Site Description and Host Plant Selection
I conducted field predation trials at two sites in Ann Arbor, MI,
approximately 4km apart (Bird Hills Nature Area, “Bird Hills”:
42°18’09.1”N 83°45’37.9”W; Nichols Arboretum, “Arboretum”:
42°16’48.9”N 83°43’20.5”W; see supplemental figure 1). Both sites were
composed of mixed coniferous-deciduous forest, and contained host plants
of P. troilus caterpillars such as sassafras (Sassafras
albidum ) and tulip tree (Liriodendron tulipifera ). I selected
individual plants haphazardly across subsites, with at least 5m between
each plant. All plants were checked for P. troilus larvae before
the start of each trial and previously occupied plants (n = 17; see
supplemental figure 1) were not used. Potential predators of P.
troilus were present at the sites throughout the experiment (see
supplemental table 2), as well as live P. troilus larvae and
adults. I ran two predation trials at these sites: Trial 1 (July
3rd to July 12th) and Trial 2 (July
20th to July 30th).