Cocooning In June

The year is racing by and photos I'd put aside for a moment are now a month out of date!  No less interesting though and now seems a good time to bring out this photograph of an Ichneumon Wasp's cocoon (probably campoplegine).  I had no idea what was in the cocoon until this morning, when David Notton, invertebrates expert from the Natural History Museum, helped me out on iSpot.

The Ichneumon's cocoon is the white bit that looks like a bird dropping (possibly to put off predators).  The dried wrinkled skin above is the remainder of the caterpillar it parasitised.  A happy coincidence that I should get this id just after posting the egg-laying Ichneumon video.

Also from June are these two photos showing weevil pupa inside intricately woven cocoons.  These are likely to be from the Curculionidae family -  'True Weevils' or 'Snout Beetles'.

I find cocoons and what's going on inside them absolutely fascinating.

Video Of Ichneumon Wasp Laying Eggs

 I was in the garden this evening, taking down the washing, when this Ichneumon Wasp caught my eye.  Needless to say, I flung the washing at the basket and ran indoors for my camera.  

Ichneumon wasps are parasitic; laying their eggs on, near or inside the larvae of other insects or spiders.  She will detect the larvae by the smell of their droppings and by sensing vibrations in the wood with her antennae.  I was incredibly lucky to have caught this female just as she was driving her long ovipositor into an old branch to lay her eggs in the crack.

You can see her walk up and down the wood, carefully laying one egg after another.  The long black sheath used to protect the ovipositor when not in use, helps her to balance.  When the eggs hatch, they will consume the host.  They will overwinter in the wood and pupate in the spring before emerging. 

Update (13/7/12) - David Notton at iSpot has given me a possible id for this ichneumon wasp of Ephialtes manifestator.  (Thanks David)

Parasitoid Wasp (Perilampidae)

This tiny wasp, about 3mm long, has been making itself at home in our back garden.  The first time I saw it, it was hanging on to a garlic mustard leaf during the high winds of last week.  As the wind blew, the leaf flung the wasp about, flashing the brilliant red/gold of it's thorax.

My thanks to an expert at iSpot who says this is likely to be a parasitic wasp, Perilampidae.

In this species, the larva rather than the egg-laying female gains access to a host; once there, it continues to burrow into a secondary host - another parasite fly or wasp larva.  It makes me think of those wooden Russian dolls, that when taken apart reveal another smaller one, which when taken apart reveals another one, and so on.

As far as I can work out, these incredible looking wasps are not common in the UK.  It's rather special, and each time I see it I have to run for my camera.

If anyone knows more about these little wasps, I'd love to hear about it.