Problem Identifier / How to Get Rid of Broad Mites

What Are Broad Mites?

There are thousands of different species classified as mites. The majority are less than one millimeter long, which is approximately the same size as a pin head. The biggest mite is around half that size and broad mites are the smallest of all the mites.

They often cause an infection in plants, but the worst damage is sucking the nutrients out of the leaves of the plant, which disrupts photosynthesis. The growth of the plant slows considerably due to the loss of nutrients and liquids in the leaves. Broad mites carry both secretions and excrements causing damage often preventing new growth.

Broad mites are members of the Tarsonemidae family and are often found on cannabis plants. They move quickly, are incredibly small, and extremely difficult to locate.

The damage caused by broad mites is hard to diagnose. The mites only feed on newly developing and young leaf tissue. Broad mites inject a growth regulator into the plants, often resulting in a deficiency in nutrients. For this reason, broad mites need to be identified correctly, and as quickly as possible.

If not detected, broad mite damage is usually substantial. In addition to cannabis, broad mites will attack numerous other plants including peppers, cucumber, eggplant and tomato. Ornamental crops including begonia, cyclamen, azalea and gerbera are also attractive to broad mites. Plants grown outdoors in a temperate climate are generally not impacted because broad mites are unable to survive during the winter months. If not detected, broad mites will eventually destroy the plant.

Identifying Broad Mites

Adult broad mites are roughly 0.25 mm in length, with a dark green to amber coloration, a shiny appearance, and an oval shape. Their thickness is like a piece of paper or a human hair. This pest has four different stages, eggs, larva, nymphs and male and female adults. Even though the average female only lives for a period of two weeks, as many as 40 eggs can accumulate during this time. Under normal circumstances, these pests can be found in groups.

Look for the eggs on the flowers and underneath the leaves. Broad mites use sucking, piercing mouthparts to feed on the skin of the leaves and the plant cells. They are so tiny; they are not visible with the human eye. A minimum of a 60x magnifying glass is required for correct identification. The only things the human eye can see are egg clusters, a large infestation and the symptoms of broad mite damage.

When observed with a magnifying glass, the appearance and structure of broad mites is like the larger species. There is a lot of variation in color, with the most common a clear dewdrop or pale yellow. Broad mites have tiny legs, and a large, fused thorax and head. One pair of front legs are in the front, with the other at the center of the body.

The back legs are wispy, with only one pair. The back legs in the smaller males are more pronounced. The head is a medium size, with the mandible structure well defined. The mite eggs are round, translucent, and have what appears to be tiny white spots. These spots are tuffs of hair. The eggs have a diameter of approximately 0.08 mm.

Broad Mites Life Cycle

Broad Mites
Broad mites under magnification. PHOTO CREDIT Government of Western Australia

The first stage of the mite is the egg, followed by the larva and the adult. During the larvae life cycle, the pest has three pairs of legs. Once an adult, this increases to four pairs. The final pair of legs is different in the females and males. These legs are not used to walk. The larvae remain inside of the cuticle for between one and two days before emerging.

This stage is sometimes referred to as pupa, quiescent nymph, false pupa or a fourth stage. The fourth pair of legs are used by the males for carrying around the quiescent nymphs while still in the cuticle. The moment a female mite comes out of the cuticle, the mating process begins. Tarsonemid mites do not have eyes. The female mites lay most of their eggs on the surface of the fruit, or the underside of the leaves.

The oval shaped eggs are elongated and attached firmly to the surface. In comparison to the other life cycles, the eggs are large at roughly 0.07mm. The eggs have a speckling of white dots and are completely transparent.

What Does Broad Mite Damage Look Like?

The most common damage caused by broad mites includes:

  • New growth is often drooping, twisted or blistered, with a wet appearance
  • The leaves of the plant often turn up around the edges
  • Distorted and malformed growth
  • The damage is not consistent, with the worst areas where the infestation is located
  • Brown or curling leaves
  • During flower, sickly looking buds that die

Broad mite damage often mimics damage from a virus. This damage often consists of distorted and malformed growth above the surface of the soil. Broad mites prefer devouring, young plant tissue including the flower buds, young leaves and growing tips. The reason plant deformation occurs is not completely understood.

The most common theory is the mites secrete a specific substance capable of disrupting growth when sucking out the plant cells. Most of the feeding takes place on the underside, close to the leaf stalk. This usually results in the leaves curling up and turning brown. If the young leaves of the plant appear to have dark brown edges, it is a good indication that mites are present.

If the infestation if milder, the damage is generally collapsed and brown spots, or the formation of brown stripes on the leaves. These stripes form a network. If the infestation is severe, the network is incredibly dense. The green plant tissue will no longer be visible. The mites do not generally touch the main veins of the plant.

