Methods for the prevention and control of pests and diseases in succulents
Today, the editor will elaborate on some knowledge about succulents, the prevention and control methods of pests and diseases in succulents, and introduce them to you.
In the transition period from summer to autumn when the weather changes from hot to cool, it is the season when pests and diseases are prone to occur. Generally, the periods when the weather changes from "cold to warm" and "hot to cool" are the most likely times for the sudden outbreak of pests and diseases, usually referring to the periods of transition from summer to autumn and from winter to spring when they are more likely to break out. During these two periods, a large number of eggs will hatch.
Among them, there is a pest that is extremely widespread and has been a headache for many plant lovers, that is, "mealybug" ( shown in the picture below). In order not to use disgusting internet pictures, I just sketched it randomly. It should not be so easy to make people's skin crawl. I hate the powder-covered insects the most, such as moths. As the saying goes, when geese pass, they leave their voices; when insects pass, they leave "powder..."
Mealybug is a small sap-sucking insect of the Homoptera (Homoptera) and Pseudococcidae (Pseudococcidae) families. Its body surface is covered with white or creamy wax, resembling white powder. This "Homoptera" is full of some notorious pests. For example, scale insects, aphids, whiteflies, etc., all belong to Homoptera. Moreover, these insects have the following characteristics:
1. Slow movement (speed 0)
2. Prefer to secrete waxy, powdery, or胶状 substances (magic 3)
3. Thick shell, strong resistance to drugs (armour 2)
4. They all rely on needle-like mouthparts to suck the sap of plants for survival (healing medicine 1)
However, fortunately, these little monsters are not boss-level, and they can be dealt with a bit of effort.
Temperature affects insects: (for now, let's just discuss mealybugs, and other common pests will be studied later)
In the past few weeks, when the weather was cooling down, I had a mealybug outbreak in two potted plants at home (the soil of those two plants was mixed randomly and had not been disinfected at high temperature). However, after a week of continuous spraying, I finally completely suppressed the attack of the insects. After special observation and consultation of relevant information, it was found that mealybugs are indeed very sensitive to temperature. Different ambient temperatures have a significant impact on the growth, survival rate, and egg production of mealybugs. The survival rate of adult female mealybugs decreases gradually with the increase of temperature within a certain temperature range. High temperature has a certain inhibitory effect on the egg production of adults, and long-term high-temperature treatment significantly reduces the egg-laying rate of female insects. In the transition period from summer to autumn, the day-night temperature difference falls back to the suitable temperature range for mealybug hatching, so it is easy to have a large-scale pest outbreak at this time. Of course, the high temperature period of summer is definitely not suitable for the growth and development of mealybugs.
Within the range of 22-28 degrees Celsius, it is the most suitable temperature range for the growth of mealybugs. In this range, the development cycle of mealybugs decreases with the increase of temperature, and the survival rate increases with the increase of temperature. The most suitable temperature range for egg hatching and development is 22-25 degrees Celsius. Under the continuous temperature of 33 degrees Celsius or above, a large number of female adults will die.
On average, a female insect lays 400-500 eggs, and each egg sac contains 150-600 eggs. Most of them hatch into female insects, and the proportion of male insects is very small. The "egg stage" of mealybugs is short, which is also one of the reasons for the high hatchability. The eggs can hatch in 3-9 days, which is why you suddenly see your plants covered with them overnight. In cool areas, eggs and larvae overwinter in plants or soil. In warm and suitable areas, they can reproduce at any time of the year!
After the eggs hatch, they enter the nymph stage. The nymphs can start feeding and harming plants shortly after they hatch. The nymph stage lasts for 22-25 days. What is a "nymph"? A "nymph" refers to the juvenile stage of "incompletely metamorphosed insects", at which time wings and reproductive organs are not fully developed. This means that after these 25 days, the nymphs develop into adults and can mate and lay eggs. Under normal conditions, a generation can be produced in 25-30 days, and 12-15 generations can occur in a year! This calculates to a huge number of descendants! Because they can reproduce all year round, the population increases rapidly, and the generations overlap seriously.
