Scabbard On Indoor Plants: Description, What Is Dangerous, How To Fight

Table of contents:

Scabbard On Indoor Plants: Description, What Is Dangerous, How To Fight
Scabbard On Indoor Plants: Description, What Is Dangerous, How To Fight
Video: Scabbard On Indoor Plants: Description, What Is Dangerous, How To Fight
Video: How to Get Rid of Fungus Gnats on Indoor Plants 2023, February
Anonim
shield
shield

The scale insects belong to the order Homoptera, the family Diaspididae. All insects are coccids, and there are about 3,000 species of them, of which most are more than 2,600 species of scale insects, the rest of the insects and felt insects are herbivorous, feed on plant juices, gluttonous and dangerous pests.

All scale insects have a pronounced sexual demorphism - males and females differ in structure, very often when describing a new type of scale insects, scientists give characteristics only to females, since it is the feeding females that are visible on the stems and leaves of plants, while males live very little, only before mating, then they die. In some species of male scale insects, very little is reflected - only 2-3%, it is difficult to detect them.

What does the shield look like

Females have no legs, no wings, no eyes, no antennae, but they have well-developed piercing-sucking mouth organs. While the females are young, the scutellum is soft and insects can move. When the scutellum matures, they become immobile. Outwardly, most scale insects common on indoor flowers are similar - the body is oval or rounded from 1.5 to 2 mm in length. The body under the scutellum is whitish or pale brown; segmentation is not pronounced. The scutellum in mature individuals may cover the entire surface of the body, or partially, be highly convex, hemispherical, or flattened. The color of the scutellum is yellowish-brown, dark brown, consists of a secretory part and larval skins. In different phases of the larvae, the skins can be of different colors, therefore the shield is often of a non-uniform color, for example, the outer ring is golden brown, the central one is dark brown.Among the scale insects common on horticultural crops, there are larger species: with a pear-shaped or tear-shaped body up to 5 mm long.

In males, the mouth organs are reduced, but they have eyes, fully formed limbs and wings. The body is segmented into the head, chest, and abdomen. Males are mostly white and fluffy. Sometimes reddish, red-gray, light orange. They also have a shield, only very small.

Scale eggs are oval in shape in some species, elongated-oval, usually white or light gray, gradually darken to light brown. The eggs are very small, about 0.1-0.3 mm, and look like worms under a microscope.

The larva of the first instar is called a tramp - it has a flattened oval body, up to 0.3 mm long, yellowish in color, three pairs of legs, antennae, eyes. In many species of scale insects, by the color of the larva, one can understand into whom it will be reborn. So, in the mulberry scale insect, tramps are white and red, females grow from white, males from red.

The second instar larva is larger. Its body is white or gray, the back of the body is usually darker, reaching 0.5 mm in size. By this time, the female larva has no legs, antennae, eyes. It is distinguished from an adult only by its size and lighter color of the shield.

Image
Image

Among several thousand species there are scutes of a slightly different appearance - in some females with an almost transparent body, the scutellum is invisible, they seem to be vitreous; others have very irregular bodies, like blots; still others have a shield in deep black color. The morphological stages of development in scale insects can also differ, for example, some tropical scale insects do not have an egg stage.

It makes no sense to describe a specific type of scabbard, since seeing them in a photograph or live, you will not confuse them with anyone.

Scale development cycle

Scabbards have a pronounced life cycle. But tropical scale insects and pests of temperate latitudes have differences. They are associated with climatic conditions.

In nature, it looks like this: after mating, the female bears eggs for three months and feeds on plant sap. Three months after fertilization, she lays many eggs, according to various sources, from 250 to 500 pieces, after which she dies.

Scabbards living in temperate climates, for example, the apple comma-shaped scabbard, have the following developmental stages:

egg >> first instar larvae (vagrant) >> second instar larvae >> males and females >> egg

Females have an elongated and wide-rounded end of the shield - under it is the entire clutch of fertilized eggs, the body of the female herself simply dries up, freeing the house for the children. Winters are harsh and all egg-laying is kept under the flap. By the end of May, when the average daily temperature is about + 8C, vagrants hatch from the eggs and begin to actively populate plants, mainly young, slightly lignified branches, young shoots. The development cycle from a vagrant to a sexually mature female averages three months. Then mating takes place. The number of males in the population is approximately 20-35%. After fertilization, the males die. Oviposition begins in August. Thus, the development cycle is approximately 1 year: 9-10 months of egg maturation, 35-60 days of the larva, 3 months of the female.In southern latitudes, these species of scale insects can have time to form two generations per year.

