Sample Collection
Samples were collected between October 31st - December 10th, 2018 from Eucalyptus globulus Labill. plantations around Hamilton, Victoria, Australia, owned and operated by Australian Bluegum Plantations (http://www.austgum.com.au/) (Fig. 1) (SI Table 1 & 2). Plantations were chosen to ensure efficient collecting. Another species of Eucalyptus was present as volunteer plants but could not be identified to species due to an absence of reproductive parts (Eucalyptus sp. 1). Beetle larvae between the first and fourth instar were collected by hand and reared gregariously in 750mL plastic takeaway containers, with all beetles collected from a single tree reared in the same takeaway container. Before pupation, beetle larvae were placed into 2cm x 2cm nylon pouches, stapled shut, and isolated in small vials in anticipation ofEadya emergence to establish definitive host-parasitoid associations following Davy et al. (2016). A total of 98 parasitoids were reared from the beetle larvae.
For each beetle and parasitoid collected the GPS coordinates of the tree were recorded. Upon reaching the final instar, the beetle host was isolated before pupation when the parasitoid emerges to establish a definitive parasitoid-host association. Upon emergence of a parasitoid, what was left of the beetle host was immediately stored in 95% ethanol. Parasitoid wasp larvae that emerged and successfully spun cocoons were kept for 50 days, allowing for adult morphological characters to develop, and then preserved in 95% ethanol. Those that failed to exit the host or successfully spin a cocoon were immediately preserved in 95% ethanol. For each beetle larva collection event, three leaf samples were also collected: an herbivore damaged leaf, an undamaged leaf of the same age class as the damaged leaf (either flush (newly expanding) or fully expanded glaucous foliage), and an undamaged leaf of the other age class. Leaves were labeled accordingly and dried in individual plastic sandwich bags with silica desiccating powder.