Thanks to Marcus for the initial sighting of this Longhorn beetle with an infection which may have been Puppeteer Fungus. The fungus had erupted from the beetle's joints in a similar manner to Puppeteer Fungus, but the spores hadn't sprayed out onto the adjacent foliage as previously seen with Puppeteer Fungus.
Entomophthora sp. (genus) attacks flies. But there is a similar fungus that attacks beetles- Erynia sp. (genus). See an example of Erynia nebriae at: https://www.flickr.com/photos/westgpottery/49169577782