4. Discussion
The experimental setting was partially successful as even
though the control and earwig trees had earwigs while banded
trees did not, earwig abundance in the earwig trees was not as high
as in the control trees. Moreover, as the refuges did not contain the
entire earwig population of the canopy, and the number of earwigs
added to the earwig trees was estimated from the number of earwigs
present in the refuges of control trees, earwig population in
earwig trees was even lower in comparison to control trees. Earwig
abundance also varied from year to year: i.e., from April to June –
when earwigs mainly interacted with aphids and flowers – it was
significantly higher in 2009 than in 2010. These differences in earwig
abundance between treatments and years clearly influenced
the results and thus need to be considered in the following
interpretation.