2. Occurrence regularity: North China completed 1 generation in two years, and the larvae overwintered in the wormhole for the second time. After spring warming, the larvae resume their activities and continue to eat. Adults emerge from late June to early July, and their life span is 15 ~ 30 days. Adults mainly lay eggs in the bark cracks at the base of the trunk and the base of the branch at a distance of 1.2 meters from the ground. Trees with large size and high age lay more eggs, and trees within 4 years basically do not lay eggs. Each female adult lays eggs 170 on average, and the egg period is 8 ~ 15 days. After hatching, the larvae eat into the cortex, which is eaten into curved grooves. Continue to eat cortex in the spring of the following year, and start eating xylem in July and August. In late June of the third year, it began to emerge as an adult. The total length of tunnels drilled by larvae in their lifetime is 50 ~ 60 cm.
3. Prevention and control methods
(1) At the end of June, 200-fold solution of 25% carbaryl wettable powder and appropriate amount of sticky mud were used to prepare mud, and poisonous eggs and newly hatched larvae were coated on the roots of trunks and branches within 1.2 meters from the ground. You can also brush or spray dry with pyrethroid pesticides such as 500 times of 50% chlorpyrifos EC or 2.5% fenpropathrin EC 1000 times. After 10, smear 1 time. This kind of insect can be basically eliminated from the garden if it continues for three years.
(2) In the growing season, if the branches are found to be rotten, remove the insect dung, insert the "stem-eating pest fumigation stick", and seal the orifice with sticky mud. Phosphine gas produced by smoking sticks can kill larvae in deep holes. A large amount of 80% DDVP EC 1500 times solution can also be injected into the wormhole to kill the larvae. Shallow larvae can dig, dig and stab with wire.
(3) Dead trees should be dug up in time and burned as soon as possible to kill larvae and insects.