Ted MacRae at Beetles in the Bush once complained that my Challenges are too tough, but his Close Crop Challenges are even worse, IMEO (in my exalted opinion). Well, I just took the plunge at his latest Challenge, so anyone misguessing here can laugh at my answer there. It’s all part of the learning process and the more we learn, the less mistakes we will make in the future (or at least this is the theory).
So far, the fearless Kaitlin has been the only one to venture a guess. Her logic is impeccable, but the premise is false. Given the miserably blurry picture of the larva, that isn’t too surprising. I think I will give this one away and show the adults associated with the mitey larva. I may be making a false assumption here too – the larvae and adults occurred together in the rotting mushroom, but that is only weak inference.
Pygmephoridae is a good guess for the mite, this is a member of the Heterostigmatina, so one point for Kaitlin, but not of the Pygmephoroidea. All the pygmephoroids that I am familiar with have a more or less distinct gnathosoma, but this mite seems very withdrawn. Here’s a hint – these mites will not harm the larva, but bode ill for its future fitness. At the head of the post is a mite related to the Challenge mite, once it belonged to the same genus, but now it does not. Below is the actual mite itself.