30/09/2011

Pseudagrion rubriceps (Selys, 1876)


An oviposition spot of Pseudagrion rubriceps (Hanoi), and also a perfect habitat for other common Coenagrionids and Libellulids. 

In Vietnam, Pseudagrion rubriceps is widely distributed throughout the plains and submontane areas. Breeds in and frequents the grassy banks of small streams, ponds. The male is common, but the female is not often seen except when in copula. Though they are common, they are also very shy and it takes a lot of patience to get close to them.
 
A male.

The male is easily distinguished by the brilliant reddish-orange face, from which it derives its name, and which is very conspicuous, even when the insect is on the wing.
The thorax is olivaceous green on dorsum, with a golden tinge as far back as the first lateral suture, the sides azure blue.

S2 show a "wine goblet" (or "cat head"...) shaped mark which reminds me of the one of Coenagrion scitulum (european species). S3-7 black, bronzed green on dorsum, S8 with a broad black cone on dorsum, the apex of cone extending nearly to base of segment the base resting on the apical border of segment; S9-10 azure blue unmarked. 

Male photographed in December, at Hanoi.


 S2 with a goblet- shaped marking on dorsum, the cup with a shallow concavity and its stem very short and confluent with an apical black annule.


Anal appendages (different views above) black, the inferiors paler ; superiors as long as segment 10, broad and deeply hollowed out on the inner side as seen from the dorsum, and with a thick, short, spine-like process on the inner side nearer base than apex; inferiors one-fourth shorter than superiors.

An immature male.

I frequently encountered the female in shaded areas not far from the water's edge. 

A female.
 
Female differs in colour and markings from the male. Head, dorsum and sides of synthorax plain orange-yellow, posterior lobe of prothorax with two short forwardly directed spines at base, S9 with a basal bifid dorsal marking.




Two females. It seems that the markings on dorsum synthorax are quite variable.


Female ovipositing onto the submerged stems of water jacinth (Eichhornia crassipes) with the male in a "sentinel contact" guarding position. This pair remained in tandem for five minutes.

"The end of the road" for this male caught by a wolf spider, a speedy hunter.

P. rubriceps is a widely distributed species. Knows to occur in China (Guangdong, Guangxi, Hong Kong), Taiwan, Bangladesh, Cambodia, India,  Laos, Indonesia, Vietnam, India, Malaysia, Myanmar, Nepal, Pakistan, Philippines, Thailand.

It is certainly the commonest Pseudagrion in Vietnam, where it is widely distributed throughout the plains and submontane areas. It and can be found even inside Hanoi City limits, along very low quality water bodies.

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