Diamondback Moth Larvae Control: How to Identify, Prevent and Get Rid of Diamondback Moth Larvae

Diamondback moths are some of the most common pests you can find in many home gardens. They are most destructive during their larval stage, or the point after hatching from eggs and before transitioning into full adulthood. With this, it is important that you are aware of how to get rid of diamondback moth larvae, which will provide you with the ability to successfully execute a number of preventive and control measures.

In the larval stage, diamondback moths have light green color and the length usually ranges from ¼ to 1/3 inch. When they mature, on the other hand, they turn to gray and has an average length of half an inch. Lastly, when they are in the form of eggs, they are yellowish white, round, and appear in clusters.

Light Green Diamondback Moth

A Light Green Diamondback Moth

Diamondback Moth Larva’s Habitat

The diamondback moth larva can be often seen feeding on the outer layers of the plant or the older leaves. They are also common in the flower buds and stalks. It takes about 14 days for the larvae to mature, which is also the point at which it is at its most destructive. They can also hang on the host plant, especially if the plant is disturbed. At this point, you will notice a thin and silky thread.

Identifying Diamondback Moth Larva’s Damage

Plants Affected

This pest is present exclusively in the Cruciferae family. Some of the most popular host plants include cabbage, broccoli, bean sprout, cauliflower, kale, radish, watercress, turnip, and mustard, among others.


The following are some of the most common symptoms that will be indicative of the presence of diamondback moth larvae in the garden:

  • Plant stunting is one of the occurrences that will give you a sign that these pests are present. This leads to the poor development of the plant, which is basically because of the inability to have the nutrients that are necessary for its survival.
  • The appearance of holes in the leaves will also show that diamondback moth larvae are present in the garden. They will chew on the surface of the leaves, like a typical garden worm. For leafy vegetables, it damages the physical appearance. In most situations, this prevents the plant from having the optimal nutrition that it requires for a healthy growth.
  • Pay attention as well to the head of the cruciferous vegetable. Diamondback moth larvae can eat the head, which can lead to making it unattractive and worse, unmarketable.
  • Another common symptom is the defoliation of the plant. The leaves will inevitably fall and this will cause the plant to end up only as a skeleton.

Results of Infestation

The infestation that is apparent in the host plant is a result of larval feeding. It is the stage at which they cause severe damages, which makes it important to execute methods of control even before the eggs hatch. The larva may appear small, but it brings serious consequences, which can be devastating for commercial growers. At its worst, this will hinder the growth of the crops and damage the quality of the output. It will make the plant unmarketable because of its unattractive appearance. The complete elimination of the foliar tissue is one of the most serious consequences. Disruption of the formation of the head is also possible.

The Foliar Tissue of Cabbage is Eliminated Completely

Cabbage Damaged by Diamondback Moth

How to Get Rid of Diamond Moth Larvae

Natural and Organic Solutions

Here are some of the best ways to control and eliminate diamondback moth larvae organically:

  • Not all insecticides are harmful to the environment. At the end of the day, it all boils down to the list of the ingredients. With this, look for one that contains Bacillus thuringiensis, which is harmful only for the pest, but not for humans and other insects in the garden. Nonetheless, keep in mind that direct and spot application is necessary to yield the highest level of effectiveness with its use.
  • The installation of floating row covers also holds a lot of promise. They will be helpful in the prevention of moths as they cover the top part of the plant, making it less susceptible to damages.
  • You might also want to resort to a variety of biological measures. Among others, one of the most effective is encouraging the presence of beneficial insects in the garden. Trichogramma wasps are some of the most popular. Despite their small size, they can kill more than 200 pests in the garden. It will kill the host before it spreads damage to the target plant.
  • Interplanting is also going to help in getting rid of diamondback moth larvae. Planting it with another crop, especially one that can resist the appearance of diamondback moth larvae, will be a promising solution. Also, the appearance of weed is a good thing.
  • It is not only insects that can help you to deal with diamondback moth larvae. There are also beneficial birds and even worms that can extend a helping hand. The presence of plants that attract birds is a good alternative. The birds will feed on the larva and will kill them before they spread damage.
  • Handpicking the larva may seem to be a tiring task, but it is one of the best ways to deal with the problem. Once you are aware of their appearance, it will be easier to spot their presence. Take them out by hand and throw in a bucket with water and mild soap.

Chemical Solutions

Chemical controls are popular, but you need to do it with caution. Insecticides with chemicals will harm not only the pest you are targeting, but even other insects. Exposure to these chemicals will be toxic to humans and the environment as well. Among others, diazinon is one of the most common and effective chemicals for the elimination of diamondback moth larvae. It is from the group of organophosphates, which targets the nervous system of the insect to cause its death.

How to Prevent Diamondback Moth Larvae

Before the eggs hatch, you should already exert conscious efforts to deal with diamondback moth larvae. With this, one of the best preventive measures is keeping the garden clean. Regular cleaning is necessary, as well as the removal of decaying vegetation. If you have plants that are susceptible to infestation, it is best to keep them in a separate portion of the garden. This will lessen the extent of the infestation. You might also consider planting crops that can resist this pest so that you won’t have any problem.

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