It is easy to spot Japanese beetles because of their distinct appearance. When they are adults, they develop a metallic green body and wing covers that are copper brown. On their side, there is a row of small white hair. At this stage, the length is usually ½ inch. Meanwhile, when they are in the larval stage, their average length is ¾ inch
Japanese Beetle’s Habitat
From its name, it is obvious that the pest is native to Japan, although, in the country, it is not much of a pest. In the United States, it came in 1916, and since then, it was a major cause of infestation in different crops. As opportunistic feeders, they thrive in more than 300 species of host plants. They are more common during days that are sunny and warm. This is why their favorites are the plants facing direct sunlight. They can damage almost every part of the plant, such as fruits, flowers, and leaves. You will see them feeding in groups, usually starting from the top part of the plant going all the way down. Japanese beetles start spreading damage in June and usually has a lifecycle of only 40 days.
Identifying Japanese Beetle’s Damage
Japanese beetles are present in more than 300 species of plants. Some of their primary hosts include maples, asparagus, soybean, peach, plum, roses, raspberry, blackberry, lime, elm, corn, and grapes. There are also secondary hosts, which include American walnut, birch, buckeyes, chestnut, and American mountain ash.
Watch out for the following symptoms, which will be indicative of the presence of Japanese beetles:
- The appearance of multiple holes on the top of the lead is one of the most common symptoms you need to watch out for. This is where they usually start feeding. They will attract other beetles and once they are already in a colony, they become more destructive. In the end, only the skeleton of the plant will remain.
- Turf damage is also a common symptom. This is especially true in the case of turf grass in the garden and even on the golf course. The grubs or the larvae are the ones responsible for this damage.
- Aside from the holes, they will also make the leaves turn green. This is because the infestation deprives the plant of the nutrients that are necessary for its growth. When the leaves do not receive these, they end up turning dark and they will die.
- Damage of the pest will also be evident on the roots. In turn, this lessens the ability of the plant to absorb water. With this, there will be brown and dry patches of grass.
Results of Infestation
It is one of the most destructive pests in the United States and in other countries where they are present. They are most destructive when they reach maturity, but even during the larval stage, they will cause significant damage to their host plants. The annihilation of the leaves is one of the most common results of their infestation. This affects the nutrients that plant gets. The plant will also end up being skeletonized. The aggressive feeding patterns of the bugs will take out the leaves and plant tissues, leaving only the bare skeleton of their host.
How to Get Rid of Japanese Beetles
Natural and Organic Solutions
To kill Japanese beetles and to make sure that they will not cause significant damages, the following are some of the measures you might want to consider:
- One of the first solutions is the physical removal of the pest from the host plants. Knowing the physical characteristics of the Japanese beetles will make it easy to spot them. Shake the plant early in the morning. This is a time wherein the beetles are sluggish. To kill the beetles, dunk them in a bucket of soapy water. This solution, however, will only work best if the population is still small.
- Using row covers is an easy solution to get rid of these pesky pests. The floating row cover will protect the surface of the plant, but this is only for plants that do not need pollination. Because of the cover, they will not attract bees.
- There are also traps that you can buy from stores or make on your own. There are baits that emit a scent similar to virgin female beetles. There is also a bait with a sweet smell that will be attractive to Japanese beetles.
- Another simple trap that many people find surprising is a fruit cocktail. Ferment a can of fruit cocktail under the heat of the sun. Leave it sitting for one to two weeks. Place the fruits on the top of a brick in a pail with a light color. Position it about 25 feet from the host plant. Its sweetness is effective in attracting Japanese beetles.
- In lieu of the traditional pesticides that can result in harmful effects, you can consider natural alternatives. With this, one that should be on the top of your list is neem oil. It has chemicals that adults pass to the eggs. With this, the larvae will die even before they fully mature.
- Encouraging natural predators in the garden will also be a big help. They will get rid of the beetles from the eggs to their adult form. Some of the insects that often feast on beetles include praying mantis and robber flies.
For many commercial growers and large plantations, they resort to the use of chemicals. However, they may pose more harm than good, especially with incorrect application. Using pesticides with toxic chemicals will harm not only Japanese beetles, but other insects, including those that do not pose any threat in the garden. Some of the most common active ingredients in these chemicals include esfenvalerate, deltamethrin, and lambda cyhalothrin.
How to Prevent Japanese Beetles
Among others, one of the best preventive measures is the wise choice of plants to have in the garden or even for commercial plantations. You should choose resistant varieties. Some of the best plants include burning bush, magnolia, and red maple. Another strategy that will work best is companion planting. Planting garlic is one thing that will help.