Leaf tying caterpillars and leaf quality affect arthropod community structure and diversity on white oak trees
A cocoon of a butterfly from the family Nymphalidae.
Leaf tying caterpillars are ecosystem engineers that build shelters that provide habitat for other arthropods like moths, flies, beetles, and thrips. However, there has been no studies of the impact of leaf traits on caterpillars and arthropods. Scientists studied leaf tying caterpillars on white oak trees in Missouri, U.S. and found that quality of foliage and ecosystem engineering by leaf tying caterpillars both determine community structure of arthropods.
To do this, scientists removed and recorded all leaf tying caterpillars and collected leaf quality data on 75 white oak saplings in June and July, followed by an arthropod census in late summer. Removal of leaf tying caterpillars had no impact on overall arthropod species richness, but reduced species diversity and overall arthropod abundance, and changed the structure of the arthropod community as the season progressed.
Total arthropod and caterpillar density was affected by leaf quality, specifically foliar tannin and nitrogen concentrations, and leaf water content. The engineering effect of leaf tying caterpillars was greatest on low quality plants, consistent with the Stress-Gradient Hypothesis.