Monday, June 20, 2022

Those Hungry Beetles


Horticulture Hotline 06/20/22

By Bill Lamson-Scribner


The windy, dry spring has been absolutely crazy! Now, record-breaking temperatures as well! I have been so busy I missed that May was National Skin Cancer Month. Working in a field that is mostly outside in the sun, I have many friends dealing with sun cancer.


Dermatologist have come a long way in getting the word out about sun cancer. When I used to swim competitively for hours in the pool (morning practice, then noon – two, then evening practice), pick tomatoes on John’s Island for a quarter a bucket, work landscaping, and work construction, the only sun protection I used was when I swam, I used that white zinc oxide on my nose (and a Speedo! Many of you could do without that visual this morning!). Some people even used some coconut smelling Hawaiian Tropic oil to attract the sun! Now, it seems that sunscreen is much more popular. Shirts and gloves that protect you from the sun. Wide brim hats and face coverings are more popular. Protect yourself!


Japanese Beetles have emerged from the ground and are munching down on our ornamental plants like there is no tomorrow, leaving behind lacelike foliage everywhere they dine. The warm weather has also caused the cockroach and rats to move inside for a little air conditioning (can you blame them?) and the calls are rolling in about chinch bugs and fleas.


Japanese Beetles come out of the ground here around the beginning of June (as you probably noticed) as beetles. In parts of the country, they are the number one damaging insect to ornamentals, and they seem to be gaining a stronghold in the Lowcountry. In the 1990’s, I can remember talking to friends in Charlotte, whose plants were getting devastated by this ferocious eater, and they would say how lucky we were not to have them down here in the Lowcountry. Roses and Crepe Myrtles are some of their favorite plants.


Once the Japanese Beetles come out of the ground, they eat and mate. A female returns to the ground to deposit between 40 and 60 eggs (you can see how the populations can grow rapidly). The female beetle must burrow in the ground to lay eggs and the eggs need moisture to survive. A well-irrigated landscape is a lot easier for the beetle to dig in than a dry, hard, area. The adult beetle dies off and the eggs turn into grubs over the summer. By mid to late August, the grub is full-grown and overwinters in the soil. In late May to early June, the adult (beetle) emerges again and the life cycle starts over.  


The grubs from this beetle damage grass and other plants by eating the roots. Using a product like Grubz Out or Sevin in late August or early September (if your grub populations warrant treating) or in April will help your turf; however, do not fool yourself into thinking all your beetle problems will be solved.  The adult beetle can fly for miles to chow on your precious ornamentals! Milky Spore is an organic option that seems to do a good job now that our grub population is high enough for the spores to have a steady food source.


Using a ground drench systemic insecticide in the early spring like Dominion will help protect your plants, and you might get lucky and kill a few grubs while you are drenching! Once the beetles are eating your plants, use a good contact insecticide to kill them. Cyonara and EcoVia EC (National Organics Program Compliant) are two of the many products that will help control these beetles. Since contact insecticides have limited residual activity, plan to reapply the product according to the label.


Traps for Japanese Beetles are a little controversial. The attractants they use (one is a virgin female beetle scent) can lure more beetles to an area than the trap can trap! Many ornamentals on the way to the trap and near the trap can suffer extensive damage. For this reason, place the traps away from the plants you are trying to protect.


Roaches, fleas, mice, and chinch bugs are becoming uninvited guest in many homes and yards. Are you protected from these unwelcome guests?