spider caught a spider hunter !

[Rambling Rob]

Hello,

Sorry the pic isn't very clear, but is there any chance of identifying this spider?

Yesterday, at Yaverland, IoW, I had been watching a pair of black wasps which I think are the spider hunter Anoplius nigerrimus running in and out of burrows, presumably looking for spiders, when one wasp emerged not dragging a spider but in the jaws of a spider. The spider hurried away with the wasp held up in the air, gripped by the head! As it ran and tumbled through the vegetation the photography was hit and miss - mostly miss!



Thanks for looking,
Rob

[Geoff F]

I would suspect that the spider was one of the Crab Spiders (Thomisidae family) possible one of the Xysticus species but they are difficult enough to attempt an identification from a perfect image.

Crab spiders are quite common at this time of the year and do lie in wait, hidden by their camoflage colouration, for some unsuspecting insect to come close.

Impossible to tell if that is a Pompilid wasp from your photo as there are quite a few species which dig burrows like that. Some use caterpillars and other bugs to stock their nests.

As a rough guide; Spider Hunting Wasps have long legs with the hide leg stretching beyond the abdomen. Well beyond it with the tibia being around the abdomen length in most species. Also look for a sharp spur on the hind tibia. But, as usual, there are exceptions.

[No.9 Spider]

The abdomen of the spider is similar in shape to a Tegenaria sp., or possibly a Lycosidae sp. or something else along those lines, the Crab spiders having flatter abdomens, and not being very agile to the extent where they could run thru' the grass as described. Any more photo's from above?





No.9 Spider

[Rambling Rob]

Thanks for the thoughts and info Geoff and Spider No 9.

Two more hugely cropped pics of the encounter:





The spider was running along pretty fast, also tumbling down small slopes/ leaves then regaining its feet to continue.

Rob

[No.9 Spider]

Carapace has the look of a Lycosidae (Wolf Spider) though the side of the abdomen has look of poorly marked Tegenaria. Unfortunately on this borrowed laptop I've got no program to enlarge the photo for a better look.

Are you sure that the aggressor was in fact the spider? as from what I can see (leg contacts to ground and general positions) and from the description of movement and the fact they were mobile tells me that the wasp was the victor carrying the spider to a predetermined nearby lair. A free roaming spider (hunting type) would not do this.



No.9 Spider

[Rambling Rob]

Hi No 9 Spider,

The spider was definitely doing the carrying with the wasp in the air for most of the way - these pics were all that were recognisable from those taken over a distance of about a metre before it disappeared from view. The combo tumbled about a bit so legs in contact with the ground from these snaps may misprepresent.

That said, I now think I have misread the situation, as you suggest.

Jason Green has suggested the wasp might already have delivered a fatal dose to the spider and is simply biding its time for the poison to take effect, and Jaguarondi has noticed it is the wasp which has the spider in its grip.

Appearances are deceptive - a good thing I'm not giving evidence on this in court!

Thanks again,
Rob

[Geoff F]

Yes those photos do suggest that it was the wasp which was dragging the spider and not the other way around. They can drag a spider, which is considerably bigger than them, along the ground at remarkable speed. They use their wings and jump around a bit so they can have all feet off the ground yet still be the one in charge.

Those leg views certainly look like a pompilid wasp. A. nigerrimus would be a good guess but it will be impossible to be absolutely certain from those photos.

And the spider abdomen does look like a lycosidae species, which is a favourite prey.