Mealybugs prefer to absorb the youngest parts of the plant, so you always find them near the growing points and buds. Occasionally, you find them on the stems because they are crawling up from the soil... They are slower than snails. Some lazy insects just stay in the soil and absorb the sap from the plant roots. If you dig into the soil and find white powder or white fluffy substances, that is the secretion of mealybugs, and you will definitely find translucent larvae or eggs inside. The diameter of the eggs is very small and can be observed with a magnifying glass. One thing that cannot be ignored is that many adult insects often lie on the back of leaves or in the angle between leaf stalks, which are not easily detected. When checking the above-ground parts, you should not just check the growing points.
Infested plants will grow weakly, slowly, or stop growing, and dry up due to water loss. It can also cause flower buds and leaves to fall off. In severe cases, the plants will die in large numbers.
Defense and attack strategies:
One, disinfection of flower pots and soil
The best method is to prepare for rainy days in advance. However, many plant lovers often ignore this point or don't take it seriously. That is the high-temperature disinfection of flower pots and soil, which is definitely the best defense. No matter how clean and hygienic the soil bought from the flower market is, whether it is imported or not, you have to disinfect it at high temperature. This lays a solid foundation! The first effect of high temperature is to kill bacteria, and the most important second effect is to kill insect eggs. The elimination of bacteria is only temporary because as long as the temperature and humidity are suitable, a large number of bacteria will still爆发 in the flowerpot because bacteria are无处不在. However, the elimination of insect eggs is strategic! It is impossible to rule out that some insect eggs that are difficult to see with the naked eye are偶然传播 or spread by wind, but compared to the number of insect eggs in the soil, it is already a small problem!
My usual method is to disinfect in the microwave oven at high temperature for 10-15 minutes. Some plant lovers dislike soiling the microwave oven or making the kitchen full of unpleasant "soil smell". Therefore, it is recommended to buy a large bowl that can be heated in the microwave from the daily goods market, and then pair it with a similarly sized shallow plate as a cover, as long as the diameter can fit in the microwave. That's OK! Put the soil in, cover it, and there won't be any smell, and no harmful substances will evaporate and adhere to the microwave. Of course, after heating, you need to open it and let it dry and cool for a while. You can't immediately pot the plants, because sometimes the surface soil cools down, but the soil underneath is still hot, which can scald the plants. However, this method is only suitable for the disinfection of a small amount of home flower soil, and it is not practical for a large area of soil.
Another relatively safe and convenient method is to use boiling water for disinfection. You can use a vegetable washing strainer to hold the planting material, put a basin under it to catch the water, and then pour boiling water evenly on the planting material, which also has the effect of high-temperature disinfection. Then you need to wait for the planting material to naturally dry before using it. There is no need to say more about this, as everyone knows how to operate it.
You can also find an open area and spread the planting material evenly on the ground to disinfect it with sunlight, but this method is not as thorough and reliable as the previous two methods.
Two, spraying insecticides
This is an offensive move against insects. However, even if the preliminary disinfection work is done well, it is impossible to completely eliminate insect eggs. Wind transmission, animal transmission, the purchase of new plants, and the entry of insects will all cause pest problems again. Therefore, insecticides are also essential at home. But any insecticide will definitely cause some harm to the human body, especially when the space at home is small, the ventilation is poor, and there is no separation between the balcony and the indoor, extra caution must be exercised when spraying insecticides. Moreover, if there are children at home, it is best to move the insecticide spraying to the outdoors.
The preliminary protective work of spraying insecticides must be done, which is also a protection for oneself and is very important!
I usually use "Abamectin" as the insecticide, and I'll take this insecticide as an example. I personally think this medicine is relatively effective. The recent mealybug outbreak was dealt with using it, and now there are basically no traces of insects. Flower markets usually sell it for 10-15 yuan per bottle, which is a 50 ml bottle. Don't get ripped off!
