Effects of the Insecticide Imidacloprid on Fungal Mycelial Growth

Abstract

Eastern hemlock (Tsuga canadensis), a foundation species, is a widespread dominant species in the eastern USA and is associated with a unique suite of habitat characteristics, including dense shade, acidic soils, deep litter layer and cool moist conditions. Tsuga canadensis is being attacked by the Hemlock woolly adelgid, which is an aphid-like insect native to Asia that was introduced into the eastern USA in the 1950s. Eastern hemlock has no apparent resistance to Hemlock woolly adelgid, and Hemlock woolly adelgid introduction generally leads to mortality of infested trees within 5–15 years. A variety of insecticides are capable of controlling hemlock woolly adelgid. The use of a systemic insecticide, imidacloprid, has gained widespread acceptance and use in the plant care industry. There has been a lot of research done on the effectiveness of this solution and the effects of imidacloprid on the overall health of the tree, but there has been very little research into the effects of these treatments on fungi that occupy the soil around the trees. Fungi play an important role in the ecosystem, whether they are being saprotrophic and recycling nutrients, or they are making symbiotic associations with the surrounding flora. As fungal species are lost from a community, there are functional consequences for the productivity of plant life. This research hopes to find out if imidacloprid has an effect on the growth of fungal mycelia.