Fooled by fly fungus!!

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 absomen following some patterning that was there already. Intriguing - must check it out with dipterist colleagues.