Remember the days before the Japanese beetle invasion?

I remember the good old days, pre-beetle. Rose buds matured into beautiful flowers. Dahlias, too, bloomed without having petals chewed off. And a jar of soapy water wasn’t a permanent fixture on my patio.

My nostalgia is for a time, about seven years ago or so, before Japanese beetles entered my garden and my life.

These garden invaders with iridescent backs and legs that stick out like swords when you try to grab them attack a wide range of plants, particularly roses, raspberries, grapes, dahlias and a variety of trees including birch, linden and Norway and Japanese maples. In large numbers they can defoliate and weaken trees over time, and they can lay waste to ornamental plants. The adults do plenty of damage, but the beetle larvae — fat grubs that kill turfgrass by munching through the roots — may be even more damaging.

And this year, they seem particularly bad. The population ebbs and flows, but normally they are gone by this time after arriving in late June, but so far they show no signs of retreat.

Unfortunately, there is no great solution to managing these pests.

My go-to method has always been the simplest and least invasive — a jar of soapy water into which the little buggers are flicked or forcefully thrown (they will fly away given the opportunity). In the past, a daily pass would keep them in check, but in the past few weeks new beetles have appeared on just-checked plants within minutes. I’ve heard of large public gardens using a handheld battery-operated vacuum to suck them up.

Applying a spray containing BT, aka Bacillus thuringiensis galleriae, can help and is safe for beneficial insects so long as it is sprayed on plants and allowed to dry when pollinators are not present. Non-selective chemical insecticides will also work, but they will kill all insects, including beneficial ones, so they are not appropriate in most cases.

One method that is not recommended is using Japanese beetle traps. The traps work, but they work so well that they have been shown to attract beetles from far and wide, and as soon as the traps are full they find something nearby to feed on.

Milky spore, which is the common name for a particular bacteria that kills the grubs, can help control the population, but it’s no miracle cure. Not only must it be applied consistently for two or three years, it also only works when applied on a large scale, such as an entire neighborhood.

Parasitic nematodes are not widely available for homeowners in the United States, but they are common in other areas and can be helpful in controlling pests. Some varieties of these microscopic worms feed on Japanese beetle grubs and can be used to reduce the population in the ground.

Unfortunately, these flying menaces travel up to five miles, so local control in your yard won’t solve the problem. Like many garden problems, there’s not an easy solution, but a combination of several methods should help.

Just remember the first rule of Japanese beetle season — don’t get your cocktail glass mixed up with the beetle jar.