Friday, October 31, 2014

08. Brachythemis contaminata (Fabricius, 1793)

Brachythemis contaminata (Fabricius, 1793)

Number: 08
Family: Libellulidae
Genus: Brachythemis  
Species: Brachythemis contaminata (Fabricius, 1793)
Common name: Ditch jewel
Habitat: Lakes and ponds, riverside  
Distribution: Dhaka, Sylhet, Chittagong 
Abundance: Common 
Flight season: April - November

This beautiful dragonflies is one of the most abundant dragonfly of Bangladesh. They lived in good numbers nearby ponds and water bodies.  

                                    Male

Length of the abdomen ranges from 21.0-23 mm, red colored. The head is brown, wings transparent, reddish amber extends over the nodal area, pterostigma red. Legs black. Abdominal segments are red, black dorsal stripe present in the abdominal segments. Caudal appendages reddish.     






Female



Females are similar in size and shape of male, bright colored. Unlike male their wings are completely transparent, pterostigma yellow. Bold, black dorsal stripe present throughout the abdomen. Female can be easily identified by their distinguished anal appendages.  


Tuesday, October 21, 2014

07. Aethriamanta brevipennis (Rambur, 1842)

Aethriamanta brevipennis (Rambur, 1842)                                                                         
Number: 07
Family: Libellulidae
Genus: Aethriamanta brevipennis
Species: Aethriamanta brevipennis (Rambur, 1842)
Common name: Scarlet Marsh Hawk
Habitat: Lakes and ponds  
Distribution: Dhaka, Sylhet, Chittagong 
Abundance: Not very common 
Flight season: May- September

                                                                    Male

The young male of the species are yellow. like the female of the species. However can be separated from the female by observing the anal appendages also the black ring in the  abdomen is absent in the young male.  


The adult males are red. Eyes are brown, legs are black, thorax is dark chocolate brown. Wings are transparent, deep amber present at base, pterostigma black. Abdomen deep red, segments 4-6 contain black dorsal spot. Anal appendages red.    


Female 

Females are yellow, green eye with brown capped above. Thorax and abdominal segments are yellow, black ring present in the abdominal segments which helps to distinguish females from young male.    



Monday, October 20, 2014

06. Agriocnemis pieris (Laidlaw, 1919)

Agriocnemis pieris (Laidlaw, 1919)
Number: 06
Family: Coenagrionidae
Genus:  Agriocnemis 
Species:  Agriocnemis pieris (Laidlaw, 1919)
Common name: White dartlet
Habitat: Ponds, lakes, riversides associated grassland   
Distribution: Dhaka, Sylhet, Chittagong 
Abundance: Common 
Flight season: March- October
Similar species: Agriocnemis lecteola

Agriocnemis pieris, one of the smallest damselfly of Bangladesh, is a closely similar species of Agriocnemis lecteola and often overlooked. This is my fifth Agriocnemis species from Bangladesh. 

                             Male

The males are white and pale blue. Length of the abdomen and hind wing is 16-18 mm and 11-12 mm respectively. The head is green and black capped, legs are white with black spine. The prothorax is black, anterior of the prothorax is green. 

Fig: Agriocnemis Pieris, male (lateral view) 
Thorax is dorsally black, laterally pale blue with green antehumeral stripe. Abdominal segments and anal appendages are white. Segments 1 and 2 contain similar black scratches dorsally, segments 3-6 contain black dot and segment 7 with distinct black scratch, by which the species can be distinguished easily from Agriocnemis lecteola. 
    


Fig: Agriocnemis Pieris, male (dorsal view)
Fig: Agriocnemis Pieris, teneral male (lateral view) 



The females are often seen associated with male, green and black stripped slander damselfly. Very much confusing with A. lecteola female.




Fig: Agriocnemis Pieris, female (lateral view) 
  

Wednesday, October 15, 2014

05. Agriocnemis Lecteola (Selys, 1877)

Agriocnemis Lecteola (Selys, 1877)
Number: 05
Family: Coenagrionidae
Genus:  Agriocnemis 
Species:  Agriocnemis Lecteola (Selys, 1877)
Common name: Milky dartlet
Habitat: Ponds, lakes, riversides associated grassland   
Distribution: Dhaka, Sylhet, Chittagong 
Abundance: Common 
Flight season: March- October
Similar species: Agriocnemis pieris

Agriocnemis Lecteola is fourth Agriocnemis species captured my me. This is a tiny damselflies like other Agriocnemis species. The species is close similar to Agriocnemis pieris and often cumbersome to differentiate.

Male

This is most likely to be the newly emerged male specimen. Eyes are green, brownish capped. Prothorax brownish. Thorax is brownish with white antehumeral stripe. Abdominal segments and caudal appendages are white.


