THE SUMMER WATERING GUIDE: 6 Steps to Watering Smarter
Read More
- Share
JAPANESE BEETLES: What you can do to be prepared, how you can spot their work and when and how to act
Categories: Garden Center, Resource | Posted: June 6, 2022
Maybe you’ve got the irrigation thing down. You know when to fertilize. You’ve even started deadheading your annuals, and you’re feeling pretty good about how full your containers are with more blooms than last year.
And then something unexplainable happens. Your lawn begins to die in streaky, irregular patches and the leaves on some of your plants look like Swiss cheese.
It can be incredibly frustrating, especially when you feel like you’ve done everything right. So here’s what to look for when it comes to Japanese Beetles (and grubs) and what to do next:
JAPANESE BEETLES
What are they?
Widely considered one of the most damaging and hard to control pests in the garden. Adults have oval-shaped metallic green bodies and bronze-colored wings. In midsummer when eggs hatch, young grubs emerge ready to feed. See #2 below for more information on grubs.
How to spot the problem
Adults feed on more than 300 species of plants, ranging from roses to poison ivy. They begin on the upper surface of foliage, chewing out tissue between the veins and giving the leaf a skeletonized appearance. You may also notice large, irregular holes in the leaves. Odor and location in direct sunlight seem to influence the beetle’s plant selection. From midsummer into late autumn, grubs feed on the roots of various plants and grasses, often destroying large patches of lawn.
How to control them
As with most pest infestations, early prevention is your best line of defense. Here are some things to keep in mind at any stage:
- Maintaining hardy, healthy plants is one of your best defenses against infestation.
- An application beginning in May/June is normally a very effective deterrent, as is Carbaryl and Eight. Several applications may be necessary during the active stage.
- Rose Pharm Insecticidal Soap, an organic solution is a contact control that requires multiple applications. Do not apply during the heat of the day to avoid potential damage to foliage.
- Try Milky Spore or Kill-a-Grub to limit the number of beetles you encounter next spring.
GRUBS
What are they?
Japanese beetles are often blamed for grub problems when the truth is, grubs can actually be the larvae of several different beetle varieties. Why all the fuss? The beetle larvae happen to feed on the roots of turf grass and other plants, sometimes wreaking major havoc on otherwise healthy lawns and plants.
How to spot the problem
Irregular dead spots caused by beetle larvae feeding on grass roots. Damage is worst in the fall. Dead turf pulls up easily, like a rug, revealing curved c-shaped larvae. Animals like gophers, moles and skunks will dig up lawn to feed on grubs.
How to control them
The key to controlling grub damage lies in understanding their life cycle. As with many gardening practices, timing can be everything.
- Grubs over-winter deep in the soil.
- Larvae move up toward the surface in spring as the weather and soil warm, eventually pupating into adult beetles. Because they are not feeding at this point, insecticides are rarely effective.
- Adult beetles generally begin to emerge in early summer and begin feeding on foliage and fruits. By mid-July, adults will lay eggs that hatch into small larvae. The larvae begin feeding in early August. This is the optimal time to apply insecticide.
- Young tiny grubs are most easily controlled.
- Always remember to water in your insecticide for optimal results and follow package label instructions.
- For best results, we recommend not using the same insecticide every year.
For more tips, advice or the same helpful products we use in our own yards and gardens, visit the friendly experts at Benken.
Leave a Reply