The effect of mycorrhizae and competition on plant damage and
herbivore performance
There was an interaction between competition and mycorrhizae such that
cabbage looper caterpillars consumed more plant tissue from mycorrhizal
associated plants than non-mycorrhizal plants, but only when the plant
was not experiencing competition. When the plants were grown in
competition, mycorrhizae had no effect on herbivore consumption (Fig. 1,
F1,31=6.28, p=0.018). Cabbage looper caterpillars on
mycorrhizal plants were marginally heavier than those reared on non-
mycorrhizal plants (F1,46=2.9620, p=0.091), but there
was no effect of competition on caterpillar mass
(F1,46<0.001, p=0.996). While induction
increased defensive protease inhibitors (F1,148=9.55,
p=0.002), it had no effect on amount of leaf tissue caterpillars
consumed (F1,42=0.262, p=0.611), or their mass
(F1,42=0.324, p=0.572).