Sunday, February 15, 2009

Damselfly (10) - Argiocnemis Rubescens

Family : Coenagrionidae
Common Name : Variable Sprite
Status : Uncommon
Location : Venus Drive

This is another confusing species because of its age related colour variation.  According to Mr Tang, the  immature of both sexes, the segments 1-5 of the abdomen are orange to cherry red abdomen but this darkens with maturity and the coloration is predominately black and light blue.  This species has unique upper part of eye black with lower part green.  I am still not very sure how to differentiate the male from the female.

(Immature female - Venus Drive, 10 Jan 2009)

Immature female - The abdomen darkened from segments 5-7, segments 2-4 remain red. Colours of abdomen lighter than those of the young male, segments 8-9 do not become light blue.  Synthorax changes from light yellow to yellow and it does not change to light blue as in the young male.

(Mature female - Venus Drive, 13 Jul 2009)

Mature female - Abdominal segments 1-7 are black on dorsum, blue ventrally; segments 8-9 black with tiny patch of blue on the side of segment 8.  Synthorax blue and black with yellow; two narrow blue banks on the dorsum.

(Immature male - Venus Drive, 29 Dec 2008)

Immature male - Abdomen dark from segments 5-7, segments 2-4 remain red, while 8-9 change from light red to light blue. Synthorax is black and blue colour.

(Mature - Venus Drive, 18 Jul 2009)

Mature male - Abdominal segments 1-3 black ondorsum with blue ventrally; segments 4-7 black; segments 8-9 blue.  Synthorax blue and black.


(Immature female? - Venus Drive, June 2009)

My guess of the  above damselfly should be an immature female.  Please drop me a comment if you think otherwise.

(Immature male, close-up side view - Venus Drive, 29 Dec 2008)

(Mature female, close-up side view - Venus Drive, 28 Dec 2008)

Reference : A photographic guide to the Dragonflies of Singapore.

No comments: