The Rose chafer (Macrodactylus subspinosus) is a hungry garden pest. This beetle begins its life as larvae under the soil.
Adult Rose Chafers are medium-sized, greenish brown beetles which tend to arrive in great numbers and spend most of their time eating your garden and mating.
Rose beetles are especially abundant in areas with sandy soil because the adult beetles prefer to lay eggs in sandy soil.
In this article, we describe Rose Chafers and their activities along with sharing advice on protecting your garden and keeping the chafer beetle under control. Read on to learn more.
What Do Rose Chafers Do?
The rose chafer larvae grubs live in the soil and eat a wide variety of roots. However, they do not damage lawn grass.
The chafer grubs overwinter below the frost line in the soil and emerge in the springtime as fully formed adult beetles.
Adult Rose chafer beetles cause a great deal of damage to a wide variety of plants including:
- Shrubs
- Trees
- Fruits
- Flower blossoms
- Landscape plants
- Garden plants
In addition to causing damage to many different types of plants, Chafer beetles can also simply be annoying to people.
The beetles fly about a great deal during their busy time of year, and they can easily land on your clothes or in your hair.
The Chafer beetle does not bite, but it is creepy because their legs are so long, spindly and spiny. They become entangled very easily and can cause a great deal of anxiety.
Another thing to watch out for is that Chafer bugs have a tendency to climb up your pants legs on the inside. This also causes great alarm and may lead to impromptu improvisational dance.
What Do Rose Chafer Beetles Eat?
There is very little this rose beetle does not eat. They eat flowers, most especially roses and peonies. They also eat the leaves of a wide variety of plants. They are especially damaging to:
- Strawberries
- Apple Trees
- Cherry Trees
- Birch Trees
- Raspberries
- Grapes
- Peonies
- Roses
These are just a few of their favorite foods, but they will happily go after any available plant or fruit. Chafer bugs cause a great deal of damage by leaving large numbers of ragged holes in blossoms, fruit, and leaves.
The beetles skeletonize the top layer of leaves on plants by eating away all of the soft tissue and leaving nothing but the large, tough veins.
What Eats Rose Chafers?
Unfortunately, nothing eats Rose Chafers. They are poisonous and eating them can kill birds and small animals. If you have pets or chickens, be sure they do not play with or consume Rose Chafers.
On the bright side, parasitic nematodes do attack and consume the chafer larvae. An application of beneficial nematodes (Amazon) to your garden soil can be very helpful in reducing your beetle larvae and subsequent beetle population.
Are Rose Chafers Beneficial?
Although the Rose Chafer beetle is nothing but pests and does cause a great deal of damage the larvae actually also have some benefit.
Rose chafer larvae are known as important detritivores. In other words, they eat detritus such as dead and decaying leaves, branches and other organic, compostable material.
For this reason, the larvae can be very helpful to your compost heap.
Some very dedicated organic gardeners do make use of the chafer larvae in this way.
However, when you allow the larvae of rose chafers to feast on your compost pile, you are likely to end up with a great deal of beetle monitoring and control duties.
What Is the Lifecycle of the Rose Chafer Beetle?
Chafer white grubs mature and emerge from the ground as adult beetles in late May or early in June. They begin feeding on plants immediately and continue voraciously for about a month.
At this time, female Rose Chafers lay eggs in the soil and then die.
In about three weeks, the beetle eggs hatch. The tiny larvae feed right away eating the roots of grasses and weeds. The chafer larvae overwinter underground all winter just below the frost line.
When the weather begins to warm up, the beetle grubs transform into pupae and then metamorphose, become beetles and emerge from the soil to begin the whole cycle again.
This cycle might lead you to believe that you really only need to worry about Rose Chafer beetles for a month out of the year, and this is actually true.
Unfortunately, after the Rose Chafer beetles finish their cycle you may need to start dealing with Japanese beetles. They are quite similar to Chafer beetles and can be dealt with in many of the same ways.
Rose Chafer Beetle Control [How To]?
Keeping the hungry and prolific chafer beetles away from your plants can be a big challenge early in the growing season.
You must pay close attention and act quickly and decisively to prevent their destruction.
Pick & Drown
When the weather begins to warm up, begin checking for the presence of Rose Chafers. Make sure you have a bucket of soapy water handy.
When you catch them early and in small numbers, you may be able to deal with them by simply picking them off your plants and dropping them into a bucket of soapy water.
This is a daily task you need to do because waves of adult chafers will continue to mature and emerge from your soil and onto your plants.
Additionally Rose Chafers may fly in from neighboring gardens to feast on yours.
Vacuum:
For a larger infestation, try using a shop vac to vacuum the chafer beetles up. Be sure to install a vacuum cleaner bag so you can easily remove your catch.
Seal up the bag in a plastic bag and dispose of it in the trash.
Block Beetle Access:
Another way to deal with Rose Chafers is by preventing them access to your plants. You can do this by installing a floating row cover or covering your plants with cheesecloth.
Do this as soon as you see Rose Chafers on the plants. Take the row covers down after about a month when these beetle pests have stopped feeding.
Controlling Rose Chafers Using Insecticides:
With a very heavy Rose Chafer infestation insecticides may be the only control option. Look for products including one or some of these ingredients:
- Imidacloprid
- Permethrin
- Cyfluthrin
- Bifenthrin
- Carbaryl
If you have a very heavy beetle infestation, you may need to treat your plant several times.
Make certain the product you choose is specifically approved for the type of crop you are treating. Pay close attention to the number of days between your last application of the pesticide and your harvest date.
How Do You Recognize Rose Chafers?
The larvae of Rose Chafers are typical white grubs with plump bodies bent into the shape of the letter “C”. Their brown heads, white bodies and their legs are quite conspicuous.
A fully grown grub is about ¾” of an inch long. You will seldom see these chafer larvae as they are naturally buried in the soil.
Mature Rose chafer beetles are medium-sized. They are ½” inch long or smaller. These are slim beetles and tan and/or greenish in color.
Their legs are orange or reddish brown, long, spindly and quite spiny. These beetles have short antennae.
It’s easy to mistake Rose Chafers for wasps when they fly.
They are also sometimes mistaken for Japanese beetles or False Japanese beetles, which are similar but are active at different times of the year.
How Are Rose Chafers Different from Japanese Beetles?
Japanese beetles and False Japanese beetles are quite a bit like each other and somewhat similar to Rose Chafer beetles.
You can tell Rose Chafers apart from them because Rose Chafers are somewhat smaller, are not bright metallic green, and they don’t have hair patches on their abdomens.
Many of the same beetle control techniques can be used for all three types of garden pests.
Remember these beetles are active at different times during the growing season.