Oviposition of a schnura senegalensis

Last Updated on Monday, 30 November, 2020 11:29:23 PM

INDEX > Damselflies of Borneo > Family Coenagrionidae > Ischnura senegalensis 水田嬰(青紋細蟌) > Oviposition of a schnura senegalensis

Oviposition of a schnura senegalensis (Rambur, 1842) 水田婴(青纹细蟌)

Dragonflies and damselflies need wetland environment with dry twigs and fallen leaves, a mud layer, aquatic plants, and surrounding woodland with reliable supply of water, giving them places to climb, hide, feed, lay their eggs, and grow.

The larvae live in the water and breathe by means of gills carried on three tail projections at the tip of the abdomen. Like adults, the nymphs are carnivores and hunt for aquatic food, small worms, and the larvae of other insects. They have a specially adapted set of mouthparts called the mask. It is normally kept folded under the head, but can be extended with great speed, effectively spearing the victim on the terminal claw like extensions. >

Egg-parasitoids wasps of Ischnura senegalensis
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At 05:05 PM I spotted this Ischnura senegalensis oviposition on a grass stem out of water. Her abdomen is nipping on the grass stem in the water like a worm eating a piece of leave bit by bit.

青纹细蟌豆娘產卵時，先停在臨水的植物上，再慢慢往下爬，將卵產至可浸在水裡的植物上

The next moment a second female damselfly landed on the other side and started egg laying. The first female show no sign of objection.

This second female was the same species and did exactly the same as the first. As the second female's abdomen gradually reaching down for new location for eggs, both abdomen came slowly near.

As if the place for oviposition was too congested, the second female flew away leaving the first in peace.

The first female remain at the same location but shift to the right side as if the location at left was already saturated and moved to the right for new area. Using her sharp ovipositor to cut open the plant materials, this female lay eggs into the plants

Gradually her abdomen reach further down and down the water lave while her abdomen non stop nipping on the stem.

A stem section of a grass with almost hundred eggs from 2 female damselflies laid in 3 minutes.

The female damselfly dipped the tip of her abdomen in the water to touch a soft and suitable part of the water plant.

She makes a small cut with her egg-laying appendage and deposits her eggs in the plant tissue. The eggs hatch into an aquatic larvae known as nymphs.
Like many other damselflies, this Ischnura senegalensis female cut narrow slits into plants and insert her eggs into them. This is an intelligent foolproof protection of the pool being dry up or the eggs being eaten by predators.