Last update on : 1 JUNE 2013 SUN 3:44PM

Libellago semiopaca  (Selys, 1873)

Found in Asia: Indonesia, Malaysia

Libellago semiopaca FEMALE

A matured female Libellago semiopaca. Notice a layer of white powder (white pruinescence) covering the whole lower part body from thorax to the tip of abdomen.

Libellago semiopaca is a small damselfly. This female size is :
The whole body length = 22 mm
Hind wing length = 19 mm

The following two female photographed on the same day at the same location. One is Pale Green while another is Yellowish Brown. The Yellowish brown is likely immature female.

Libellago semiopaca FEMALELibellago semiopaca FEMALE

Libellago semiopaca MALE

A female Libellago semiopaca’s unique big fat nose.

Libellago damselfly species have unique extended frons making these damselflies look as if having big fat noses. These nose shape separate them from other similar Rhinocypha species in Malaysia.

View from top of a female Libellago semiopaca.

The marking is very similar to a Libellago lineate except that L. lineate is yellowish while L. semiopaca is greenish (bluish for male)

This matured female Libellago semiopaca has developed white pruinescence (like white powder) over the lower thorax and lower abdomen. The white powder make a matured female lost her bright color and look dull in appetence.

Although small, Libellago semiopaca  is perhaps the most conspicuous member of the genus. It is brightly marked on the dorsum of the abdomen with pale green, and the forewings bear broad dark terminal patches which are used to signal aggressively to other males.

There is a good deal of variation in the extent of the green marking and of the dark patch, but present opinion holds that there is just one species.

Males spend many hours in contests facing each other, hovering around almost the same spot. A climactic event in aggressive behavior is the 'stationary-wing display', during which the dominant male flies with his hind wings while holding the dark-tipped forewings outstretched and motionless, facing the opponent. An opponent confronted with this display shows considerable agitation, rocking rapidly from side to side, and often abandons the contest.

Courtship too, is often protracted with the male swinging to and fro as close as 10 cm in front of the female. Curiously, the males lack the white coloration on the legs found on other species. During courtship the legs dangle limply below the body rather than being thrust toward the female in display. Almost all females which land in a male's territory and attempt to oviposit are courted vigorously. Following a successful courtship, mating takes place on the log just above the water.

The pair remain together for about a minute . Females are guarded while they remain in a male's territory but they often oviposit in groups in company with Rhinocypha species. Females in groups almost never respond to courtship; at this stage they are probably not receptive and courting males become disorientated with respect to which female they have selected. Males also rest on logs near the water while waiting for females, and both sexes often fall prey to Dolomedes spiders . Individuals which escape such depredations may live for about 10-14 days after they commence reproduction, spending their entire life stationed around the same log.

Libellago semiopaca is locally common on clear forest streams and near the banks of broad rivers throughout Sundaland.

Males are tenacious in combat; protagonists often hover facing each other for minutes.

Libellago semiopaca contests for territories are time consuming  lasting  as much as  4minutes. The males face each other and hover rather than move vertically during the territorial dispute.  The pair rotates horizontally 90 degrees and offer a series of stationary wing displays until a winner is decided.

Courtship of  Libellago semiopaca  (Selys, 1873) male and female does not involve legs, which are black.

INDEX : Damselfly     March 15, 2016 08:25:49 PM