Friday, June 26, 2015

In which Giovanni gets all spiky...

Back in March of this year I came across some shieldbug eggs under bark. I didn't know at the time, but they were later identified as Spiked Shieldbug eggs (Picromerus bidens) and it seemed like a wonderful opportunity to further study the life-cycle of these fascinating bugs.

And so I took some home with me and carefully ensured they were given optimum conditions for the bugs to develop and finally emerge. These are the pictures...

Nothing happened until April 15th of this year when the first nymphs arrived...

These are the tiny nymphs that emerged on April 20th 2015

On April 25th four more emerged. These are redder because I managed to catch them soon after emerging...
April 25th nymphs

By April 29th they had darkened

On the same day, some began to moult for the first time...

April 29th first moult

The next picture is from May 4th...

Unfortunately my sometimes haphazard filing system has resulted in a few pictures going AWOL between these dates, which is really annoying for me as they showed how the nymphs had already begun to become predatory. Instead of feeding on plant sap, they were starting to need more substantial food in the shape of caterpillars etc. Even more upsetting, is the fact that you can bet your bottom dollar no sooner have I published this update without them, than they will miraculously re-appear? 

Anyhow, let's move on to the next stage that I do have,the mid-instars...

May 31st mid-instar nymphs

It was at this stage that I struggled to find enough food for them all and so decided to release them all, apart from one individual that I would hang on to to allow me to complete the whole process in pictures, from egg to adult insect. I called him Giovanni! Giovanni is the Italian equivalent of John-Gift from God. I also understand that Giovanni is a leader in something called 'Pok√©mon' and as he was to become the leader it seemed apt...         

Giovanni in all his glory...

The next picture is from June 1st...

Beginning to show some lovely metallic hues now

June 10th next and these are now late instar nymphs...

June 10th late instar

Starting to show the spiky shoulders that gives this bug it's common name...

June 10th late instar

The final instar nymphs are quite something...

Final instar Spiked Shieldbug Nymph

Final instar Spiked Shieldbug Nymph

Final instar Spiked Shieldbug Nymph

One final moult...

And the cycle is complete...

Giovanni becomes an adult...

In all honesty Giovanni could be female but whatever his sexuality..he/ splendiferous!

This picture (above) shows Giovanni whilst he was still a touch teneral in colour as it was taken soon after the moult. I waited a few hours for him to recover and ensure he was fit for release, and then took him to an area where I often find these shieldbugs and watched as Giovanni wandered off in search of a new home...

The end.

Or is it? Not quite because since tying this up, I have had a lie-down, sat in the Hero Yoga Pose for half an hour, given myself an Indian head-massage, completed a course of cognitive therapy, read a couple of pages of 'Mindfulness' - Finding Peace in a Frantic World, given myself a stiff talking to about losing files and set about re-exploring my satellite drive, whilst all the time concentrating on my breathing and guess what? I have located one of the missing pictures that shows how soon these little bugs become predatory...

Well I certainly learned a whole lot by doing this and I guess it's something I may never have seen otherwise.

Until the next time...


  1. It is interesting to watch this proses, you get to see things happen close up (just raised my first Butterflies from caterpillars ).
    The nymphs are a stunning colour from the red to the metallic and your photos show this of very well.
    Amanda xx

    1. Thanks Amanda. I am pleased you enjoyed seeing the process and well done on your butterflies...

  2. Delightful posting!
    The tenerals are such a vibrant scarlet.
    I've watched them in the wild progress though the instar stages - and found they stayed together - irespective of instar stage (sensible for hunting ? **) - with no dispersal, until they reached the final instar stage when the younger ones appeared to shun their bigger sibling - who then went off to pastures new.
    But from what I've seen, dispersal begins at quite an early stage with Zicrona caerulea the Blue Shieldbug and Troilus luridus the Bronze Shieldbug - other carnivores.

    1. Thank-you Ray. Yes they are, although I daresay enhanced a tad by the flash photography. Yes, I too noticed how they were gregarious, for the time I had them at least. Although they did move around quite a bit in the tank, they did so in groups.

      I don't know about the Blue Shieldbugs as I have sadly found few of those locally over the years. Also have not studied Troilus luridus closely, although maybe I should as they are commonplace here.

  3. I hadn't heard of this bug, but when I got to the end I realise I've seen pics of this one. Brilliant documentation all through the different instars. I wonder if Giovanni got a bit lonely when you released his siblings? I hope you talked to him and kept him company like I did my caterpillars last year. ;-)

    It's also a bit sad the things we have to do in order to remember things once we get to a certain age! But it was worth it for that photo! :-)

    1. Thanks Mandy...yes, of course I spoke to him..told him I was relying on him making it ;-) I probably said other things too but...I forget, you know how it is ;-)

  4. FANTASTIC JJ!!!!!!!! I am SOOOOOOO green! Lol! Would love to find eggs and would also love to be brave enough to rear my own Giovanni to adulthood! Something I hope to do to complete another lifecycle compilation!
    WOW! Stonking series of shots!
    Lots of exclamation marks and capital letters I know, but I'm excited and I'm shouting too!!! ;-)

    1. Hi Maria. Firstly, my apologies for this now appearing earlier. I removed the need to approve posts and so automatically assumed yours would be here, as everyone else's was. I can only think it might be because it is anonymous? I will have to remember to publish myself if it doesn't appear but have been a bit distracted with other commitments lately, you know how it is ;-)

      Anyway, now that it IS here, I want to thank you of course. Also for the other kind comments. I'm sure you could and will do the very same thing one day soon...


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