In tropical species, this is, for example, the Californian scale insect, slightly different stages of development:

first instar larvae (wintering) >> female and male larva >> parthenogenesis * >> mating >> first instar larvae (vagabonds) >> larva diapause >> second instar male and female larvae >> male and female adults

The scutellum of females is usually round - they do not need a house for egg-laying; females of many species of tropical scutes lay larvae. Larvae of autumn birth overwinter in shelters (under the bark, leaf axils). In the spring, the tramps emerge from the shelter, quickly take a liking to the most juicy places and develop into the next stage of larvae, adults - males and females. By the time of mass maturation of females, the flight of males begins (it lasts for several days). There are few males, their number from the general population is no more than 8-9%. Mating occurs, after which the male dies.

shield
shield

* There are not so many males reflected, because the phenomenon of parthenogenesis is observed in scale insects - this is virgin reproduction, when sexually mature females grow up without fertilization (mating with males).

The cycle of development of the scabbard from the awakening of vagrants to a sexually mature female is on average a week or two. Some of the vagabonds in the middle of summer go into a state of diapause - rest. This helps the scale insects to survive adverse conditions, since in summer the tramps die from prolonged drought or heavy prolonged rains. Diapause can last from several weeks to several months. Most of the larvae turn into females. And about a month more is spent on their development. In males of some species of scale insects, the development cycle includes two additional stages: pronymphs and nymphs. Thus, the entire development cycle is approximately 60 days.

It must be said that there is no classification of scale insects by climatic types, here this is given only for clarity, in order to see the difference and diversity in the development of certain types of pests. Some scale insects, common in subtropical regions, for example, the Californian scale insect, also have an egg stage, only then a larva. Usually, oviparous scutes differ in the shape and size of the shield - it is wide enough, like a Vietnamese hat, rounded or pear-shaped. In addition, in some species of scale insects, it is not eggs that winter, but females in a state of diapause.

The number of molts can also be different: for example, females can have two stages of larvae, males - three.

From the point of view of indoor floriculture, the danger of scale insects is that due to parthenogenesis - hatching of females without fertilization, scale insects can reproduce, all year round, giving out about 5-6 generations, the process of generational change goes on continuously. At the same time, males among indoor scale insects are extremely rare, but if they appear, for some reason they are very frightening. Someone begins to think that this is an unknown, terribly gluttonous creature. In fact, the developmental cycle of scale insects, with or without males, is no different. By themselves, males do not harm plants - they simply have nothing to eat. In fact, male scale insects hatch for the sole mission of fertilization, therefore, all they have are eyes, wings and genitals.

Harm from scale insects

All scale insects cause enormous harm to plants; in orchards in 3-4 years they can completely destroy an entire fruit tree. In countries with a warm climate, in agricultural regions, when some types of scale insects (for example, mulberry) are found, strict quarantine is introduced. For this period, the export of seedlings and seedlings is strictly prohibited. Fruit trees and shrubs, stone fruits and tea plantations are treated with pesticides.

In indoor conditions, scale insects, settling on a plant, will also lead to its death in the shortest possible time. Scabbards come to our house with infected flowers from the store, planting material (soil), tramps are carried in by the wind.

shield
shield

At the site of the scabbard suction, yellow spots appear on the leaves, they grow in size as the cell sap is sucked out, then the leaf turns completely yellow or brown, curls and falls off. The plant stops growing, the branches become bare, then the whole bush begins to dry out and the plant dies. In addition to the leaves, the scabbard damages the fruits of citrus fruits (tangerines, lemons and oranges), ovaries fall prematurely, and flowers dry out.

Another sign of the appearance of scale insects is sticky discharge on the leaves. Scabbards produce a sweetish liquid - pad, it covers the stems, leaf stalks, leaves, buds and fruits. Sooty fungus and dust stick to it.

Measures to combat scale insects

As soon as you find a scale insect, something that looks like brown plaques on the stems, petioles, axils and the leaves themselves, immediately isolate the plant, and also check all the plants that were nearby. Adult scale insects are protected from insecticide by a shield, but they can be mechanically removed from the plant.

The best way to do this is to use a cotton pad and a sponge for delicate leaves or an old toothbrush (with soft bristles) for denser leaves. Moisten in soapy water and wipe thoroughly each leaf on both sides, as well as the stems. Even if it seems to you that there is still no pest on some leaf, you need to process the entire plant, otherwise one surviving larva, and after a few weeks the whole plant will be sprinkled with a scabbard again. For washing leaves, any dish detergent (aos, faerie, etc.), laundry soap, tar soap, green soap is suitable. Whip up a thick foam and leave it on the leaves for 30 minutes, then rinse with hot water (water temperature is permissible up to 50 degrees - the hand is hot). Hot shower - 2-3 minutes. If the soap and hot shower procedures are carried out once a week, then you can get rid of the shield without chemicals.

