Kerala Dartlet (Agriocnemis Keralensis Peters, 1981) പത്തിപ്പുല്‍ചിന്നന്‍

കേരളത്തിൽ കണ്ടെത്തിയതിൽവച്ച് ഏറ്റവും ചെറിയ തുമ്പി. പശ്ചിമഘട്ടത്തിലെ സ്ഥാനീയ തുമ്പിയാണ്. ഉദരത്തിലെ രണ്ടാം ഖണ്ഡത്തില്‍ മൂർഖന്റെ പത്തിപോലൊരു അടയാളം ഉള്ളതുകൊണ്ടാണ് ഇതിനു പത്തിപ്പുല്‍ചിന്നന്‍ എന്ന പേരുകിട്ടിയതെന്നു പറയപ്പെടുന്നു. 

Common name: Kerala Dartlet /Kerala wisp
Malayalam name: പത്തിപ്പുല്‍ചിന്നന്‍
Scientific name: Agriocnemis Keralensis Peters, 1981
Family: Coenagrionidae
Place of observation: Thumboor/ Thommana, Kerala
Date of observation: Various
Habitat: Freshwater

Abdomen: 13mm Hind wing 8mm (Male)
Abdomen: 14mm Hind wing 9mm (female)

Identification keys of male: Dark thorax with apple green humeral stripes. Eyes are pale green, banded with thick black stripe. Reddish orange with black markings on the upper side of the abdomen. Legs are bluish-white with black markings and wing spots (Pterostigma) are dull yellow.

Identification keys of female: The upper part of the pale yellow eyes are reddish-orange and blackish-brown thick band connecting the eyes.

Kerala dartlet or Kerala wisp (Agriocnemis Keralensis) is the smallest damselfly found in Kerala and Goa. These are from the family coenagrionidae, the narrowly winged damselflies. It is endemic to the Western Ghats. The abdomen of the male is about 13 mm long and the female is 14 mm long. The hind wing of the male is 8 mm long and the female is 9 mm long. The main habitats are small streams, lakes, ponds and paddy fields with fresh water. It can, therefore, be considered a good indicator of freshwater. They are commonly found in grasslands and marshes near freshwater sources. Indiscriminate pesticide use in fields is a serious threat to their survival. They are found in abundance in Kole wetlands, paddy fields, and freshwater sources in the Thrissur district. I also found a lot in the Thommana, Muriyad, and Thrissur Kole wetlands. Fortunately my village, Thumboor is rich with these little guys. During my eight years of observation, I have never felt that these are endangered.

There are differences in appearance between male and female damselflies. The colour and shape are very similar to the Pygmy dartlet (Agriocnemis pygmaea). But males are easily identified by the cobra hood mark found in the second segment of their abdomen, and it has brown capped green eyes. Females are present in both the green and black common morph and the reddish heteromorph. After mating, lay eggs in freshwater. The eggs hatch and the larvae emerge. They grow and feed on small fish, larvae of mosquitoes and other aquatic insects. The fully matured larvae come out of the water through the aquatic plants. The damselfly breaks the outer shell of the larvae and emerges from it. The crust of empty larvae is called exuviae. When the wings are dry, they fly away.

The hues of the immature damselflies may not be as bright and clear. They get their own beautiful colours in real-time.

These mating pictures are rarely available. One reason may be the lack of size and indistinguishability of the grasses. Fortunately for me, I got to see this rare sight twice.

The damselfly, which has emerged from the larvae, has no identifiable spots or marks.

Inside the red circle is the cobra hood mark that identifies the male damselfly. This mark makes them easily distinguishable from the Pygmy dartlet (Agriocnemis pygmaea).

Normally females are green and black. But there are also a lot of heteromorphs. It is not an easy job for even the experts to distinguish them from the Pygmy dartlet (Agriocnemis pygmaea) and white dartlet (Agriocnemis pieris) females of the same red morph.

Female & male

Male

Female

Male

Male

Mating

Female

Male

Male

The synthorax of male

Female Heteromorph

Anal appendages lateral view

Anal appendages lateral view

Anal appendages lateral view

Anal appendages Dorsal view

Anal appendages Dorsal view

Dorsal view of eyes & thorax of male

Segment 2 & secondary genetalia