An orchid is a beautiful plant, but at the same time capricious and expensive. That is why the happy owners of phalaenopsis and other species are so worried about their brainchild. They create all the necessary conditions for maintenance, constantly monitor the condition of the plant, periodically plant overgrown bushes, and all this only so that their orchid feels good and does not need anything.
But troubles happen that you can’t protect yourself from with the right temperature or watering regime. We are talking about the attack of pests and the development of infections in the orchid. Otherwise, these troubles are called white plaque.
What does white plaque look like on an orchid?
A white sticky coating can affect a flower in two cases: the plant has contracted an infection or it has been attacked by pests. Both the first and second are extremely dangerous for the orchid: they can quickly kill it. Treating such ailments is also quite difficult.
For your information! If the orchid has been attacked by parasites, then you should notice a white coating formed on the leaves (less often the stems), similar to cotton fibers or flakes. This means that the plant has been sick for quite some time, since the first signs of pest damage are the formation of sticky drops on the surface of the leaves.
If the plant becomes infected, the symptoms are somewhat different. Usually, when fungal infections occur, the lower surfaces of the leaf blades are the first to suffer. They become covered with a powdery coating, which grows as fungal spores develop. The danger is that the fungus grows very quickly, which means that the lack of timely treatment will lead to rotting of the orchid.
White plaque may appear in the following areas of the plant:
- on sheet plates;
- stems;
- root system.
On the leaves
Often, diseases and infections affect orchid leaves. Over time (and without proper treatment), the problem can spread to the stems, but rarely do problems start there.
Usually those flowers that do not receive proper care are at risk. Their immune system weakens and opens the way to all possible infections, among which white plaque is the most common. Lack of proper care leads to a failure of the orchid's metabolic processes, and this in turn affects the composition of the plant juice. It is because of this that various diseases and pests perceive orchids as easy prey.
Depending on the causes of the lesion, the disease may look different. Most often, the main signs of problems are:
- drying of orchid leaves and stems;
- premature completion of flowering (poor flowering);
- the inflorescences quickly fade and fall without even opening;
- Sticky drops appear on the leaves;
- Over time, the sticky drops turn into a white coating.
Important! If the plant has been affected by pests, then plaque appears on the front side of the leaf plates in the form of flakes or cotton fibers. If a plant is affected by a fungal infection, the disease will appear on the underside of the leaves and will look like a powdery coating that quickly grows over the surface of the leaf and stem.
On the stems
White bloom rarely appears on orchid stems. Most often, it moves there in the later stages of disease development from the leaf blades. It usually looks like this:
- sticky drops of sweet secretion;
- white powdery coating with the texture of cotton fibers;
- gray-green mold.
On the roots
Orchid roots in most cases are subject to infectious attack. This part of the plant is difficult for pests to access, so they prefer something simpler, such as leaves.
The main problem that orchid owners may encounter is mold. This fungal infection looks like a fibrous coating that can appear on all parts of the plant (except inflorescences). Mold reproduces with the help of spores, so the disease spreads quickly, affecting all healthy areas in a short time. If a fungus was brought into the house, expect complete infection of the plants.
The color of mold can vary:
- light gray (this variety is called white);
- green;
- black.
Outwardly, it looks like a shaggy crust that covers the roots of the plant. This disease is also dangerous because it can hibernate for a long time somewhere in the roots of the orchid. As soon as the external environment allows, the fungus immediately wakes up and begins its active activity.
Important! Mold can infect all parts of the plant as it spreads through the voids between the bark of roots and stems and along the surface of the soil.
Symptoms of pest damage
This pest is difficult to confuse with anyone else. There are several signs of the appearance of an uninvited “resident” when it is difficult to detect:
- sticky leaves and white coating on the orchid;
- motionless white tubercles (clutches in which females hide);
- sticky drops on stems and leaves;
- mold or the beginning of rotting of the plant;
- changed size and color of its various parts;
- “marbled” leaves interspersed with pink and yellow.
Why might it appear?
There are many reasons for the appearance of a harmful white coating on an orchid. Most often the plant gets sick:
- with improper care;
- non-compliance with temperature conditions;
- improper watering.
