Mursley - fooled by a fungi'd fly

Sorry this is not a moths post - nothing interesting in the trap this morning. I don't think the BMERC e-group is still running, so thought I'd try this group.

I fished this fly out of the bottom of my moth trap this morning and thought I'd found something rather special. I pored over my insect books and looked online as it had such striking transverse black and white stripes, but to no avail. Eventually I looked at it under the microscope and realised that the white fluffy stripes are some kind of fungal growth. I'm assuming the fungus has developed and spread around the abdomen following some patterning that was there already. Not sure whether I should show it to a dipterist or a mycologist!

...[2 hours later] OK, now tracked it down -  Entomophthora muscae. (I'm sure you all knew that!) What amazing behaviour: The mycelium of the fungus can grow into an area of the brain that controls the behaviour of the fly, forcing it to land on a surface and crawl upwards. Hyphae gradually grow through the whole of the body, digesting the guts, and the fly dies in about five to seven days.  Once critically ill, the fly tends to crawl to a high point, straighten its hind legs and open its wings, a behaviour that ensures that the fungal spores are dispersed as widely as possible to infect other flies.


Mick Jones