Monday, September 03, 2012

How many shieldbugs make an autumn?

September means that even if we don't want to admit that autumn is here, it's certainly on its way. Autumn can be a good time to spot some of our native invertebrates though-dragonfly numbers are peaking and adult shieldbugs can be quite numerous, including Sloe Bugs, Forest Bugs, the tree dwelling 'Troilus luridus' and the ever present Green Shieldbug.

One of the smaller shieldbugs that seem to be quite numerous around early autumn time, is the Birch Shieldbug (Elasmostethus interstinctus) and both the nymphs and adults are quite striking...



Click on any photo for a larger view



I think these two pictures above show what are probably 3rd instar nymphs of the Birch Shieldbug. They were quite small and reasonably fast moving.


A slightly larger nymph

A final instar nymph
All of the nymphs featured here were found in the same spot, a birch tree beside a local pond. Some were underneath the leaves and others quite easy to spot against the darker upper-side of a leaf.

There were also a number of the adult insects on the same tree...

The adult

As you can see, they are very colourful little bugs. These shots have not been enhanced in any way either; it was a dull day and had been raining before I took these photos, hence the sheen some of them have but other than reducing the size to upload to the blog, this is exactly how they looked.

The birch tree in question seemed to have a thriving little shieldbug community as I also found a couple of parent bugs as well...

A Parent Bug

I shouldn't have been surprised I suppose at finding this bug-after all, it is associated with birch as well. Once again these are beautifully coloured bugs and like the green shieldbugs, hibernate through the winter months.

This one may be lucky to make it to winter, as those white spots on it's back are parasites. I've seen this species with the same parasite before and I think they are Tachinid fly parasites:they are laid in this position where it is almost impossible for the bug to remove them.

The parent bug gets its name from the females habit of sitting on her eggs and nymphs to protect them from parasites and I've often wondered if she has become the target rather than her offspring?





Troilus luridus
Troilus luridus is another tree dwelling shieldbug and is quite a bit larger than both the birch and parent bugs. It is also a predatory bug, rather than feeding on plants.


This photo shows a final instar Troilus luridus nymph feeding on a large caterpillar. I watched this take place and the caterpillar had no chance of escape-it was busy feeding when the nymph sidled up to it and inserted its proboscis before the larva could do anything at all;although, even given time, I'm not sure what it could have done?

Those then are some of the recent shieldbugs that I've found whilst out walking locally-in case you are thinking of trying to locate some for yourself, here's a snap of the tree and habitat where I found most of mine...


Until the next time then...

All photos in this blog entry taken with the 100mm macro leans and natural light only-I used my Canon 40d camera.

3 comments:

  1. Beautiful photos and interesting info too! Been looking for Troilus everywhere but no luck so far! Liking the new look to the Blog too! :-)
    Maria

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  2. Thanks Maria. I have been lucky with the troilus nymphs this year, in fact I found another just today (on bramble, if it helps?) The new look to the blog came about when it malfunctioned and I took the opportunity to have a fresh look when I got it up and running again-glad you like it...

    ReplyDelete
  3. Some fantastic images in this blog entry John. Liking the new style too my friend.

    ReplyDelete

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