It is also worth noting that the development of the disease may be a consequence of contamination of the substrate. So thorough disinfection of all tools and soil is a necessary condition for normal plant growth.
Improper care
These include many factors. Most often, the plant suffers in winter, since at this time the amount of natural light decreases, the air becomes drier, and water stagnates in the soil.
Common consequences of improper care are rotting of the root system and the formation of fungal plaque on the roots, leaves or stems. All this happens due to waterlogging of the soil.
As a result, the orchid:
- dies;
- attracts pests;
- rots, infecting the substrate.
Important! When watering, focus on the consistency of the soil in the pot, and not on the time interval between waterings. If the soil is dry enough, you can add a new portion of water.
Careful adherence to the watering regime must also be accompanied by strict adherence to the temperature regime, since mealybugs, which are dangerous for orchids, feel quite comfortable in a dry and warm place, but are afraid of moisture. To keep the roots healthy, but at the same time protect the leaves and stems from pests, wipe the leaf blades with a damp cloth and use spraying instead of watering.
The temperature in summer should remain within +18...+30 degrees, in winter +20...+23 degrees is sufficient. Air humidity should be at least 55%.
Timely removal of dried parts of the plant is also important. This helps protect the orchid from the spread of pests. Standard pruning is excellent prevention.
Infection in the soil
Sometimes the cause of orchid disease can be contaminated soil. That is why most flower growers advise purchasing ready-made soil mixtures only in trusted stores.
If you prefer to prepare the substrate yourself, be sure to disinfect:
- Take pre-prepared bark for the substrate.
- Dry the bark in the oven at +60 degrees for 15–20 minutes so that all possible pests and bacteria die.
- Disinfect the plant seedlings before planting them in sterile soil.
After replanting the plant, throw away the soil from under it, especially if the plant is sick with something. Do not replant other flowers in such soil under any circumstances, as there is a high risk of their infection and death.
Powdery mildew
This disease most often affects the leaf blades of orchids. Primary signs of the disease appear only in small areas. This is why most flower owners do not notice them. Over time, the affected area increases significantly.
The carrier of powdery mildew is powdery mycelium, which is capable of multiplying to incredible sizes in a short time under favorable environmental conditions. Outwardly, it looks like the surface of a sheet sprinkled with flour.
Causes of powdery mildew infection:
- sudden changes in temperature;
- waterlogging of the soil;
- lack of timely therapeutic or preventive measures.
Lack of treatment for such an infection leads to the death of the plant.
Mealybug
Mealybugs, otherwise called hairy lice or felt lice, belong to the family of hemipteran insects, which have nothing in common with the worms we are used to. Many inexperienced gardeners confuse scale insects with scale insects, although these insects are not even similar in appearance.
The mealybug has an oblong body 2–6 mm in length, beige or white in color. Their body is completely covered with a waxy coating, reminiscent of ordinary flour. They have bristles on the sides and two pairs of long hairs on the back.
There are many varieties of these pests in nature. Only three species pose a danger to orchids:
- Bristly. Their females have a red body tint, dusted with waxy “flour”. Males resemble flies in appearance and are capable of flight.
- Citrus. The body of females has a pinkish color and a light coating. They are the ones who leave sticky drops (sticky sweet secretion) on the surface of orchids. Males are brown in color and can fly.
- Seaside. The body of females is colored in gray-pink shades. Males have wings that allow them to fly from place to place.
Important! This type of pest can also reach the roots of the orchid. In addition, they secrete a special secretion that stimulates the formation of fungal infections and develops bacterial resistance to chemicals.
What can a powdery mildew and mealybug infestation lead to?
If the leaves or roots are covered with a white coating due to powdery mildew, the flower must be treated immediately, since fungal spores spread extremely quickly . Spots will very soon appear on the upper side of the leaf, leading to deformation and rotting; the same thing threatens the roots of the orchid.
The most dangerous parasite for a plant can be considered a female mealybug. They attach themselves to a flower and suck the juice out of it, while injecting poison. The insect's nest is shrouded in a white, airy coating, around which one can often find white dots - the larvae of the parasite.