"Abamectin" is an agricultural and veterinary insecticide and miticide. Abamectin has contact, stomach, and fumigation effects on pests, but the lethal effect is slow. After insects come into contact with the pesticide, they will show symptoms of paralysis, stop moving, and stop feeding, and die 2-4 days later. Therefore, you don't have to worry about the ineffectiveness of the medicine at the beginning. In about four or five days, the pests will gradually disappear.
This pesticide has less residue on the plant surface. After喷施 on the leaf surface, it can quickly decompose and disperse, and the active ingredients infiltrated into the thin-walled tissue of the plant can remain in the tissue for a long time and have a传导 effect, which can kill insects that feed and harm the plant tissue. It has obvious effects on mealybugs, aphids, red spiders, leaf miners, etc.
Compared to insecticides like "Furadan", "Abamectin" is considered a relatively low-toxic insecticide. But any insecticide should not be underestimated, and the necessary protective measures must be taken, after all, it is "poison"!
Three, drenching the roots
After spraying the surface of the plant, you can use a slightly higher concentration of insecticide to water the potting soil. This step is to poison the nymphs and adults attached to the soil and roots.
Four, precautions
1. When spraying, be sure to spray evenly and meticulously.
2. Do not mix with alkaline pesticides.
3. Do not spray in the middle of the day in summer.
4. Store away from high temperature and fire sources, and out of reach of children.
5. Avoid contact with the skin or溅入 the eyes. If this happens, rinse immediately with water and consult a doctor.
6. After spraying, the plants should be kept away from the upwind position in the house. If possible, place them outdoors. Wait for the pesticide to take effect and the pest problem to明显消失 before moving them back.
7. Do not spray insecticides before meals. After spraying, remember to wash your hands, and do not eat for a short time.
There is another method that can increase the efficacy of the pesticide and reduce harm to the human body, which is to cover the flowerpot with a transparent plastic bag after spraying the pesticide (as shown in the picture above). This can enhance the fumigation effect of the pesticide and prevent the pungent smell from spreading. However, you cannot keep it covered all the time. Plants also need to breathe.
Finally, when the season of easy outbreak of pests and diseases is approaching, it is best to sprinkle some "underground insecticide granules" on the soil surface or below the soil to prevent problems before they occur.
Dealing with flying insects:
In addition to those slow-moving insects that lie on the plants and absorb plant sap, there is another type of insect that is very annoying, and that is flying insects. They not only harm plants but also cause trouble for people. Imagine a scenario where you have guests at home and small flying insects are flying around you, which will certainly make the host very embarrassed.
Firstly, if you find that the number of flying insects has increased rapidly recently, you need to sprinkle "underground insecticide granules" evenly on the surface of all potting soil to prevent female insects from laying eggs in the soil again and to inhibit the hatching of larvae, thus controlling the source.
Then, for the adult insects that have already hatched, we need to eliminate them step by step. It is not recommended to spray insecticides like "Raid" all over the house. One, the concentration of insecticides in the air is too high, which is harmful to the human body. You might kill the insects before you die... Moreover, this oily insecticide sprayed on the plant leaves is also harmful to the plants themselves because it is not a pesticide for flowers.
It is recommended to use the phototaxis of flying insects to "lure and kill" them.
1. At night, hang a light on the balcony and place a sticky fly trap or a basin of water under the light.
2. Buy an "electronic mosquito killer" and place it on the balcony.
There are many different types of "electronic mosquito killers". There are electric shock types, sticky trap types, and air吸入 types. The electric shock type makes a crackling sound at night. The air吸入 type attracts flying insects with light, heat, carbon dioxide, and water vapor, and once they fall into the trap, they become trapped and eventually dehydrate and die.
3. There is also a "bug zapper" that can attract and kill flying insects using the phototaxis of insects.
The above sharing is the full content of the prevention and control methods of pests and diseases in succulents. Green plant lovers can refer to this for reference.