The ecology and network structure of mushroom-insect interactions from two forest regions in Southern Ontario

Abstract

Mushrooms and insects are both integral components of ecosystems worldwide. Interactions between these two groups of organisms are particularly interesting to study due to the transient nature of mushroom fruiting bodies, which form for a short period of time when environmental conditions are optimal to allow the fungus to distribute its spores. Despite this unpredictability in where and when mushrooms will grow, a variety of insect species use mushrooms as a food source and a substrate on which to lay their eggs. Interactions between these two groups of organisms have been documented extensively in Europe. However, little is known about the diversity of insects that associate with mushrooms in Canada. In this study, 1,017 mushrooms were collected from forests in Hamilton and the Tillsonburg, Ontario regions between fall 2018 and fall 2019. Mushrooms and their associated insects were identified through DNA barcoding using sequences of the nuclear ITS region and the mitochondrial CO1 gene for the mushrooms and insects, respectively. In total, more than 100 insect species from at least 35 families and five orders were identified from the approximately 200 mushroom species collected. While some insect species displayed evidence of specificity in their choice of mushroom host, the larger network of associations was moderately generalized and many insect species inhabited mushrooms from multiple families and orders. This study highlights the incredible diversity of organisms that rely on mushrooms for survival and contributes to our overall understanding of mushroom-insect associations in this region of Southern Ontario.