During a recent Hemlock Woolly Adelgid survey, one of our volunteers found a little yellow blob attached to a hemlock twig. The mass was clearly not HWA, but curiosity prompted me to bring it back to the office for examination. A closer look under the microscope revealed that the blob actually consisted of a powdery fungus encapsulating a dead spider! After a bit of research, I came to suspect that it might be some sort of Cordyceps; a genus of parasitic fungi capable of taking control of an arthropod, thus directing it to navigate to a favorable position for the fungi’s spores to disperse following the host’s imminent death. As the little spores float away, they may attach to other unsuspecting arthropods initiating the process all over again!
If you look closely, you can even see the spider’s eyes!
It looks as though the spider is wearing a hat, but in fact it has been taken over by a fungus.
