# Mite Domatia and Associated Mite Density in a North American Eastern Deciduous Forest in Michigan

## TL;DR

This study found that over 80% of woody plants in a Michigan forest have structures housing mites, which are important for plant defenses.

## Contribution

The study provides the highest reported percentage of mite domatia in a forest survey and links domatia presence to mite abundance.

## Key findings

- 80% of common woody species in the forest had mite domatia, the highest percentage reported to date.
- Plants with mite domatia had significantly more mites on their leaves compared to those without domatia.
- Mite abundance was consistently correlated with domatia presence and density across species.

## Abstract

Mite–plant defense mutualisms are among the most common defense mutualisms in the world—yet studies providing basic information on their prevalence in plant communities remain rare. Here, we systematically surveyed common woody plants in a North American deciduous forest for the presence of plant–mite mutualistic interactions. We scored 16 common woody species in a wooded natural area for the presence and number of mite domatia—small structures on the underside of plant leaves that are known to house mutualistic mites. We found that 80% of common woody species in the forest had mite domatia, the highest reported percentage of mite domatia in any survey conducted thus far. We paired our survey with a quantification of the number of mites found on each leaf and investigated the relationship between mite domatia and mite abundance within and across species. We found that plants with mite domatia had significantly more mites on their leaves than species that lacked mite domatia, and that plants with more domatia had more mites. Together, our study provides much needed systematic survey data on plant–mite mutualism prevalence in an important plant community and points to northern temperate forests as a promising system to study plant–mite mutualisms in high densities in the future.

Here, we characterize the incidence of a widespread yet understudied mutualism in a Northern Michigan deciduous forest: that between woody plants and fungivorous or predatory mites. We found that over 80% of the common woody species present in the habitat had mite domatia, and that mite abundance was consistently correlated with domatia presence and density across species. This work answers recent calls for more systematic surveys of plant–mite mutualisms in a wide range of environments, demonstrating the pervasiveness of domatia across woody deciduous forests in temperate environments.