Mulberry shield - a sucking parasite on trees and shrubs
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An invasive pest of stone fruits, ornamental shrubs, tea plantations, and vegetable crops. Representatives of the scale insect family suck out nutrients from the plants on which they feed. In Russia, mulberry scale shield is not found. The insect belongs to quarantine organisms. With intensive distribution, they completely cover the bark of trees. Young plants are especially susceptible to negative effects, they can die. The countries of origin of the pest are China, Korea and Japan.
Description of the mulberry shield
The diet of the mulberry scale is not limited to a specific type of plant. It is found on trees, shrubs, vegetables. The pest belongs to the order of the semi-rigid winged family, scale insects. In Latin, its name sounds like Pseudaulacaspis pentagona. The oral apparatus of the sucking type of insect. Adult individuals are located on trees in a special way, females settle on the upper branches and young shoots. Males live below. With maximum infection of the plant, the trunk is covered as if with a white coating, these are densely located shields.
Scabies are characterized by sharp differences between the sexes. The body of an adult female is oval. Together with the shield, its dimensions are 2-2.8 mm. It is wingless, antennae reduced to tubercles. Its visor is white or gray. Closer to the middle or edge are the old larval skins. An unfertilized female can be distinguished by light color and bloated body. Her visor is friable. The old female has a wrinkled body, the shield becomes gray to the color of the bark.
The male has an elongated yellow body. The insect has antennae, wings and limbs. They are able to fly. Body length excluding the penis is 0.5-1 mm. The shield of the male is white, elongated, two longitudinal grooves pass along it.
Distribution area
In the 19th century the pest with planting material was brought from Asia to Europe. From Italy, it spread to other countries - Bulgaria, Germany, Hungary. Greece. Insects are found on other continents - in North America, Australia and Argentina. A quarantine object is noted near the borders of the Russian Federation - in Georgia and Azerbaijan. In Bermuda, this pest killed many oleander. In Florida and southern Georgia, Pseudaulacaspis pentagona destroyed peach orchards, consisting of tens of thousands of trees.
Attention. The pest prefers to settle on stone trees: peach, plum, cherry, apricot. Often found on apple trees, pears, lilacs, mulberries, acacia, maple. The mulberry shield feeds on vegetable crops - pumpkin, carrots, eggplant.
Pest reproduction
The mating process of the mulberry scale begins in June, during the summer period of males. In different regions, 2-3 generations can change in a year. In March, when the temperature rises to 120 overwintered, fertilized females begin to develop eggs. Ovipositor begins in late April.In a temperate climate, females bring 30-120 eggs. They are fastened in chains of 10 pieces. Development occurs under the guise of a female.
Scallop eggs are oval. Their color depends on the feed plant. Clutches of white, cream, yellow and pink are observed. Under the shield there may be masonry of the same color or mixed. Newborn larvae of the first generation have well-developed limbs and antennae. They appear in early May. The period of activity lasts from several hours to two days. Having chosen a suitable place, they begin to secrete wax threads and form a shield. After molting, they become older larvae.
By June, the larvae noticeably differ from each other. As they grow older, females lose their limbs, eyes and antennae. It is time for a massive summer of males to fertilize young females. Mating time stretches for 2 weeks. Males are deprived of the oral apparatus, they cannot eat, therefore they die soon after fertilization of the females. Females begin to lay their eggs to raise the next generation.
Interesting fact. Pest eggs and stray larvae are divided by color into two main groups - white and orange. In each group there are different shades. Color depends on gender - females are orange and males are white.
The males and females of the second generation become sexually mature by the end of July or the beginning of August. The second years of scale insects begin. Females of the second generation will live longer than their predecessors. They will remain wintering, laying the ovipositor until next spring.
Attention. In a hot climate, all life processes of scale insects are accelerated, up to four generations are replaced in one year.
Maliciousness
In the process of nutrition, the pest not only takes away nutrients from the plant, but also releases toxic enzymes. Insects settle in large colonies. They occupy young shoots, fruits and leaves. Among the signs of infection:
- Without adequate nutrition, the bark cracks on the trees, the shoots bend, often dry out and die.
- Yellow spots form on the leaves due to a violation of photosynthesis. Their subsidence is observed.
- The tops of seedlings dry out.
The multi-eating and high fecundity of females contributes to the rapid spread of pests in new territories.
In the fruits of a diseased tree, the amount of sugar decreases, the presentation of the product deteriorates, spots appear. The total yield is much lower. For people, the scale shield is not dangerous.
Pest distribution methods
Among the main ways of spreading scale insects:
- on seedlings and indoor plants infected with a pest, due to the protective color and small size, they are invisible;
- from the primary focus by wind or independently, the larvae of the vagabond are moved to neighboring plants;
- getting into new regions with fruits - this method is less common than others.
Preventive measures against the entry of a pest into the territory of the Russian Federation
The countries of the Eurasian Union have adopted special methods to identify quarantine objects:
- Visual inspection of seedlings using a magnifier. The bark is carefully studied, under which scale insects can hide.
- In summer, pheromone traps are hung in the gardens. These are plates with glue on which the pheromone of the female is applied. Traps are checked every 2 weeks to confirm the presence or absence of males of the moth shield.
Methods of struggle
It is possible to cope with the quarantine organism only with the help of a whole complex of measures. There are several ways:
Biological
One of the eco-friendly and effective ways to reduce the number of mulberry shields is the use of its natural enemies. There are 27 species of parasites and 50 predators that prey on plant pests. The most effective is Encarsia berlesei.
Agrotechnical
The main agricultural measure is the destruction of infected plants. If a pest is detected, strict control is established over the nurseries.
Chemical
To prevent the spread of infection, plants in the summer are sprayed with organophosphorus compounds and pyrethroids. In addition to chemical pesticides, biological preparations are used. In early spring and autumn, petroleum jelly is treated.
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