Sunday, March 29, 2015

28. Trithemis pallidinervis (Kirby, 1889)

Trithemis pallidinervis (Kirby, 1889)


Number: 28
Family: Libellulidae
Genus: Trithemis  
Species: Trithemis pallidinervis (Kirby, 1889)
Common name: Long Legged Marsh glider
Habitat: Lakes, ponds and riverside
Distribution: Dhaka, Sylhet, Chittagong 
Abundance: Common 
Flight season: March - August

                                             

Male

As the common name suggests, long -legged marsh glider, has long legs, black in color. The head is pinkish.   



The thorax is chocolate color, wings are transparent, pterostigma black, amber wing in the base of wings. 


Abdominal segments are black with white dorsal bands, S 8-10 are completely black, base of the anal appendages are white while tips are black. 


Female

The females are very similar to male. Head is more greenish than male, also the thorax is more yellowish.

Anal appendages are good way to you distinguish female from male. Anal appendages are white.   
  

Saturday, March 28, 2015

27. Diplacodes trivialis (Rambur, 1842)

Diplacodes trivialis (Rambur, 1842)


Number: 27
Family: Libellulidae
Genus: Diplacodes  
Species: Diplacodes trivialis (Rambur, 1842)
Common name: Ground skimmer
Habitat: Lakes and ponds
Distribution: Dhaka, Sylhet, Chittagong 
Abundance: Common 
Flight season: March - November

Diplacodes trivialis is one of the most common dragonflies of Bangladesh. Unlike many other species they spend most of their time outside of the water bodies. They like to rest and fly near to the ground.


                                                                  Male

The males are bluish black. The thorax is blue as well as the abdominal segments 1-8. Segments 9-10 are black, wings transparent, legs black and anal appendages are white 




Female

The females has greenish thorax and abdomnal segments 1-3. Abdominal segments 4-8 has white lateral band, segments 9-10 are black, wings transparent, legs black anal appendages are black. 
  


26. Neurothemis tullia (Drury, 1773)

Neurothemis tullia (Drury, 1773)


Number: 26
Family: Libellulidae
Genus: Neurothemis   
Species: Neurothemis tullia (Drury, 1773)
Common name: Pied paddy skimmer
Habitat: Lakes and ponds
Distribution: Dhaka, Sylhet, Chittagong 
Abundance: Common 
Flight season: March - November


                                                             Male

The males are black and white in color. Head, prothorax, thorax and abdominal segments are black. Wings are black from base till node, white band present in the nodus region, from there till the tip of the wing is transparent, pterostigma black.   



female

The females are also black and white in color. A white band travels from the prothorax, to thorax and reaches till segment 9. Segement 10 is black, anal appendages are white. The tips of the wing is black, also black stripe is present in the nodal region.  



Monday, March 23, 2015

25. Onychrgia atrocyana (Selys, 1865)

Onychrgia atrocyana (Selys, 1865)


Number: 25
Family: Platycnemididae
Genus: Onychrgia  
Species: Onychrgia atrocyana (Selys, 1865)
Common name: Black Marsh dart
Habitat: Lakes, ponds, forest patches
Distribution: Dhaka, Sylhet
Abundance: Common 
Flight season: March- November


                                                                 Male

Most of the damselflies of Bangladesh are very colorful, particularly the males. However, unlike many other damselflies Onychrgia atrocyana are black in color. But this unique color has makes it distinct from the other species.  


The juvenile are are like females and can be distinguished from the mature male by the presence of yellow antehumeral stripe.




Saturday, March 21, 2015

24. Ceriagrion cerinorubellum (Brauer, 1865)

Ceriagrion cerinorubellum (Brauer, 1865)


Number: 24
Family: Coenagrionidae 
Genus: Ceriagrion   
Species: Ceriagrion cerinorubellum (Brauer, 1865)
Common name: Orange-tailed Marsh dart
Habitat: Lakes, ponds, rivers
Distribution: All over the country
Abundance: Common 
Flight season: March- November

Ceriagrion cerinorubellum (Brauer, 1865) is one of the most beautiful damselflies of Bangladesh. The colorful species is found all over the country and often found in the pond sides.   

Male

The males are more colorful than female. Thorax is blue, abdominal segments 1-2.5 and 7.5-10 are orange.

The males are yellow, eyes are laterally green. Abdominal segments 3-6 are laterally black. 



The prothorax and thorax is dorsally greenish. 


The eyes are green, frons are gereenish yellow. 


The  hock like anal appendages are black and white in color. 


Female

 The females are similar to male, however the orange color in the abdomen is lighter than male. 

Abdominal segments 9-10 are orange, 3-8 are laterally bluish.  



Thursday, March 19, 2015

23. Anax indicus (Lieftinck, 1942)

Anax indicus (Lieftinck, 1942)


Number: 23
Family: Aeshnidae
Genus: Anax    
Species: Anax indicus (Lieftinck, 1942)
Common name: N/A
Habitat: Lakes, ponds, rivers, forest patches
Distribution: Sylhet
Abundance: Unommon 
Flight season: April

Anax indicus is the the second anax species recorded from Bangladesh. Special thanks to Noppadon Makbun and Pattarawich Dawwrueng, who helped me to identify the species correctly.   


