Gall mites are formed and mites suck up the sap of leaves, branches, flowers and fruits. The damaged branches wither, and the inflorescences and spikes are deformed and cannot flower and bear fruit normally. Young fruits are easily shed when they are killed, affecting lychee yield. Common hosts are lychees, longan, goji berries, etc.
[1] Hazard characteristics
Adult mites and nymphs suck up the sap of young leaves, shoots, spikes and young sap. The damaged part of the young leaf first appears yellow-green patches on the back of the leaf, and the damage spots are concave. As the gall mite develops harm, the affected part is yellowish brown and finally becomes dark brown; the affected leaves are also deformed, distorted like "dog ears"; when severe, the damaged leaves can dry out and wither, affecting the tree potential. After the flower organ is injured, the deformity expands and does not flower and bear fruit.
[2] Occurrence law
The mite occurs in Guangxi and Guangdong all year round, more than 10 generations a year, overlapping generations, no obvious overwintering phenomenon; generally from January to February, the mite body often winters in the late autumn shoots in the inner chamber of the canopy or at the base of the affected leaves, but its activity can still be seen when the temperature is slightly warmer. From late February to March, after winter, mites migrate to the young leaves and flower spikes of spring shoots to harm reproduction, and the reproduction volume gradually increases after early April, and the density of mites is the largest and the most harmful from May to June. It is mainly spread by wind, raindrops, seedling transportation, agricultural tools and equipment and self-crawling. Gall mites have a habit of liking shade and fearing light, so the leaves in the lower and inner canopy are vulnerable, the large trees are more seriously damaged, and the seedlings and young trees are less affected.
[3] Prevention and control methods
(1) Agricultural control: strengthen the management of the park, promote the growth of plants, and reduce the harm of gall mites. Combined with pruning and winter garden clearance, prune the branches and leaves of the gall mites, over-dense shade branches, weak branches and other diseased and insect branches, so that the canopy air circulation, sufficient light, reduce the source of insects, you can also spray the garden cleaning agent Qilin Famous Kang.
(2) Pharmaceutical control: Spray qilin royal moth for prevention and control.
