Transmission ways and control measures of pear scale

I. Distribution and harm

Pear scale mainly harms many kinds of fruit trees and trees in Korla, such as pear, apple, apricot, peach, Hawthorn, grape and poplar. The dense groups of insects live on the upper part of the crown and the branches of the inner chamber, and there are more smooth branches and sunny sides. The insect population density on the 5-year-old branches was the highest, and most of the 1-year-old branches were concentrated around the bud base.

Pear scale sucks the sap of branches, leaves and fruits with female adults and nymphs. Twigs and leaves withered and fell off; purple sunken spots appeared after fruit damage, forming malformed fruit; after branch damage, cork was corked, phloem and vessel tissue died, light weakened tree potential, heavy branches withered.

II. Life history and habits

The pear scale has three generations a year in Korla, overwintering with 1-year-old and 2-year-old nymphs on the branches. When the sap starts to flow in the spring. The overwintering nymphs began to feed, and the male adults appeared in the middle of May, and the males died after mating. The fertilized female adults began to give birth to the first generation nymphs at the end of May and the beginning of June, the peak period was in the first and middle of June, and the final stage was in the middle of July. The first generation of female adults began to reproduce in late July, reached its peak in early August, and still had a small amount of nymph activity in early September, while the second generation of female adults gave birth from mid-September to mid-October.

III. Ways of transmission

1. Wind propagation

Because the pear round scale is small, it meets the wind during the reproductive peak and spreads to the pear orchard through the wind.

two。 Spread of branches, leaves and fruits

From the tree body with insect branches and leaves and fruit drop spread to the area where the damage did not occur.

3. Migration propagation

The male insects of the pear scale spread the damage by migrating at close range.

4. Spread of immature organic fertilizer

Fruit growers fertilize pear trees with weeds in pear orchards and feed livestock with immature wormborne branches and leaves, thus spreading the harm.

5. Pruning tool propagation

The harm can be spread by pruning saws and grafting knives.

IV. Prevention and control methods

For trees with only 1 or 2 branches with insects, the method of manually brushing the overwintering nymphs can be used, or the insect branches can be cut off and transported out of the orchard to burn. For individual taller trees, during the sap flow period, the rotten cotton wadding soaked in 30-50 times faster killing liquid was tied to the trunk scraped clean and warped, with a width of 20-30 cm, covered with plastic film and fastened to prevent the liquid from evaporating quickly. Repeating 2 or 3 times before the end of April can effectively control the harm of pear scale.

In the pear orchard with large occurrence area and serious damage, the pear orchard was sprayed with 5 degrees Be stone sulfur mixture or 100x melting to kill scale mites in late March. In the first ten days of May, before the wax shell of the overwintering nymph is formed, and from the first ten days of June to the middle of July, the emergence stage of the overwintering nymph and the reproductive period of the female are favorable opportunities for control. It can be sprayed with 1000 times liquid of 40% speed culling, 1500 times of 25% Eckas or 800 times of 1000 times of scale, which has good control effect.

During the growth period, try to avoid the use of broad-spectrum pesticides with long residual period in order to protect natural enemies.