Suppression of citrus rust mite populations with application of fragmented mycelia of Hirsutella thompsonii

Large quantities of mycelia of Hirsutella thompsonii, a fungal pathogen of the citrus rust mite, Phyllocoptruta oleivora, were produced by use of a submerged culture technique. The mycelia were then fragmented and applied as a foliar spray to orange trees infested with high populations of the citrus rust mite. The mycelia began to sporulate on the foliage about 48 hr after application. The mean number of mites per leaf decreased and the rate of mite infection increased at 1 week post-treatment. Mite populations remained at low levels for 10–14 weeks.