Orthetrum chrysis (Selys, 1891)

Found in Asia: China, Guandong, Hong Kong, Hainan, India, Sri Lanka, Myanmar, Malaysia, Philippines, Peninsular Malaysia, Singapore, Thailand
Sub-Order: ANISOPTERA Super-Family: LIBELLULOIDEA Family: LIBELLULIDAE

In the same Genus Orthetrum | Orthetrum chrysis  | Orthetrum glaucum Orthetrum sabina   |  Orthetrum testaceum   |


Orthetrum pruinosum Orthetrum chrysis Orthetrum testaceum Rhodothemis rufa

♀41mm
2016-09-16 MINI HYDRO

♀42mm
2016-03-19 SG IMAM

♀46mm
2007-10-21 DRAGONFLY POND

♀45mm
2017-06-09 WHITE BRIDGE POND



The 4 easily confused Male Red Dragonflies of Borneo
 
Orthetrum pruinosum Orthetrum chrysis Orthetrum testaceum Rhodothemis rufa
Orthetrum pruinosum Orthetrum chrysis Orthetrum testaceum Rhodothemis rufa

O. pruinosum

O. chrysis

O. testaceum


R. rufa

 

The Genus Orthetrum is distinguished by :
1) Complete antenodal cross vein
2) Discoidal field in the forewing has  3 cell rows through out.

A Rhodothemis rufa is distinguished by :
1) Incomplete antenodal cross vein
2) Discoidal field in the forewing has both 2 cell rows and 3 cell rows.

 




Eyes meet partially along a seam (arrowed)


Eyes barely touch at a centre point (arrowed)

 


Sungai Imam, Sabah

Video in March 2016


MALE
FEMALE
Orthetrum chrysis  MALE
Orthetrum chrysis

2016-03-19 SAT 16:22 SG IMAM

Orthetrum chrysis FEMALE
Orthetrum chrysis

2016-03-19 SAT 15:07 SG IMAM

Ventral View of  a male Orthetrum chrysis
Ventral View of  a male Orthetrum chrysis
Ventral View of a female Orthetrum chrysis
Ventral View of a female Orthetrum chrysis
Face of a male Orthetrum chrysis
Face of a male Orthetrum chrysis
Face of a female Orthetrum chrysis
Face of a female Orthetrum chrysis
Wing venation of a male Orthetrum chrysis
Wing venation of a male Orthetrum chrysis
Wing venation of a female Orthetrum chrysis
Wing venation of a female Orthetrum chrysis
Segment 8, 9 and 10 of a male dragonfly

Upper appendages (One pair)
Lower appendage (Single)
Testes (sperm production organ located on the underside of abdominal segment 9)

Segment 8, 9 and 10 of a male dragonfly

Cerci (singular cercus) are paired appendages on the rear-most segments of many Arthropoda, including insects and Symphyla.

Anisoptera males only have upper appendages, plus one single small knob that is also called lower appendage.
Female odonates only have very small appendages, which are functionless. These are called cerci. See image at right

But Zygoptera males have two pairs of anal appendages: the upper appendages (appendices superiors) and the lower appendages (appendices inferiors).
 

Segment 8, 9 and 10 of a female dragonfly

Appendages (Cerci)
Eggs

For the female dragonflies , genitalia are located underneath the abdomen between segment 8 and 9.

Zygoptera and some Anisoptera (Aeshnidae and Cordulegaster) have an ovipositor, surrounded by valvae. An ovipositor is used to stick eggs in plants, wood or mud. These species are called endofytic.

This Orthetrum chrysis is not a Zygoptera, thus does not have an ovipositor.

Species that don’t have an ovipositor (exofytic) simply drop their eggs into the water.


Identification Guide to ♂♀Orthetrum chrysis

Identification Guide to
♂♀Orthetrum chrysis
common in marshes and clear streams of Borneo
 

MALE

♂48mm

Body length = 48mm
Wing span = 77mm
Hind wing = 37mm

 

FEMALE

42mm♀
Body length = 42mm
Wing span = 72mm
Hind wing = 35mm

 

yellowish egg-mass

 

S1

Ref: Page 98 of DRAGONFLIES OF PENINSULAR MALAYSIA AND SINGAPORE by A.G. Orr


A female Orthetrum chrysis of Sabah, Malaysia
 

A female Orthetrum chrysis

Females of genus Orthetrum are greenish brown but this female Orthetrum chrysis is exceptionally red on the abdomen.

It was found just resting on a grass several inches above a weedy mountain drain.

Because this female is extraordinarily red then the normal greenish brown, I could not ascertain that it is an Orthetrum without this wing venation as identification.

This female Orthetrum chrysis measures:
Abdomen width = 4mm
Hing wing length = 32mm
Hind wing span = 69mm
Total body length = 40mm

Female Orthetrum chrysis lacking an ovipositor for laying eggs but instead have a subgenital plate (vulvar lamina) at the rear end of segment 8. The subgenital plate (vulvar lamina) is very short and not obvious to be notice.


Abdomen The abdomen, elongated in all odonates, comprises ten segments, the first and last of which are reduced and often hard to see.

The colour pattern on these segments is often useful in making field identifications, especially with many of the damselflies. (In some cases, especially the clubtail dragonflies , the terminal segments will be dilated into a club likes structure.)

Females typically have slightly broader abdomens than males, and in damselflies, darners, and petaltails an ovipositor (a bladelike egg-laying structure) is evident ventrally on the female’s segment 9.  

A pair of cerci (sing. cercus), extending terminally, is usually visible, though in most groups these are reduced in the female. Males have secondary, or accessory, genitalia, located ventrally on segments 2 and 3. In damselflies, the cerci are enlarged and form a dorsal pair of claspers. Below these is a pair of paraprocts. Together with the cerci, these structures form the caudal appendages, and are used for grasping the female during mating. In dragonflies, the paraproctsare reduced, and a single epiproct is located below the enlarged cerci.

Coloration

The beautiful and varied coloration of odonates is a significant factor in their appeal. In odonates, most of the colours seen result from pigment rather than from structural artifacts of the body. But the bright-blue colour so characteristic of many damselflies is a result not of pigment, but rather of the scattering of light by tiny refractive granules located in epidermal cells; and the metallic coloration seen in many emerald dragonflies is also a result of the insects’ surface structure. In many odonates a pruinescence, or waxy blue-white covering, will develop with age, and as noted above, the newly emerged, or teneral, adult will not have the vibrant colours of its mature counterpart. In many cases, coloration is an important and useful tool for making field identification, but it is important to recognize some of the difficulties of using colour. Odonates of many species are sexually dimorphic in this respect; the males and females differ in coloration. Moreover, many species of damselflies and darners are known to change colours with temperature; individuals will often become darker in colour when exposed to cooler temperatures. This is important to remember when observing odonates on a cool early morning. Several species of pond damsels, such as Springwater Dancer, also become darker while in copulation.


 

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