Gardeners at FCG have just spotted the first Japanese beetles of the season. So far, just a few have been found, but diligence is the name of the pest control game.
We’d like to share with you some information about Japanese beetles featured in the Denver Post on July 17th:
We are at the height of adult Japanese beetle activity, lasting about 4-6 weeks. The adults are feeding and mating, preparing to lay eggs. The expert advice might sound counterintuitive: Stop trapping them. And hold back on watering lawns in the summer heat as female beetles will be seeking a moist spot to lay eggs.
The Japanese beetle traps attract more beetles from neighboring yards than they trap. Better to go out in the cool morning and knock the sluggish beetles into a container of soapy water, where they quickly drown. Shaking beetles off plants in the morning and evening will reduce feeding, which decreases the volatile odors and limits future attacks.
You can make your lawn more resistant to the grubs (young beetle larva) by raising your mower blades. The grass grows deeper roots, so it can better survive the root-chewing damage of the grubs. Also, don’t overwater; let your lawn go close to dormant so beetles skip your yard and will fly to over-irrigated yards to lay eggs. Egg-laying should be finished by August.
The article ended by saying there are still too many things we don’t understand about Japanese beetles, so we gardeners need to be on the lookout for the latest information. Please visit the CSU Extension website for more information.