Data for: Field evidence for the role of plant volatiles induced by caterpillar oral secretion in prey localization by predatory social wasps

One assumed function of herbivore-induced plant volatiles (HIPVs) is to
attract natural enemies of the inducing herbivores. Field evidence for
this is scarce. Also, the assumption that elicitors in oral secretions
that trigger the volatile emissions are essential for the attraction of
natural enemies has not yet been demonstrated under field conditions.
After observing predatory social wasps removing caterpillars from maize
plants, we hypothesized that these wasps use HIPVs to locate their prey.
To test this, we conducted an experiment that simultaneously explored the
importance of caterpillar oral secretions in the interaction. Spodoptera
caterpillars pinned onto mechanically damaged plants treated with oral
secretion were more likely to be attacked by wasps compared to
caterpillars on plants that were only mechanically wounded. Both of the
latter treatments were considerably more attractive than plants only
treated with oral secretion or left untreated. Subsequent analyses of
headspace volatiles confirmed differences in emitted volatiles that likely
account for the differential predation across treatments. These findings
highlight the importance of HIPVs in prey localization by social wasps,
hitherto underappreciated potential biocontrol agents, and provide
evidence for the role that elicitors play in inducing attractive odor
blends.