Thursday, May 31, 2012

When is a ladybird not a ladybird?

Back in January of this year I found a false ladybird larva that was sitting out the winter months under some loose bark.



In fact there was quite an aggregation/congregation? Not sure what a number of these would be correctly called-anyhow, as there must have been about 20+ and this was a species that I'd not seen much of previously:actually, just the one adult beetle until finding these, I wanted to learn more about them and so hatched a plan to take a few individuals home with me to observe.

I set up a tank with some of the bark removed from the site where I found the larvae and made the habitat as realistic as possible.
They all seemed to pass the remainder of the winter O.K. and whenever I checked on them, there didn't appear to be much movement at all.

Then on the 29th of April, the first of the larvae became a pupa..


I'd read about these pupae being pink but was still shocked at the actual colouration when seen first-hand. Totally different to the ladybird pupae in both colour and form and looking more like something you'd find on the sea bed?

Within a couple of days the others had also pupated. I began to wonder how long this stage would last: I knew that most ladybird pupae remain in this stage for only around a week or so.Would these be similar? After all, they are not ladybirds at all but a beetle pretending to be a ladybird.

The other thing to consider of course was, would the somewhat artificial conditions I was keeping them in affect the whole process?

A week passed with no signs of emergence. Another week...the same result.
As we approached the end of week three, I began to wonder if the habitat I'd provided was lacking something and this would be as far as they got.
I knew that some pupae will raise themselves up on occasions and so I watched for any signs of movement, but nothing!

Then, on the 20th of May, a full 3 weeks after pupation, an adult beetle emerged...




These photos were taken just seconds after it had struggled free of the pupa and it was very pale and lacking any of the markings of a mature false-ladybird beetle at this stage.

The remainder of the tribe emerged within 2 days of the first one.I noticed on one particular pupa, where the underside was visible that just prior to emergence, what looked like wings became visible...

Pupa almost 'cooked'

One of the later emerged beetles
Now that I had a complete set of recently emerged beetles, the next stage would be to see just how long it would take for the spots/markings to emerge.
Again, having watched ladybirds go through this process, I knew that they would get their spots and true colour within hours, or at least by the following day:would these be the same? Would there be a correlation between the species during this stage?

There wasn't any real change during the first few hours, in fact for the rest of the day they remained pink and teneral looking.
However, by the following morning there had been quite a transformation as the 4 dark spots that identify this little beetle were now clearly visible...


But....I was expecting the elytra (wing casing) by this stage to have the fantastic orange/red colour of the mature adults. When would the next change come?

Answer: The next day? No...following day? Nope...Day after? Nah! "Well, when then?" It took another four days in total before they began to colour- up.


Three days later I took the following shot to add to the other reference shots...


And so finally, almost exactly (can you have almost exactly?) a month to the day since emergence, they were ready to be released. I plan to take them to the (marked) spot where I found them way back in January and release them later today.

I've learned a whole lot about this species just from keeping and observing a few individuals-no harm has come to them, in fact they probably had a better time with me than braving the last few months of awful weather.

That's it until the next update!

Until the next time then....

5 comments:

Anonymous said...

Absolutely brilliant JJ! So interesting and informative! Would never have thought it would have taken quite so long to get the spots and also to 'colour up'! Fascinating and beautifully illustrated as ever! :-)
Maria (Rockwolf)

Anonymous said...

Fantastic blog JJ. I learn more from your blogs than i have from any book.They're a beautiful beetle. Never seen one before. Keep up the good work. Derek Cluskey.

nutmeg said...

Fascinating story of larva to adult. Well documented!

JJ said...

Thank-you all so much for taking time to say how you enjoyed this blog entry. I have learned so much from this little experiment.
NB: I apologise for the spelling mistakes/typos too! No excuse, other than it was late in the day when I wrote it :-)I've corrected them now (hopefully).
Thanks again for your interest,
JJ.

Anonymous said...

Fanstastic, I'm growing this beetle right now and I was suprised how hairy the nymph is for a hairless imago !