Agriocnemis pygmaea (Rambur, 1842) 橙尾細蟌

------------- the world smallest damselfly ------------

http://sjl.csie.chu.edu.tw/phpBB2/viewtopic.php?t=598

Genus : Agriocnemis

The male damselfly's head and thorax is pale green in color with black pattern. Abdomen is pale red with black with the red tail light.

They are not easy to find for they are very small in size. They usually hide low and near the water edge, among thick grasses. They fly slow and float like a moth from one grass to another less than a foot away. 

These two families of Agriocnemis pygmaea and Agriocnemis femina oryzae always live in the same territories.  Because they mingle so close to each other very often the young male of both are mistaken as the other.

A female Agriocnemis pygmaea (Rambur, 1842) 橙尾細蟌 eating a tinny green fly.

Damselflies are beneficial predators because they consume large quantities of insects such as flies, mosquitoes and moths and some eat beetles and caterpillars.

A female Ariocnemis pygmaea (Rambur, 1842) mating at 5:18PM – an unusual time when other dragonflies and damselflies are stopping activities.

A female with this common color is otherwise difficult to identify without this male Ariocnemis pygmaea mate together.

Look how the male clasped her at the shoulder not the neck.
 

Another female Ariocnemis pygmaea (Rambur, 1842) at the same drain of previous picture


Female Ariocnemis pygmaea is a confusing species because of color changes with maturity. It could be easily mistaken as Ariocnemis femina if not the male as a pair for identity.

Or do the two species intermarriage ?

The male curves his abdomen to clasp her prothorax with his anal appendages to form the tandem pair. The male does this clasp less than a second.

The tandem position remained for about 10 minutes during which they flew together from one grass to another to stay away from my camera.

This  heart shape wheel is known as Wheel Position. (In  dragonfly  the tandem  is holding the back of  head.)

 

All  males have their genital opening for sperm at the ninth abdominal segment. Beside the first genitalia male Damselflies  have a secondary genitalia on the second abdominal.

Before copulation,  sperm is moved from the first genitalia (Section 9) into the secondary genitalia (section 2). This is done by The bending the  abdomen forward for the first genitalia to touches the secondary genitalia. This take few seconds. 

When the sperm in the male secondary genitalia is ready, the pair forming a tandem by male holding by female's neck (prothorax).  The female bend up her abdomen to the  of the male's  genitalia and form the wheel position. The female's  abdomen  contact with male's  secondary genitalia  to receive sperm.

The male curves his abdomen to clasp her prothorax.

Noteice that for damselflies the clasping is on the prothorex. But for dragonflies the clasping is on the back of the head