Eyes are green, black capped. post ocular spot green.Wings hyaline, pterostigma black in the fore wing and pale blue in hind wing. Legs white with black spine. Legs are white with black spine. Prothorax black, Thorax dorsally black, yellow antehumeral stripe present and laterally white. Abdominal segments are white, black spots present in abdominal segments 1-3, segments 4-10 and caudal appendages are white. 


Female

The females are often seen perching with male in the grassland. The eyes are green, black capped, blue postocular spot present. Prothorax and thorax is black, green antehumeral spot present, thorax laterally greenish. Abdominal segments 1-9 laterally blue, dorsally black, abdominal segments 10 is completely black. Anal appendages are blue.  




04.Agriocnemis kalinga (Nair & Subramanian, 2014)

Agriocnemis Kalinga (Nair & Subramanian, 2014)
Number: 04
Family: Coenagrionidae
Genus:  Agriocnemis 
Species:  Agriocnemis kalinga (Nair & Subramanian, 2014)   
Common name(s): N/A
Habitat: Ponds, lakes, riversides   
Distribution: Dhaka, Sylhet, Chittagong 
Abundance: Common 
Flight season: January- October
Similar species: Agriocnemis femina, Agriocnemis pygmaea, Agriocnemis keralensis

Agriocnemis kalinga often found associated with Agriocnemis femina and Agriocnemis pygmaea. All the species are morphologicallly similar and availability in same area makes it often difficult to distinguish. 
Male   

 Agriocnemis kalinga is a tiny green damselflies. Length of the abdomen is 13-14 mm and length of the hind wing 9-10 mm. Head is apple green with black cap above. Thorax is black, green antehumeral stripe and laterally green. Legs are yellowish, outer side of femora is black.   


Wings are transparent, pterostigma yellow. The male is different from the other two similar species (Agriocnemis femina and Agriocnemis pygmaea) having a green rounded spot in abdominal segment 2. Abdominal segment 1 is green, segment 3-7 are laterally green, dosally black, segment 8-10 are laterally and ventrally yellow, dorsally black. Caudal appendages are yellow.   


Female

The female is apple green in color, remain in close association of the male. the color of the juvenile female varies from green to yellow. Eyes are green, black capped. Wings are transparent, greenish pterostigma. Legs are whitish with black spine. Thorax is greenish, abdomen yellowish.  





  


   




03. Agriocnemis pygmaea (Rambur, 1842)

Agriocnemis pygmaea (Rambur, 1868)
Number: 03
Family: Coenagrionidae
Genus:  Agriocnemis 
Species:  Agriocnemis pygmaea (Rambur, 1842)
Common name(s): Pygmy dartlet, Pygmy wisp
Habitat: Ponds, lakes, rivers associated grassland   
Distribution: Dhaka, Sylhet, Chittagong 
Abundance: Common 
Flight season: All seasons of the year
Similar species: Agriocnemis femina, Agriocnemis pygmaea 

Agriocnemis pygmaea, a closely similar species of Agriocnemis femina, is a small damselflies often found in the grassland associated to water bodies. They are tiny, maintain small territory, stay close to ground and flight slowly within a short range. Due to their small size often they become prey of many other damselfles and dragonflies. 


Male     

Agriocnemis pygmaea is morphologically similar to Agriocnemis femina. The length of the abdomen is 16-17 mm and the length of the hind wing is 9-10 mm. The eyes are green, black capped, post ocular spot present. Thorax is black dorsally marked with apple green antehumeral stripes and green laterally. Legs are whitish. Wings are transparent, Pterostigma pale yellow in the fore wing, black in the hind wing, 6-7 post nodal vein in the fore wing 5-6 in the hind wing.   
     

Black stripe travels from segment 1 to segment 7 dorsally, pale yellow laterally, segment 1 and ventrally green. Segment 8-10 and caudal appendages orange.  


Female
Like many other female damselflies Agriocnemis pygmaea shows different color morphs, mainly red morph and green morph. Eyes are pale green, brownish cap above. Broad black stripe in the thorax, associated with adjacent thin bluish stripe. Legs are whitish with black spines. 


Wings are transparent with golden pterostigma.  Abdominal segments are red, with apical black ring in segment 2-6. Abdominal segments 7-10 are dorsally black, Caudal appendages are red.


In green form blue post ocular spot are visible. The antehumeral stripes are blue, thorax is laterally green. The abdominal segments are dorsally black and laterally green. 


Both the red and green morph are seen in matting. They usually perched from the grass while matting. Matting lasts for a few minutes.


Distinguishing A. femina from A. pygmaea is very difficult, however by close comparison of the anal appendages it can be done. 


