Preplant media incorporation of Talstar 0.2 G (bifenthrin) at 10 ppm (parts per million) or Fireban 1.5 G (tefluthrin) at 15 ppm, based on dry weight of the medium, provided complete control of Japanese beetle (Popillia japonica Newman), oriental beetle [Exomala orientalis (Waterhouse)], and European chafer [Rhizotrogus majalis (Razoumowsky)] in container nursery plants for two growing seasons. Talstar 0.67 F drenched immediately after planting also prevented establishment of these species in containers for two growing seasons. Marathon 1 G (imidacloprid) preplant media incorporated at 6–17.8 g (a.i.)/m3, provided incomplete control, while Marathon 60 W was completely effective when drenched in mid-summer prior to inoculating the pots with eggs. Other granular products mixed into potting media, including 10 ppm of fipronil or Mach 2, or 150 g (a.i.)/m3 of Lorsban or SuSCon Green, provided good control for one season. Several treatments prevented establishment of Japanese but not oriental beetle grubs. Curative drenches were generally ineffective. Registered treatments providing two years of control (Talstar at 10–25 ppm) can be used by growers to prevent white grub larval establishment in containers. Their usage should allow shipment of treated plants throughout the United States and Canada.
We thank Steven R. Alm, University of Rhode Island, for providing Japanese beetle adults and oriental beetle larvae; Bruce Morse, superintendent, Norwich Golf Course, for oriental beetles; Imperial Nurseries for pots, potting media, and a site for conducting the Connecticut study; Latha Guddera provided technical assistance. Sarah J. Hilty provided capable assistance with all portions of the Ohio studies. Cottage Gardens provided potting media, plants and containers for this work. Partial funding was provided by The Robert Baker Companies and the Ohio Research Endowment and The Horticulture Research Institute, 1250 I St., NW, Suite 500, Washington, DC 20005.
3Connecticut Agricultural Experiment Station, Valley Laboratory, Windsor, CT 06095.