In addition, the waste products of the mealybug, which can be found in the form of sticky spots, become an excellent breeding ground for fungal infections.
What is the danger of sticky coating?
Regardless of what caused the orchid to become infected, lack of proper treatment can lead to its death. Fungal infection will cause rotting of the root system and death of the flower.
When infested with mealybugs, the female insects pose a particular danger, since it is they who, with the help of their mouthparts, gnaw holes in the orchid, stick to it and suck out the life-giving juice. These parasites prefer to build their clutches in the recesses of leaves, which look like small lumps of cotton wool.
Pests quite easily move from the flower to pots, window sills and windows. There they cover everything with their cobwebs. It closes the stomata of plants, preventing them from breathing, and outwardly it looks, to put it mildly, unaesthetic.
Female scale insects are excessively fertile. They are capable of laying eggs four times a year. The larvae hatch from the clutch after 10 days. The young are very nimble: individuals quickly navigate the terrain, find a place to feed and begin to develop. When fed, they grow quickly, filling ever larger areas with their colonies. If left untreated, such rapid reproduction will destroy the plant.
The appearance of scale insects may be due to the following reasons:
- the plant was previously weakened by attacks from other parasites;
- the orchid received improper care;
- the soil was contaminated from the beginning or had not been changed for a long time and therefore became depleted.
Types of scale insects
Among the many representatives of the scale insect family, there are several species that cause concern to lovers of indoor flowers.
- Bristle mealybug (Pseudococcus adonidum) - damage to the plant is caused by females and larvae of the insect. The body of adults is orange or pink. It is covered with a powdery coating. Females reach a length of 5 mm, males are smaller. The pest produces a large amount of honeydew (sweet secretion), which causes the appearance of fungus. This species is viviparous; its representatives actively spread throughout the orchid.
- Seaside mealybug (Pseudococcus affinis) – this species is most widespread. The body of the female is elongated, the color is pinkish-gray. A powdery coating is clearly visible on its surface. Males grow up to 2 mm and use wings to move. Females do not fly, their length is 3-4 mm. Well-developed legs allow them to seek out the best places to feed and lay eggs.
- Citrus mealybug (Planococcus cirti) – The color of the pest ranges from yellow to brown. The body is covered with a waxy coating, with thick bristles visible on the sides. Females leave behind a sticky, sweet honeydew.
Information. More than 2,000 species of mealybugs have been found in the world. Most prefer tropical latitudes; 300 species are found in Europe.
How to treat the disease?
If you notice signs of infection in your orchid, immediately disinfect the plant:
- Remove all flower stalks (regardless of whether they have lesions or not).
- Dissolve 15 ml of liquid soap in a liter of clean water and mix well.
- Using a cotton swab, wipe the plant with the soapy mixture, carefully removing any insects visible on the leaves and stems.
After this procedure, quarantine the plant for several days. Watch him. If its condition has not worsened, return the orchid to its original place and pay more attention to caring for it.
Important! In case of fungal infection, you need to transplant the orchid into a clean substrate and a new pot. After removing the plant from the old container, you need to rinse all the roots with warm water (+35 degrees), and remove the diseased parts. In case of infection, you need to soak the root system in a fungicidal solution for 15 minutes.
Chemical and biological agents
Pest control is in many cases more difficult than fungus control. The mealybug clings to its territory and will not leave it so easily.
The most effective drugs that can kill the parasite are:
- Fitoverm;
- Bankol;
- Mospilan;
- Aktara.
All of the listed insecticides fight both adults and larvae. After treating the plant with the preparation, close it with a plastic bag and leave for 25–35 minutes. This will help enhance the effect of the product. Do not carry out treatment in a room where someone lives: take diseased plants outside or at least to an uninhabited balcony.
Observe precautions when working with chemicals: protect all exposed areas of the body, face, eyes from accidental contact with the composition, do not drink, smoke or eat while processing plants.
Treatment with traditional methods
Traditional recipes will help cope with pests only in the initial stages of disease development. Don’t expect magical results from them if the parasite has already captured more than 50% of the flower.