Without washing, plants that cannot tolerate this procedure must be sprayed with an insecticide. But a single treatment will not completely rid them of the scabbard. Since the female's shield protects her and the egg-laying from contact insecticides - you need to soak the plant in a solution, lower the entire crown into a bucket of chemicals, or apply watering with systemic insecticides - Aktara or Confidor - these are the drugs of choice.

shield
shield

Of the contact drugs against the scabbard, the following are effective:

  • neonicotinoids: Aktara, Tanrek, Apache, Confidor, Colorado, Spark Gold, Mospilan,
  • organophosphorus compounds: Actellik, Karbofos, Alatar, Iskra, Fufanon-Nova, Kemifos, Novaktion, Antiklesh and others,
  • hormonal insecticides, juvenoids - regulators of the growth and development of insects, for example, Admiral (pyriproxyfen),

The treatment with contact and intestinal-contact insecticides must be repeated at least three times, with an interval of 7 days, in order to guarantee the destruction of the generation of pests of larvae re-hatching from eggs. In addition, the frames and glass of the window, the window sill where the infected plant stood must be wiped with an alcohol-containing liquid or dishwashing solution.

If you are living with small children, relatives, patients with asthma or allergic diseases, if you are not able to thoroughly ventilate the apartment after applying chemicals, or if you are pregnant, do not spray plants from insecticides with insecticides, high hazard class (karbofos, actellik), there less dangerous ways, read the next recommendation.

Flea and tick remedies against scale insects

In addition to the above insecticides, flea control agents are effective against the scab, where the active ingredient is imidacloprid, and / or fipronil and cypermethrin. These are remedies for fleas, and for lice, ixodid ticks from a veterinary pharmacy: Avanpost drops, Advantiks and others.

If you have only one plant infected with a scale insect, buy the smallest dosage - drops for indoor dogs or cats. If you have a strong scaly infestation, you need to treat several plants, buy drops for large dogs weighing more than 25 kg.

How to process: dilute the contents of a pipette with drops with water, there will be no complete dissolution - you will get an emulsion. Dilute a small pipette with 500 ml of water, a large one with 1 liter of warm water. Then thoroughly moisten all plant leaves on both sides with the resulting emulsion, try to get the solution into the sinuses, cover both the stems and the petioles. Be sure to wet the top layer of the earth. Leave the solution on the plant to dry. Wash windowsills and glass with the same solution (or just soapy). When the plants are dry, thoroughly ventilate the area. It is not necessary to wash off flea and tick products, if the smell remains, then you can wash off the emulsion the next day.

shield
shield

Usually, one treatment with fleas and ticks is sufficient. But if the lesion was very strong, you need to repeat the treatment after 7 days.

If it is not possible to repeat the spraying, if there are no oil drops, there is another option: put all the flower pots in large garbage bags (120 liters), tie the bag so that it is inflated, but not completely - leave a gap. Spray the bag carefully with a flea and tick spray, such as Bolfo Spray. We do not recommend using dichlorvos - it has a very short-term effect and high initial toxicity. So, put the aerosol into the bag and press the spray for 4-5 seconds. We carefully tie the bags, leave them for a day. Pests die from suffocating.

It is best to carry out all the procedures outdoors (take out the plants in boxes, put them in a basin) or on the balcony.

The effectiveness of the actara against the scabbard

Among flower growers, there was an opinion that aktara is not very effective against worms and scale insects. Where did it come from: one of the sites described the active substance of the actara - thiamethoxam, then a quote: "The low biological effectiveness of thiamethoxam in relation to scale insects is due to the fact that it rapidly spreads through the phloem, but weakly penetrates into the sucutile cells, the contents of which are sucked out by the scale insects."

In fact, there was a typo in the text and everyone was happy to quote it. In this case, we mean the sucuticular layers - i.e. layers of integumentary tissues of leaves, stems and fruits. Indeed, thiamethoxam, when watered with actara under the root, penetrates through the phloem of leaves, but only a very small part of it penetrates into integumentary tissues. But when spraying with Actara solution, about 60% of thiamethoxam is absorbed by the main leaf tissues (mesophyll), 10% - by the epidermis, and about 30% remains on the wax layer of the cuticle. Those. the concentration of the active substance in the epidermal layer is high enough to poison the pest.

Thus, on indoor flowers, Aktara against the scabbard is quite effective, but the effectiveness will be much higher if you simultaneously pour the soil in pots with a solution of Aktara and spray it on the sheet. In addition, it should be borne in mind that the waiting period when watering the soil with an Actara solution is 2-4 days, and when spraying - from 1 hour to 1 day.

Consumption rates of insecticides against scale insects

  • Admiral - 6 ml per 10 liters of water, spraying,
  • Aktara, VDG - 8 g per 10 liters of water spraying, 1 g per 10 liters of water - watering,
  • Aktara, KS - 1 ml per 10 liters of water, watering,
  • Actellik - 2 ml per 1 liter of water, spraying,
  • Spark Gold - 1/4 tablet in a 2 liter pot - buried in the soil,
  • Karbofos - 1 g per 800 ml of water, spraying,
  • Confidor - 4 ml per 10 liters of water, spraying, watering.
  • Fufanon - 10 ml per 10 liters of water, spraying.

Folk remedies - medicinal herbs, garlic and onion infusions from scale insects practically do not help.

  • Thrips
  • Scorms
  • Mites
  • Aphids, nematodes, whitefly, miners, mushroom gnats
  • Accidental pests

Popular by topic