This results in the veins appearing as a green pattern against all the brown. Look for corky, brown patches appearing on the main stems and leaf stalks. The affected plants will have growing tips with a misshapen appearance. The cork formation causes a brown discoloration in different areas, with the leaves appearing as contorted. If the attack on the plant is severe, the mites can kill the growing tips.

Eventually, the growth of the plant will stop, resulting in the death of the entire plant. The development of corky tissue can also be seen on fruit. Once the pierced cells die, the appearance of corky and deformed patches is common. The misshapen fruit will then crack open where the deformation occurred. The flowers become discolored or deformed, depending on the severity of the attack.

Only a small population of broad mites are necessary to cause extensive damage to plants. Despite the severe damage to the younger leaves, the lower leaves are often unaffected. Many of broad mites gather on the underside of the newly expanding leaves. The signs of the attack will be visible for several weeks after the mites are removed or destroyed.

How to Get Rid of and Eradicate Broad Mites Naturally

The best way to get rid of broad mites naturally is:

Essential oils are often extremely effective against broad mites, which is why Trifecta Crop Control is a great solution for repelling and combatting broad mite infestations. When using Crop Control Super Concentrate, the dilution ratio is 2oz per gallon of water applied every 72 hours until the infestation is controlled, then down to once per week at preventative dose of 1oz per gallon. For severe infestation instructions, please check out our full application guidelines.

Another natural solution is predatory mites, including Neosiulus types. Placing additional predators among the plants or in the garden can substantially decrease the number of broad mites. By themselves, the predators will be unable to clear up an infestation. The other problem with predatory mites is that the remedy described above will destroy them.

When you catch an infestation early enough, you should be able to salvage your plant. But depending on the severity of the infestation and damage to the plant, you may need to remove the infested tissue.

How to Naturally Prevent Broad Mites

Broad mites can be prevented in several ways including:

  • Apply Trifecta Crop Control as part of your Integrated Pest Management (IPM) strategy
  • Quarantine plants from other spaces or grow from seed (indoors)
  • Provide a good environment for plant growth
  • Proper circulation, ventilation, humidity and temperature
  • Regular inspections
  • Air intake filters
Broad Mite Damage Pepper
Damage to a pepper resulting from a broad mite infestation.

An Integrated Pest Management program is by far your best option for preventing broad mites naturally! Prevention is always better than treatment regarding any kind of mites or pests. Applying Trifecta Crop Control as a preventative will ensure broad mites never become an issue in the first place! Apply as follows or click here to view and/or download our complete application guidelines.

  • .5oz per gallon applied once per week during veg
  • 1oz per gallon applied once per week during flower up to 2 weeks before harvest for cannabis plants. Crop Control can be applied up to the day of harvest for fruits and vegetables. Please wash your produce before consuming to remove any residual product.

When growing outdoors, additional applications may be needed depending on weather conditions. Without an IPM, preventing broad mites can be tricky. In many instances, it is impossible to determine where the infestation originated. Mites can be deposited by animals, through infected plant material, or in the wind.

One of the most common sources of an infestation is the introduction of infected clones or plants. If introducing plants from other sources, quarantine for a few weeks. If you plant from seed, you will ensure this is not an issue.

Plants also need to be grown in a good environment including circulation and ventilation, the right humidity level, and the correct temperature whenever possible, ensuring the health of the plant. Increasing the RH into the mid-50s and bringing temperatures down to the high 60s to low 70s in an indoor room cuts both spider mite and broad mite reproduction in half. Doing this while combating an infestation decreases reproduction and makes it easier to resolve.

Inspecting plants on a set schedule is beneficial because the mite infestation can be caught quickly. The sooner broad mites are found, the easier it is to get rid of them.

If you have an air intake from outside, be sure you have some sort of filter to make sure unwanted pests do not get into your growing environment.

Broad Mite Management in Greenhouse Using Biocontrol

Neoseiulus californicus is a predatory mite effective as a biocontrol option when greenhouse humidity is less than 60 percent. You can introduce this mite as a preventative measure when having difficulty finding populations of broad mites in your crops because prey is not required for survival. You need to release the predators early for controlling the populations of broad mites due to their fast reproduction with low humidity and high temperatures.

Neoseiulus can be introduced once the population has increased to help eliminate hot spots. Monitor predator activity weekly by looking for shriveled pest mites the predators have fed on and larval development within the colonies.

Use the following tips for Neoseiulus:

  • Concentrate predator release in hot spots on delivery whenever possible
  • Store at a minimum temperature of 55 degrees Fahrenheit for no more than five days
  • Mix the predators equally by rolling the tube gently
  • Predators should be poured over plant hangers or placed right on infested leaves

Defeat Pests, Mold and Mildew… NATURALLY!

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