The appearance of pests and insects that damage plants is always a problem that worries garden owners. Many species not only reduce productivity but even destroy the whole farm.
So what about the beetles on grapes? Are grapevine beetles harmful?
Scroll down and get the answer.
What Are Grapevine Beetles?
The Grapevine beetle (Pelidnota punctata), also known as the Spotted Pelidnota or Spotted June beetle, is an insect distributed mainly in central and eastern North America.
It belongs to the family Scarabaeidae – the same family of several other common insects as Rhinoceros beetles, scarab beetles, Japanese beetles, dung beetles, etc.
This type looks quite similar to the June beetle but has spots on the body.
Its body structure consists of three parts: head, thorax, and abdomen. The two club-shaped antennas in front of the head are called lamellae.
They can curl these antennas or deploy them to sense obstacles around them.
Grape beetles can be yellowish orange or dark brown and often have a pale yellow or reddish brown pattern with four black spots evenly located on both sides of the body.
Their leg color is usually black or brown, depending on where they live.
Those living in the North often have dark legs, while those in the South do not. Their spots can also vary depending on the distribution region; beetles in the southern area will have fewer spots.
The cycle of beetles goes through 4 stages: Egg – Larva – Pupa – Adult beetle.
Are Grapevine Beetles Harmful?
No. This beetle is very common in vineyards, hence its name. Their main food source is the plant’s leaves, tree stems, roots, flowers, and fruits, but they are not generally harmful or cause major damage.
The damage they cause is nothing compared to the major pest of grape farms, such as fungi, the Lobesia botrana moth, the Japanese beetle (Popillia japonica), black rot, gray mold disease, etc.
Their eggs and larvae also only hatch and develop on the base of dead vines or rotten wood. This should not have a major effect on the growth and health of healthy plants.
Adult bugs love to eat, and they can sometimes cause large holes in the foliage. This will affect the plant’s photosynthesis and reduce the fruit’s quality.
After all, its damage to plants is relatively low. It does not affect a vast scale, so a few of these beetles in the garden is not a cause for alarm for gardeners.
However, increasing their density too quickly can also cause severe consequences.
How To Get Rid Of Grapevine Beetles Naturally?
Although the situation where beetles on grapevines become a serious problem is rare, it is not impossible.
Gardeners should still prepare a few extermination and prevention measures to protect their farms best. Here are suggestions to get rid of beetles:
The first is catching them directly by hand or using a racket. This is a method that many farmers and gardeners apply because they are easy, does not require techniques, and does not cost money.
It also has the advantage of not causing any harm to the environment.
If it’s early in the season and you only see a few bugs, you can pick them up right from your tree. You can also use a racket to catch insects to catch them when they land on a tree.
The type of racket you should use is a soft net.
Then drop them in soapy water to kill them. Or in the morning, when these leaf eaters land on the grapevine leaves and trees, shake them vigorously to make them fall to the ground and destroy them.
After all, this method still has a few downsides. These insects are mainly nocturnal, so finding them won’t be easy.
So the best period of time to do it is early morning or late afternoon. You can shine a light to catch it, but it is very laborious and ineffective.
Picking by hand can make you feel overwhelmed and want to give up after catching a few. Using Diatomaceous earth would be a good choice.
Diatomaceous earth (DE) is a natural powder produced by crushing the carcasses of hard-shelled organisms.
In the cells of these diatomaceous earths, silica content is high and very safe for human consumption. They are present all over the world.
It is usually in the form of a white powder. It is also used in water purification, food production, leather products, and farming to remove free radicals, parasites, insects, viruses, and other harmful organisms by binding and drying them.
According to the Insecticide Act in the US, killing fungi and insects with DE is safe for household use. Sprinkle it directly on the leaf parts that have bugs.
The seeds will get into the shell, causing them to lose water and then cut their body in half. Eventually, the insect will kill itself.
DE is also useful in food preservation, as a natural home cleaner and deodorizer, and to help treat livestock with parasites.
