On our last field trip, we found developing tree-hugger nests on the host tree, Corymbia tesserllaris. Tree-hugger nests look different to ground nests, they form a leathery skin on the tree trunk (see photo below).
Interestingly we found a couple of caterpillars above their nest which is unusual, since they rest inside the nest during the day. One caterpillar had a tachinid fly egg laid on its head (see photo below). Tachinid flies are parasitoids of processionary caterpillars, to read more about them click here.