Jujube gall mite

Also known as jujube mite, jujube tick, jujube ash leaf. The insect is distributed in Dongzao jujube producing areas in Shandong Province and has become one of the main pests on jujube trees.

After the jujube tree was killed, the leaves were curled, the leaves were gray, the fallen flowers and fruits were heavy, and then the leaves fell, resulting in secondary sprouting leaves; there were spots on the fruit surface, resulting in a substantial reduction in yield and a decline in quality.

The generation of the insect varies according to its geographical location. About 10 generations a year in Zaozhuang area of Shandong Province, adult mites and nymphs overwintered in jujube scales or jujube branch bark seams, with many generations and rapid reproduction. It is characterized by high mortality, strong resistance, rapid spread, wide distribution and difficult to control.

When the jujube bud germinates in spring, the overwintering mite begins to move, gather and feed, and the density is small, and it is mostly concentrated on both sides of the three main veins in the north of the jujube leaf. The radius of activity is very small, but it has the habit of migrating by the wind, so it spreads quickly. The damage reached its peak in the middle of June. There were 100 insects and 200 insects in an 8 cm jujube leaf. Mite activity could be found on both sides of adult and nymph leaves, but mainly on the back. Force the leaves to curl longitudinally upward, turning the leaves from green to gray and brittle. According to the data of jujube research institute, when the air temperature is high and the atmospheric temperature is relatively low, it is disadvantageous to the development of the center. From July to August, mites transfer from leaves to bud scales to spend the summer, and then overwintering. For jujube trees with heavy jujube wall, the ash rate of leaves is 70%, the rate of rolled leaves is 50%, the rate of fruit is 20%, the rate of fruit drop is 10%, 15%, and the yield is reduced by 30% and 70%. Therefore, the jujube tick has become one of the only mites difficult to control in the jujube area.