Japanese Beetles feed on grass roots until late September when cool soil temperatures cause larvae to move downward into the soil to overwinter. Development is completed the following spring. One generation occurs each year. It is important to start treatment prior to egg hatch. For optimum control when apply Merit 75 WP, irrigation or rainfall needs to occur within 24 hours of the application to move the product through the thatch layer and into the soil. Please refer to the product label for complete application instructions. You can contact your local cooperative extension office to see when egg hatch normally occurs in your region.
Please contact your local cooperative extension office to determine the correct timing of the application as this will vary greatly from region to region. Per the product label for Merit 75 WP: Application to trees already heavily infested may not prevent the eventual loss of the trees due to existing pest damage and tree stress. Since it can take up to 8 weeks to translocate it can take time to kill the larvae and works best applied before an infestation.
Yes, you can use Merit 75 WP on trees that aren't infected with anything; however, be aware that there is a limit on how much product you can use per year. As a low cost alternative we recommend Dominion 2L which has the same active ingredient as Merit and treats the same insects. One bottle of Dominion 2L contains enough product for about 137 inches of tree trunk diameter at the highest concentration, where one 2 oz jar of Merit 75 WP contains enough product for about 30 cumulative inches of tree trunk diameter (at the highest concentration for systemic control).
Merit 75 WP is not labeled for use on cherry trees or other edible plants. ImidaPro 4SC is labeled for use for aphids on sweet and tart cherries. The best way to prevent fruit flies is to pick ripe fruit and pick up fallen fruits as soon as possible. You also can use Yellow Sticky Traps around areas where you frequently get high numbers of flying insects.