This cricket was clearly suffering. I have no idea what this growth is, and I'd appreciate suggestions.
No interactions present.
Looks like a few sections of an over-ripe blackberry has fallen onto his head to me rather than a growth.
Tachinid Recording Scheme
TRS Facebook Page
I thought of that, but look at the surface of the growth - it's got what looks like veins on it. And in addition, it was firmly attached to the insect. Sorry, Matt.
I've never seen anything like it, but it seemed almost like a tick (but I bet it's not).
I'm actually with Matt here. I think the veins are cracks resulting from contraction as the blob of gloop dried (around a couple of pips?), and it's amazing how hard a bit of partly digested or decayed fruit juice can set - it would be hard to remove it casually, at any rate.
I've seen a fair few fungal infections in insects, but never anything with this form or surface texture, and it's far too irregular to be an ectoparasite. Also, if that's a fungus that's emerged through the head, the host really shouldn't be walking around...
Definitely not a blackberry. The surface was quite smooth, and the veins were not cracks. Nor were the segments separated, or all the same size.
The cricket was suffering quite badly, and the left rear leg seemed hardly to be working at all.
I've sent the details off to the Natural History Museum; maybe they'll come up with something.
A fungus of the Cordyceps type? They infect various species, and change the behaviour, causing them to seek a position advantageous to the dispersal of fungus, before "erupting" to release the spores.
Ithought it mightbe something like a fungus. Maybe I sould re-post it in fungi. Might be an idea. I think I'll try that, and hope to get help from the iSpoters who know more about this sort of stuff.
It could be a herniated part of the insects gut (the veins suggest this). I have seen similar things on injured/diseased orthoptera and stick insects in the past. The organs can become filled with a gas and or liquid (not sure what causes this) and project outside the body significantly.
I've finally heard from the Natural History Museum on this:
I think the 'growth' is extruded gut, protruding from the neck region between head capsule and thorax. The specimen seems to have suffered crush injuries, the abdomen is swollen so the genitalia are protruding abnormally and the right hind tibia looks broken. Very sad!
So, not a blackberry, nor a parasite. Austin22 was the closest. I'm sure Ms Marshall is right.
Lat/Lng: 52.29034, -0.33091
OS grid ref: TL139671