The most effective means:
- Garlic infusion. Take 5 garlic cloves, pour 1 liter of boiling water and leave for a day. Strain the finished mixture and treat the affected areas of the flower with it.
- Onion infusion. Peel and chop one medium-sized onion. Fill the raw materials with warm purified water, leave the mixture to infuse for 2-3 hours. Strain the broth and spray the orchid with it.
- Pepper infusion. Take 50 g of hot pepper, pour 500 ml of boiling water over it, then place on the stove and boil for 5 minutes. Cool the finished mixture and strain. Treat the diseased plant with the decoction.
What to do with whiteheads?
The only possible method of getting rid of white sunken spots or white dots on an orchid is careful care:
- normal watering mode;
- timely treatment of pathologies.
If you monitor the condition of your orchid, the consequences of the disease will soon disappear.
Reasons for appearance
The main reason for the problem is the weakened immunity of the plant itself, caused by errors in care or maintenance.
Too dry air in the room provokes the appearance of pests, and too humid - fungus. Cold and lack of lighting are dangerous. Overwatering, stagnation of water in the substrate and moisture entering the leaf axils lead to putrefactive processes and favor the development of powdery mildew. Abuse of nitrogen fertilizers significantly worsens plant immunity. Infection can occur through the soil if it has not been disinfected before contact with the orchid. A fertile environment for the development of pathogenic microorganisms is fallen flowers that are not removed from the pot in time and leaves that have withered from old age.
Fungal spores can be carried by wind and insects flying into the house. Recently acquired flowers sometimes become a source of infection or parasites. To prevent them from infecting the rest of the collection, they should initially be quarantined.
Preventative measures to prevent the flower from becoming covered with white fluff
In order to avoid such problems with your orchid, you should follow some preventive measures:
- Water the orchid only when the soil is completely dry.
- Periodically give the flowers a warm shower to remove excess moisture from the leaf plates.
- When temperatures drop, reduce the amount of watering.
- When daylight hours are shortened, use phytolamps.
- Observe temperature conditions.
- Carry out preventive treatment once every three months.
- Replant orchids only in proven soil.
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Chemicals: how to treat?
Modern manufacturers present a variety of chemical preparations that can effectively eliminate pests on indoor plants. The advantages of using them are as follows:
- the ability to quickly penetrate orchid juice, making it poisonous;
- creation of reliable protection for a relatively long period;
- the ability to eliminate parasites in hard-to-reach places.
Disadvantages of chemicals:
- high toxicity to people and pets;
- causing addiction of some drugs in mealybugs.
The most popular chemicals among gardeners include:
Aktellik
Created on the basis of pirimiphosmethyl. Getting into the body of scale insects with plant juice, it has a detrimental effect on them.
Due to high toxicity, it is not suitable for preventive treatments.
Fitoverm
Insectoacaricide of biological origin. Due to the lack of toxicity, it is ideal for treating indoor plants. Has a contact-intestinal spectrum of action.
Aktara
Made from thiamethoxam. Penetrating inside the leaf plates, it infects pests during feeding. Characterized by high power of action. Involves processing up to 4 times with an interval of 10 days.
Calypso
Created on the basis of thiacloprid. Blocks the transmission of nerve impulses of parasites, which causes their death. It is considered an intestinal and contact insecticide.
Treatment with the drug is carried out up to 2 times with an interval of 40 days.
Bankol
A drug based on bensultap. Kills pests through direct contact or feeding. Not recommended for use during flowering.
Mospiplan
Contains acetamiprid and is not addictive to parasites. It has a contact-intestinal effect and provides protection for 3 weeks.
Main mistakes during treatment
When trying to save an orchid from white plaque or white mold, inexperienced gardeners may make some mistakes that should be avoided :
- Creating high humidity in a room with a diseased plant;
- Placing the diseased plant in direct sunlight to dry the soil;
- Use of large doses of chemicals.
ADVICE! When treating a sick orchid, the first rule is not to overdo it with measures and doses. This will help avoid chemical and sunburn and other unforeseen troubles.
