles under his belly. Then he goes off to find a female.

When he locates a likely mate, he grabs her by the head with hooks on the end of his abdomen; his claspers fit precisely to females of his species. The claspers-to-head position is called a mating chain. Sometimes they  fly while connected like this.

They eventually perch. The female curls to pick up the male's sperm with the tip of her abdomen, getting into a position called a mating wheel (some call it a heart). Click here to see a halloween pennant dragonfly mating wheel in a previous blog post.

And from the obscure trivia department. The damselfly has a very nice name in Dutch -- it's called a waterjuffer.