 


     
    

Monday, October 13, 2014

02. Agriocnemis femina (Brauer, 1868)

Agriocnemis femina (Brauer, 1868)

Number: 02
Family: Coenagrionidae
Genus:  Agriocnemis 
Species:  Agriocnemis femina (Brauer, 1868)
Common name(s): White-backed wisp, Variable wisp
Habitat: Water body (ponds, lakes, rivers) associated grassland   
Distribution: Sylhet, Chittagong 
Abundance: Common 
Flight season: All over the year
Similar species: Agriocnemis pygmaea, Agriocnemis minima 


Agriocnemis are the smallest damselflies of Bangladesh. A. femina shows different color variation in different developmental stages, this is why they are often called variable wisp. They are common however, due to their small size and difficulties to differentiate from A. pygmaea, they are often overlooked.    

                                                Male
  
The male damselfly is a tiny one. The short abdomen measured 16-17 mm. Eyes of the damselflies is green with black capped above, blue or green post ocular spot present. Legs are pale yellow, the external side of the femora is black. The dorsum of the thorax blak with green or blue antehumeral stripe, that extends to the prothorax. Hind wing length 10-11 mm, wings are clear, pterostigma black. Abdominal segments are dorsally black , laterally blue or green. Anal appendages are orange. Below is a male with segment 8-10 dorsally black and orange ring in the apex of the segment.    



The damselflies has two morph mainly, the blue morph and green morph. In blue morph, the antehumeral stripes, post ocular spots and lateral portion of the abdominal segments are blue. Abdominal segment 8-10 are completely orange.



The antehumeral stripes, post ocular spots and lateral portion of the segments are green, in green morph. Segment 8 black dorsally, yellow ventrally, segement 9 and 10 are yellow as well as anal appendages.


The pruinosed male of the species can be identified easily. As the male gets older, their thorax gets pruinosed.    




                                               Female


The females of the species are difficult to identify. The female has two forms, red form and green form. The eyes are green, black cap above, no post ocular spot. Anterior lobe of the prothorax has a black spot, posterior lobe is large and elevated. Legs are whitish with black spine. Broad black stripe in the thorax, no clear antehumeral stripe. The wings are clear, yellow pterostigma. Abdominal segement 1-6 are red, broad black dorsal stripe present in segments 7-10.   

         

I have photographed a female specimen which I believe is the intermediate form between the red morph and green morph. The antehumeral stripes are brick red, lateral portion of the thorax is turning into blue. Abdominal segments are yellow laterally. 


The andromorph female is similar to male, the antehumeral black stripe absent and the terminal anal appendages are different,

  

I have documented a few matting pair of A. femina. Presented one is from Sylhet. In 12th October afternoon I spotted the pair from SUST campus. The male was not pruinosed and the female was the green form.


The copula with andromorph female, I have sighted from SUST campus at 19 May, 2015



It is very difficult to differentiate A. femina from A. pygmaea because they are very similar. Moreover, most often both species share the same microhabitat which makes it even more difficult. The best and simplest way to differentiate is by examining the anal appendages of the male specimen which are quiet different. The females are even more difficult to identify, however by close examining of the prothorax they can be differentiated. Finding a niche that contain either one of the species is an excellent way to study them. In Narsingdi, I found A. pygmaea only which makes it easy to monitor and study.    

01. Acisoma Panorpoides (Rambur, 1842)

Acisoma Panorpoides (Rambur, 1842)                                                                          
Number: 01
Family: Libellulidae
Genus:  Acisoma
Species:  Acisoma Panorpoides (Rambur, 1842)
Common name(s): Trumpet tail
Habitat: Lakes and ponds  
Distribution: Dhaka, Sylhet, Chittagong 
Abundance: Not very common 
Flight season: March- October

This little but enchanting dragonfly of Libellulidae family love to stay in close proximity of water bodies. They are often sighted perching on the reeds of ponds and lakes. 

Male  

The males are small with abdomen length of 15-18 mm. The length of the hind wing are 16-21 mm. The face  is of pale blue color, eyes are blue. Legs are black. Wings are transparent and hyaline with pale yellow pterostigma. Thorax is blue with numerous black spots dorsally and laterally. Abdomen is blue, segment 1-5 are widely dilated whereas 6-10 are precipitously slim and slender. Segment 1-7 are dorsally black and laterally blue. Segment 8-10 are black. Caudal appendages are white and longer than segment 10.      



                                                Female 

The females are of similar size and shape of male. The females are of yellowish color. The face is yellowish, eyes are green with brown cap. Legs are black, wings transparent with pale yellow wing spot.  Abdominal segment 1-5 are dilated, dorsal black line from 1-7. White lateral line at segment 6 and 7, Segment 8-10 black. Anal Appendages are white and wider in comparison to male.  
   

On 01 April 2015 I have sighted the oviposition of Acisoma Panorpoides at Shahjalal University of Science and Technology campus. In the first photo the male is guarding the female and the latter three the female is lying eggs.