Friday, July 08, 2011

Where have all the insects gone?

It does seen to have been a strange year for insects and bugs thus far. I've been saying so since May really and having talked to friends and contacts about their experiences, we all agree that the timing has been very unusual this season.

Early flowers and the hot weather through April/May seems to have confused the insects and following on as it did from a harsh winter, has only added to the problems with for instance, favourite food plants being in-flower too early.

However, nature has a way of sorting these things out and it's not all doom and gloom.
As usually happens, what's negative for one species, becomes a positive for another.
Having been troubled by my lack of invert finds recently, the past few days have seen a real augmentation to numbers with a sudden proliferation of bug and insect eggs and nymphs.

Emerging Ants

I found these tiny ants as they were emerging from the eggs when I moved a stone on a woodland pathway. The adults were very quick to react to being disturbed and immediately began to pick up the youngsters and move them to safety. I replaced the stone having taken this shot of them.

Next up were these little woodlouse nymphs. It struck me on finding these, just how many species emerge in white; I wonder why it seems that so many are pale at this stage and only later get their true colour? After all, we as humans don't usually undergo a colour change as we grow (unless you're Michael Jackson that is).

Juvenile Woodlouse 

The nursery-web spiders have been busy too and if you look in the long grass in almost any meadow at this time of year, you'll probably see a small 'nursery' full of youngsters. Each nursery contains too many spiderlings to count but there will be well over a hundred . 
Nursery-web Spiderlings

Urrrrgh! Spiders! Yes I know there are many of you for whom the mere sight of a photograph of an arachnid is enough to induce a cold sweat. You'll be pleased then that we're about to replace the Urgh! factor with the Ahhh! factor.

A Green Shieldbug Nymph

This miniature bug illustrates nicely my point about an increase in the nymphs that are starting to appear now. Whilst in previous years there have been plentiful supplies of numerous species to record and photograph, until now, they have been a rare sight this year.

This creature (about 4-5mm) is a second instar of the green shieldbug, the first being even smaller and instead of the green seen on this one, would be a kind of pinkish tone.
There are in all 5 instars before it becomes an adult and each one looking quite different to it's predecessor. For instance, take a look at the photo below.

This one is a fourth, or possibly even final instar-nymph and as you can see bears little resemblance to the second instar.

Adult Green Shieldbug

The last photo here shows the adult. This one was taken at the end of last season and it's already in it's winter colours. During the spring and summer it would be green.

Rhagonycha fulva
It's this kind of behaviour that's responsible for the explosion in insect numbers and it'll come as little surprise to you that one of the names this little cantharis beetle has is the 'Hogweed Bonking Beetle' Also referred to as the common red soldier beetle.

My sister, who sometimes accompanies me on my evening or weekend bug-hunts has her own name for it, to her it will always be the 'Bloodsucker'  They do not suck blood of course, and the name seems to have derived purely from their colouration.  And yet....people are still frightened by them and react with waving arms and shouts of "Urgh! One of those bloodsucker things" 

My interest in insects has taught me many things, and a strong contender for top position amongst those would be just how unreasonable most folks act around our insects. The truth is that most will not harm you in anyway and those that look to be the biggest threat are often a harmless critter disguised as a 'killer' as a means of defence against predators.

I suppose I should at this juncture be providing the answer to my little puzzle set in my last blog entry?
I should.....but I don't think I will just yet. 

If you've been wondering (and why would you?) just what the larva of this beetle looks like, then wonder no more as the next photo is just such a thing.
Cantharis Beetle Larva

Not to be confused with this following photograph of a larva. This one is actually the larva of a glow worm. These are fascinating creatures and becoming scarce in some areas. There is a great website dedicated to them where you can read all their lifestyle; including things like, only the female glows and she turns out her light after mating. The glow worm only lives for about 14 days, and other interesting things.

A Glow worm Larva

Finally, another species of shieldbug that has been busy egg-laying in the last couple of weeks is the Woundwort Shieldbug-Eysarcoris venustissimus. With the fully grown adults only managing a paltry 5-7mm, you can perhaps imagine how minute the eggs are and the difficulties of getting reasonable shots of them?

I tried my best to get some photographs as a record of the species and below is the best of the bunch. Not one of my best photos I agree but considering each of the eggs would be not much more than a millimetre across, acceptable.
Perhaps next year I'll try some shots using a reversed prime lens to get closer and bring out more detail.

Woundwort Shieldbug Eggs

I'm keeping an eye on the areas where these were found, as there were quite a number of eggs, and I'll hopefully be able to share with you in a later blog entry pictures of the emerged bugs. The little 'eyes' on these eggs suggest to me that they'll be emerging any day now.

The puzzle then? The photo was of a Burnet Moth pupa. In this case, probably a 6-spot.
They are usually to be found attached to a stem of grass, quite why this one was lying on the ground I'm unsure.
However, all being well it would in time morph into the moth pictured below.

Congratulations if you got the correct answer :)

6-Spot Burnet Moth

Until the next time then....


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