Japanese Beetles

Strategies to Combat Japanese Beetles

Annual Roberts Lawn Treatment, provided by HOA (Prevention):

These beetles seem to affect different parts of the country in 2-3 year cycles.  Grubs in the soil will emerge in June or July as Japanese Beetles.  At that time (at first sight, usually June or July), Roberts will put down a soil treatment (Merit) to kill their eggs in the upcoming cycle to control future offspring. This lawn treatment is part of the 6 applications that we receive through HOA dues.  Merit in the ground kills these eggs to minimize grubs/beetles for the next year.  So, 2017 beetles were a factor of our 2016 treatment; 2018 beetles depend on our 2017 treatment, etc.


Additional Prevention & Intervention Strategies

(Must be paid by individual homeowners.)

Soil Drenches on landscaping (Imidacloprid)

In early Spring, apply around trees, bushes, especially: River Birches, Fineline Buckthorns, Linden trees, roses.  (Last year, nothing was safe.)  Can be expensive ($20/bottle for a small area).  Makes leaves taste bad, and poisons the beetles even if they eat it.

24-Hour Granular Dilox on lawns

Soaks into the soil in 24 hours and kills any grubs/beetles there for 48 hours. Very effective, but you have to be “on the money” in the timing on this one- ~ April or May.

Promethrin Spray–

Spray on leaves of trees, bushes, shrubs being affected.  Kills on contact;  active for 3-4 weeks, but most effective treatment effect is over the first 1-2 weeks, so multiple applications are necessary.  Beetles chew on leaves and die.

 What about Japanese Beetle Traps?-

Traps carry a strong pheromone that definitely will draw them to the bag.  Problem is, they will fly from 2 or 3 yards away to get to the bag, passing your lawn on the way.  They are very effective at drawing the beetles;  however, 2 problems can develop with the traps:  (1) they must be positioned far away from edible shrubs and trees;  (2) traps fill up quickly, and if not changed immediately prior to filling up, there are an exaggerated amount of beetles called out of hiding, looking for food, so they find the nearest shrubs and trees.

Roberts Nursery-

Robert’s Nursery will sell CR Residents the chemicals for 15% off and help us with the timing for the Resident-driven applications. Or, you may hire them as individual contractors to apply chemicals to your landscaping for an additional fee.  Safety of chemical treatments regarding pets, fruits and vegetable plants should be researched.


All that said, remember that Japanese beetles are flying insects… you can prevent, and you can treat;  but you cannot stop them from flying around from yard-to-yard, neighborhood-to-neighborhood.