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).