7-spot ladybird - pupation (series of 8 images)

[Bruce Williams]

I've watched 7-spot (and Harlequin) ladybird pupation several times. I found it to be quite a moving experience and thought some of you might be interested to see a few shots illustrating the emergence of the pupa (I call it stage 1).

To set the scene: The 7-spot ladybird has four larval stages (or instars) getting progressively larger after each larval moult. At the end of the final instar the larva stops eating and attaches itself to a convenient leaf, stem, fence-post or wall and takes up the hunched, head down position shown in the first two images.

Typically it remains like this for around two days. It is fairly still for most of this time however in the last few hours it has intermittent periods of pulsing - occasionally shuddering or lifting itself up. As pupation approaches it swells visibly and the larval skin becomes taut. Suddenly, without warning the skin splits and the pupa (inside) begin to pulse rhythmically, pushing the larval skin back to the point of attachment.

This shedding of larval skin is really just the first stage. During the next few hours the pupa will close up underneath (it is fully open and exposed initially) and the skin will harden and darken and the pupa will acquire its markings.

I have photos showing the remaining stages that I can post depending upon interest.

The first two images show the pre-pupa.



The last six pics chow the pupa emerging as the larval skin is drawn back. This process only takes 2 to 3 minutes so is easily missed.



Bruce

[Bruce Williams]

...thought I'd just add this extra pic.

Ok it's obviously a different 7-spot ladybird however it's just starting to pupate. I was sitting with my eye to the viewfinder waiting for the skin to split and this shot was taken just a second or so after the split first appeared. It takes about 45 seconds to get to the point seen in the first of the 6 original images.

Other interesting observations are the very tight larval skin showing the bright yellow of the pupa inside and noting that even at this very early stage the larval skin has already started to cluster around the point of attachment.



Bruce

[UB4 gardener]

l never realised it was that quick a process. thanks for sharing

Chris

[Bruce Williams]

Yes it is surprising isn't it Chris.

I've clocked up a lot of hours watching pre-pupa and so far have only managed to record (photograph) three 7-spot and two Harlequin pupating.

Here's a pic of a (relatively clean) 4th instar larva of the 7-spot ladybird. You often find them with messy heads and grotty first segments. This is because they tend to stick their heads right inside their prey during feeding.



Bruce