Orthetrum chrysis (Selys, 1891)

Found in Asia: China, Guandong, Hong Kong, Hainan, India, Sri Lanka, Myanmar, Malaysia, Philippines, Peninsular Malaysia, Singapore, Thailand

Identification Guide to Male and Female 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

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)

MALE ♂	FEMALE ♀
Orthetrum chrysis 2016-03-19 SAT 16:22 SG IMAM	Orthetrum chrysis 2016-03-19 SAT 15:07 SG IMAM
Ventral View of a male Orthetrum chrysis	Ventral View of a female Orthetrum chrysis
Face of a male Orthetrum chrysis	Face of a female Orthetrum chrysis
Wing venation of a male Orthetrum chrysis	Wing venation of a female Orthetrum chrysis
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).	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.

Dragonflies and damselflies have large compound eyes that can see in all directions. When the compound eye is magnified several hundred times, each individual facet (ommatidium) is shown to be hexagonal in shape.

Female dragonflies have either one of the two method of depositing eggs from the abdomen:
1- using Ovipositor Structure
2- using Vulvar Lamina

Male do not have an ovipositor. Instead male dragonfly and damselfly have appendages.

GO FURTHER

FLORA

Fig trees of Sabah

Borneo has 150 species of wild fig trees. Most of them are found in forests of Sabah.

FISHERIES

Tiger Prawn Farms in Tawau

Prawn farming is a main commercial activities in Tawau. Spawners from Tawau are graded the best in Malaysia. For decades, Tawau has been exporting high-grade tiger prawns to several countries such as Korea, Japan, Taiwan, China, Vietnam, Singapore, Egypt and Australia.

O. pruinosum	O. chrysis	O. 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

O. pruinosum	O. chrysis	O. testaceum	Rhodothemis rufa