Control of gall mites in Litchi

Litchi gall mite, also known as litchi gall wall lice, litchi hairy spider, the injured leaves are called felt disease. To harm litchi and longan. Adult mites and nymph mites are harmful to tender shoots, leaves, flowers and young fruits, sucking liquid juice. The injured leaves first appear yellow-green patches on the back, the damage spots are sunken, protruding on the front, and the depressions are thickly fluffy, shaped like blankets, that is, the so-called galls. The surface of the injured leaves was twisted and uneven, and even withered and withered. After the flower organ is damaged, the deformity expands into clusters and will not bear fruit.

Life habits: more than 10 generations a year, with adult mites and nymph mites overwintering among the gall villi. The insect population density is the highest from May to June, and the damage is more serious in this period of the year. The leaf surface of the victim is prominent, and the flower organ of the victim is enlarged like an inverted bell. The population density was the highest when the gall grew within half a year. Gall mites live among the gall villi, are more active when exposed to sunlight or when Rain Water invades, and wriggle up and down between the villi. Eggs are laid at the base of the villi. Gall mites like shade, dense crown, poor light environment, the lower part of the crown and the interior, the density of the insect population is higher, and the dorsal leaf is the most common on the leaf. Gall mites can be spread by seedlings, insects, instruments and wind. The seedlings of litchi and longan are often propagated by high-altitude striping, so seedlings are the main way for gall mites to spread.

Prevention and control methods: 1. Combine pruning and pruning in winter to cut off the damaged branches and leaves. two。 Spraying Baume 0.2 degree stone sulfur mixture can also be used with a mixture of 50% dichlorvos emulsion, 40% dimethoate emulsion and water (with a ratio of 1: 1, 1: 1, 1: 1, or 800 times of triclofenac emulsion) during the initial formation of galls on flowers and leaves from February to March. 3. When transporting seedlings, check and remove insect leaves to prevent pests from spreading to the new area.