Incidence of Arthropods Infested with Conidia of the Dogwood Anthracnose Fungus, Discula destructiva Redlin, on Flowering Dogwoods in the Natural Environment

Arthropods were collected from flowering dogwoods infected with Discula destructiva Redlin, causal agent of dogwood anthracnose, to evaluate their ability to transport viable conidia. During 1994, 7.2% of all arthropods collected (n = 375) from diseased trees at three sites in the Great Smoky Mountains National Park were carrying viable conidia of D. destructiva. Most [92.6% (25/27)] of the conidia-infested arthropods were collected during June when sporulation and spread of dogwood anthracnose were increasing. From July through September, the expansion of disease severity and incidence of sporulation diminished and the frequency of conidia-infested arthropods decreased. Several species of arthropods with viable conidia of D. destructiva were collected lending support to the hypothesis that insects and other arthropods may play a role in the spread of dogwood anthracnose.