The male

Anax indicus is very similar to Anax guttatus and often confused with the similar species. However, they can be distinguished based on the banding pattern on the labdominal segments. To me, the presence of the fused postjugal yellow band on abdominal segments 6-8 is the easiest key to identify and distinguish the species from A. guttatus. According to Lieftinck (1955), the two pairs of postjugal spots are broadly fused to form a continuous band on 6, 7 & 8. 





Thursday, March 12, 2015

22. Potamarcha congener (Rambur, 1842)

Potamarcha congener (Rambur, 1842)


Number: 22
Family: Libellulidae
Genus: Potamarcha    
Species: Potamarcha congener (Rambur, 1842)
Common name: Yellow-tailed ashy skimmer 
Habitat: Lakes, ponds, rivers, forest patches
Distribution: All over Bangladesh
Abundance: Common 
Flight season: February - November

Potamarcha congener is one the most common dragonfly of Bangladesh, found all over the country. Often seen perching on the reeds of the ponds, jungles and even in the villages. 


The male   

The adult males are black yellow in color. Th thorax and the abdominal segments 11-4 are blue, pruinosed. abdominal segments 5-9 has lateral blue stripe, legs and anal appendages are black 



The male has yellow stripe on the dorsal side of the abdominal segments 1-9. 


Female

The females are like juvenile male, however they can be distinguished by the swollen segment 9 and anal appendages. 






Monday, March 9, 2015

21. Brachydiplax farinosa (Krüger, 1902)

Brachydiplax farinosa (Krüger, 1902)


Number: 21
Family: Libellulidae
Genus: Brachydiplax  
Species: Brachydiplax farinosa (Krüger, 1902)
Common name: N/A
Habitat: Lakes and ponds
Distribution: Dhaka, Sylhet, Chittagong 
Abundance: Common 
Flight season: April - November

In Bangladesh, three species of Brachydiplax genus is available. B. chalybea and B. sobrina has been describe in the earlier post. This is the third and last species of the genus.  


                                   Male

The male is very similar to B. sobrina and extremely difficult to distinguish. The head is brownish black, thorax is bluish black. Abdominal segment 1 is blackish, segments 2-7 are white, 8-10 are black, anal appendages are black.



In the field and by photograph the species can be distinguished by the 8-9 antenodal veins which is 7 in case of B. sobrina.  



Thursday, March 5, 2015

20. Brachydiplax sobrina (Rambur, 1842)

 Brachydiplax sobrina (Rambur, 1842)

Number: 20
Family: Libellulidae
Genus: Brachydiplax 
Species: Bracydiplax sobrina (Rambur, 1842)
Common name: Little Blue Marsh Hawk  
Habitat: Lakes, Ponds, Forest patches 
Distribution: Sylhet, Chittagong, Dhaka
Abundance: Common 
Flight Season: February - December



                                                          The male

The juvenile male is yellow and black in color. The male is dorsally black with yellow lateral spots. 
  

Dorsal view of Brachydiplax sobrina young male

As the male become mature, it starts to change its color, particularly the color of abdominal segments 3-6 starts to transform into whitish. Segments 7-9 has lateral yellow spots anal appendages black. 


Lateral view of Brachydiplax sobrina, immature male
As male become more mature the segments 3-6 turn into bluish and the 7-10 turn into black.


The fully mature male is black and white in color. The thorax is pruinosed, abdominal segments 1-6 are white, 7-10 are black in color.   


Brachydiplax species is confusing B. sobrina is often confused with B. farinosa. B. sobrina can be identified by counting the presence of 7 antenodal veins which is 8 or more in B. farinosa.




  

Tuesday, March 3, 2015

19. Palpopleura sexmaculata (Fabricius, 1787)

19. Palpopleura sexmaculata (Fabricius, 1787)

Number: 19
Family: Libellulidae
Genus: Palpopleura 
Species: Palpopleura sexmaculata (Fabricius, 1787)
Common name: Blue-tailed Yellow Skimmer, Asian Widow
Habitat: Hilly areas, forest patches and water bodies 
Distribution: Sylhet, Chittagong
Abundance: Common 
Flight Season: February - December


Palpopleura sexmaculata, most likely the smallest dragonflies of Bangladesh, are common in Chittagong and Sylhet. 

The male

The juvenile males can be differentiated from the broad greenish thorasic stripe, which are yellow in the adult.


Dorsal view of Palpopleura sexmaculata juvenile male  

The juvenile males are similar to female, are yellow in color, has white pterostigma. However they can be distinguished by their anal appendages. 
Dorsal view of Palpopleura sexmaculata juvenile male 
The adult male have broad yellow thorasic, the abominal segments are white dorsally which is very prominent can can be used to differentiate from female. The wings are transparent, black stripes present in the wing bases, pterostigma and anal appendages are black  

Dorsal view of Palpopleura sexmaculata adult male 
The female
The females are yellow in color and very similar to juvenile male. They are often found associated with the male. 

Dorsao-lateral view of Palpopleura sexmaculata  female