Parasitoids reared from a stick insect egg mass in Sarawak (Hymenoptera: Ichneumonidae and Torymidae), with a new species of <i>Palpostilpnus</i> and a new host association for <i>Rhynchoticida</i>

New host associations are documented for two species of Hymenoptera. Both are egg parasitoids and were reared from the same egg mass of a stick insect in Gunung Mulu National Park (Sarawak, Malaysia). The phasmid egg mass is tentatively identified as the previously undocumented eggs of Loxopsis delfossei Seow-Choen. The egg mass offers new information on the infrequently documented parasitoids of phasmids, and the unique morphological features of the eggs are discussed. Palpostilpnus mulu Broad sp. n. (Ichneumonidae: Phygadeuontinae) is described as new and Rhynchoticida ovivora Bouček is reported for the first time from Borneo, with clarification of its host. Egg parasitoids of Phasmatodea are reviewed in light of these findings, and the egg morphology of Phasmatodea is discussed as adaptations against parasitism. This report of new egg–parasitoid associations provides insights into the ecological relationships between stick insects and hymenopteran parasitoids.http://www.zoobank.org/urn:lsid:zoobank.org:pub:23559928-F298-49C1-A076-916B884E234D