Nematodes are the name of an invertebrate animal belonging to the phylum Nematodes. Nematodes are very small and cannot be seen with the naked eye, so people need microscopes to see them.
Nematodes have many species and can live in many different types of environments.
They also can quickly adapt to the change of habitat because when the plant is infected with root nematodes, it will be difficult to handle.
In agriculture, nematodes include 2 main types: beneficial nematodes and harmful nematodes (plant parasites):
Beneficial nematodes are species capable of parasitizing harmful insects such as grapevine beetles, corn silkworms, crickets, locusts, earthworms, mosquitoes, weevils, omnivores, leaf aphids, etc.
By injecting their symbiotic bacteria into the host’s body, the nematodes can help destroy the host plants quickly.
In addition, some species in this group also inhibit microorganisms and aid in decomposition.
Insecticidal Soap Spray
Dishwashing liquid is a benign and indispensable detergent in every household. In addition to cleaning, dishwashing liquid or soap is also an effective insecticidal method, which is also popular with farmers.
Check the garden regularly, observing the foliage below ground, foliage above, trunks, and stumps.
When detecting the presence of beetle eggs, mix a solution of dishwashing liquid in the ratio of 1 ml dishwashing liquid to 180ml water.
Then spray on plants that are attacked by them or spray directly on the egg and leaf surface. You should apply this method in the period before the bloom time.
When pouring dishwashing liquid on the eggs, they will die immediately and can no longer grow.
For adults, spraying dishwashing liquid directly on the body will also help kill these predators. It will make them unable to breathe, dehydrated, and slowly die.
Remember that with big ones, you have to spray directly on them to have an effect.
Those who fear the concentrated soap solution could harm the plants can dilute it more, but liquid soap will only stun the insects. You still need to pick them up by hand.
Milky Spores are naturally occurring bacteria capable of infecting larvae that ingest and kill them. The advantage of this method is that it is harmless to people, animals, and plants.
You can use it for the garden without fear of affecting the yield.
They can also last for a very long time, about 2 – 10 years, in the soil, so they have a long-lasting effect. However, this type of bacteria also takes 2-3 years to be effective.
How To Prevent Grape Leaf Beetles?
Clean agriculture is the trend farmers aim for, so insecticide-free pest control measures and organic materials are always a top priority. Refer to some care guides to prevent insect invasion below.
- Use a mint solution: Mint can also repel bugs. Just dissolve 10 drops of peppermint essential oil with 500ml of clean water, and you immediately have an effective bug-killer spray.
- Use garlic juice: To make garlic juice, you must crush a few cloves, extract the water and mix it in 500m of clean water. Spray this solution on petioles, young shoots, and leaves to repel leaf eaters.
- Use organic pesticides: there are many types, but you should prioritize using drugs like pyrethrin, alcohol, and rotenone because they are safer than chemical pesticides.
- Improve the growth environment of plants, clear bushes, clear drains to create flows to kill larvae, and improve irrigation systems.
- We use natural enemies, bacteria, pathogenic fungi, insectivorous insects, vertebrates, etc.
Do Grapevine Beetles Bite?
No, don’t worry about that. Unlike many other beetles, the ones on grapevines only target plants (roots, leaves, tree stumps) and fruit of grapevines. They don’t bite people and animals.
Are Grape Beetles Toxic To Humans?
No. They are a hazard to the vine but are essentially non-toxic to humans because they do not contain or emit any toxins. You can rest assured when, unfortunately, in direct contact with them.
What Is The Life Cycle Of Grapevine Beetles?
Two years. Yes, you are not mistaken; their life cycle, from egg stage to adult beetle, can last two years. The number may surprise many because most insects that damage plants usually do not last long.
After reading this far, surely readers have found the most suitable answer: are grapevine beetles harmful? The damage is on a small scale, so they are not a serious problem.
You can easily remove and prevent them with my suggestions above.