Potential for spread of plant pathogens by presence of red velvet mite (Balaustium sp.) in an Ohio landscape site

Abstract

We identified 12 different genera of fungi indicating a widespread diversity on the body surface of Balaustium sp. in each of its mobile stages. Penicillium sp., Aspergillus sp., Cladosporium sp. and Stigmella sp. were the most prevalent. Less frequent fungi were Alternaria sp., Beauveria sp., Fusarium sp., Mucor sp., Paecilomyces sp., Scopulariopsis sp., Trichoderma sp. and Verticillium sp. All of these fungi are heavy spore (conidia)‐producing soil saprobes (all are saprobes except Trichoderma sp., which is mycoparasitic), featuring high rates of growth (K r), and were presumably acquired by the mites from the soil and leaf litter where they live. The absence of any fungi internally within the mite body contents for any stage implies that these mites are not fungivores (they are predatory, mostly on scale insects) and there is no infection, so it is unlikely that these fungi serve as natural regulators of the Balaustium population at this Springfield, Ohio site. Most of these fungi are classified as pathogenic to plants (leaves), e.g. Stigmella sp., Alternaria sp. and Verticillium sp., suggesting that these mites could act as a mode of dispersal of plant disease by carrying these fungi through the landscape. The relationship between Balaustium sp. and plants is problematic because of their large numbers, heightened activity, and excessive contact with plants in search of prey. This is mainly a point of public awareness, showing that Balaustium sp. mites can carry plant pathogens.