INFESTATION LEVELS AND SEASONAL INCIDENCE OF THE MEADOW SPITTLEBUG (HOMOPTERA, CERCOPIDAE) ON MUSK THISTLE IN TENNESSEE

Infestation levels, seasonality, and distribution of the meadow spittl ebug, Philaenus spumarius (L.), on musk thistle, Carduus nutans L., we re monitored in eastern and middle Tennessee during a 2-yr study. Spit tle masses were found on thistle from early to mid-April until late Ju ne, and most (ca. 60 to 80%) were found on the leaf internodes along t he main stem. In eastern Tennessee, 50 to 90% of the plants were infes ted with spittle masses by early to mid-April; corresponding infestati ons were generally lower (0 to 10%) in middle Tennessee. Musk thistle development and populations of meadow spittlebug nymphs were well sync hronized, as suitable host plant material was available for nymphs dur ing mid-April to early June. Thus, musk thistle may be an important re servoir host for the meadow spittlebug in Tennessee. Spittlebug adults may subsequently move to grasses and economically important crops as musk thistle populations mature.