By Tim Gibb, Department of Entomology, Purdue
and Zac Reicher, Department of Agronomy, Purdue University
The first Japanese beetles of the year were observed in central Indiana on Tuesday June 17th. We expect them to arrive in full force within the next 2-3 weeks and begin feeding on their favorite plants. Plants particularly at risk include those that have been recently transplanted or those that are stressed for one reason or another. Favorites for Japanese beetle include linden, crab apple, plum, and other fruit trees, rose bushes, grapes, and several garden variety vegetables. Physical (netting or picking off the beetles each day) or chemical controls (Sevin, Orthene, Malathion or any of several Pyrethroids) may be required to protect plants from Japanese beetle defoliation.
After adult beetles mate they will lay eggs in turfgrass areas. The resulting larvae, called white grubs, can also be very devastating as they prune the roots off of the grass. Insecticides available for grub control only work AFTER the grubs have hatched - usually the end of July or the first part of August. Two very effective grub control products include imidacloprid (Merit) and halofenozide (Mach 2). Both products are very long-lasting but must be applied as preventative treatments. They are most effective if applied from late June through July. As with all insecticides, it is critical to follow the label directions exactly when making applications. For grub control products it is recommended that 1/2 inch of irrigation be applied immediately after treatment. In cases where irrigation is not possible, timing the application to just before a significant rainfall event is recommended.
See the following link for more information:
Click on image to enlarge.
The information given herein is supplied with the understanding that no discrimination is intended and no endorsement by the Purdue University Cooperative Extension Service is implied. Any person using products listed assumes full responsibility for their use in accordance with current direction of the manufacturer. Purdue University is an equal opportunity/equal access institution.
Information listed is valid only for the state of Indiana.