How to control longhorn beetles effectively? These control methods are worth mastering

Longhorn beetles are phytophagous insects that harm woody plants. According to their damaging characteristics, they can be divided into species that harm the trunk, species that harm the shoot tips, species that harm logs with bark, and species that harm dry timber. Most longhorn beetle species are secondary pests, and only a few species directly harm healthy living trees. Let us take a look below at the best ways to control longhorn beetles!

Using natural enemies

1. Woodpeckers and longhorn beetles are two groups of organisms that have coevolved. In 15-20 hectares of woodland, set up 4-5 nest logs with a spacing of about 100 m, clean and repair them once every autumn, and artificially attract woodpeckers to settle. For example, attract the great spotted woodpecker to control the Asian longhorned beetle (Anoplophora glabripennis) and the mulberry longhorn beetle (Apriona germari).

2. For small longhorn beetles such as the rough-sheathed double-striped fir longhorn beetle, red-margined longhorn beetle, false jewel longhorn beetle, multi-banded longhorn beetle, green poplar wedge longhorn beetle, and house longhorn beetle, adult Sclerodermus guani wasps can be released in the forest during the larval stage of the longhorn beetles. The release amount and the number of longhorn beetle larvae in the forest should be kept at a ratio of 3:1.

3. The larvae of Dastarcus helophoroides often parasitize the larvae of the Asian longhorned beetle and the spiny-horned longhorn beetle. The natural parasitism rate can reach as high as 60%, with an average of 40%. They can be protected and assisted in transfer and dispersal, and they also have parasitism ability against the larvae of the yellow-spotted longhorn beetle and the cloud-banded longhorn beetle.

4. Beauveria bassiana and Metarhizium anisopliae are used to control longhorn beetle larvae. During the larval growth period of the yellow-spotted longhorn beetle and the cloud-banded white-striped longhorn beetle, when the temperature is above 20°C, use wheat straw dipped in a small amount of fungal powder mixed with carbaryl and insert it into the insect hole, or spray the invasion hole with a spore solution of 160 million spores/ml.

Physical control

1. For longhorn beetles with a death-feigning habit, they can be manually shaken down and killed, and manual killing can also be organized by taking advantage of the habit of some longhorn beetles to rest at the base of the trunk.

2. Inject paraquat, ethephon, or chlorphonium into pine trees to stimulate increased resin secretion, attract adults to lay eggs on trap trees, and then peel the bark of the trap trees.

3. Whitewash the trunk below 2 mu above the ground to prevent adults such as the double-striped fir longhorn beetle, cloud-banded white-striped longhorn beetle, and peach red-necked longhorn beetle from laying eggs on the host.

4. Coat mulberry pruning cuts and saw cuts with asphalt, varnish, etc. to prevent the mulberry tiger longhorn beetle from laying eggs.

5. Hammer eggs and small larvae, or scrape off egg blisters.

6. Soak pest-infested wood in water or expose it to the sun. Soaking in water requires 1-2 months. After peeling the pest-infested wood, expose it to the hot sun and turn it over several times.

7. Use the vacuum nitrogen-filling method to control longhorn beetles in stored bamboo and wood equipment.

Chemical control

1. Spray branches and trunks with chemical agents. Commonly used agents include 40% dimethoate emulsifiable concentrate, 20% yiguo emulsifiable concentrate, 20% shuguolin emulsifiable concentrate, 50% phoxim emulsifiable concentrate, 40% omethoate emulsifiable concentrate, 50% fenitrothion emulsifiable concentrate, 25% chlordimeform hydrochloride aqueous solution, and 90% trichlorfon crystal at 100-200 times dilution. Adding a small amount of kerosene, salt, or vinegar gives better results.

2. For mulberry longhorn beetles that bore downward as larvae and have frass holes, use zinc phosphide poison sticks, aluminum phosphide tablets, aluminum phosphide pills, etc. to block the lowest 2-3 frass holes. Commonly used agents include 50% malathion emulsifiable concentrate, 50% fenitrothion emulsifiable concentrate, 50% dichlorvos emulsifiable concentrate, 25% phosmet emulsifiable concentrate, and 40% omethoate emulsifiable concentrate at 20-40 times dilution.

3. For the narrow-chested orange longhorn beetle and the curved-toothed soil longhorn beetle that harm the roots, pour 20-40 g of a mixture of 50% dichlorvos emulsifiable concentrate at 1000 times dilution and 40% dimethoate emulsifiable concentrate at 1000 times dilution on each affected plant.

4. For the yellow-spotted longhorn beetle and the green poplar tiger longhorn beetle that gnaw branches or rest on the trunk, spray the trunk with 40% omethoate emulsifiable concentrate, 25% carbaryl wettable powder, or 2.5% deltamethrin emulsifiable concentrate at 500 times dilution.

5. During the peak emergence period of adult multi-banded longhorn beetles, spray the planted nectar trap trees with 20% fenvalerate emulsifiable concentrate at 1500 times dilution or 80% dichlorvos emulsifiable concentrate at 800 times dilution to kill adults. In stands with a canopy density above 0.6, 741 tube smoke agent can be used to control adults.

6. For wood harvested in summer and autumn, 10% cypermethrin emulsifiable concentrate or 50% phoxim emulsifiable concentrate at 100-200 times dilution can be sprayed inward from the upper part and gaps at both ends of the stack to prevent the spruce small black longhorn beetle, spruce large black longhorn beetle, and spruce flower black longhorn beetle from laying eggs.

7. Pass sulfuryl fluoride or methyl bromide into a sealed tent. 50-70 g is needed per 1 cubic meter of wood, and it should be sealed for 5 days. This is most suitable for large-scale treatment in the harvesting forest areas of Northeast China. Wood damaged by the house longhorn beetle can be brushed with 50% dichlorvos emulsifiable concentrate at 3 times dilution.

Forestry control

1. Choose tree species suitable for the local climate, soil, and other conditions for afforestation.

2. Avoid forming large-area plantations of a single tree species. Mixed planting can use block or strip patterns.

3. Select resistant tree species and resistant strains, such as planting resistant tree species like Chinese white poplar, tree of heaven, paulownia, and black locust to prevent the spread of the Asian longhorned beetle and the yellow-spotted longhorn beetle.

4. Regularly remove sprouting branches and leaves on the trunk to keep the trunk smooth. Improve ventilation and light conditions in the forest land to prevent adults from laying eggs. Change the hatching conditions of eggs and increase the natural mortality rate of newly hatched larvae.

5. Adjust the harvesting period. In areas with severe damage by trunk longhorn beetles, small-diameter timber can be cultivated in the short term. Before longhorn beetles break out severely, the wood is not only processed and utilized in time, but the growth rate of the pest population is also suppressed.

6. Carry out the "two harvests and three cleanings" well, and promptly cut and remove pest-infested trees, dead standing trees, dying trees, suppressed trees, weakened trees, wind-broken trees, and wind-thrown trees, so as to adjust stand density and enhance tree vigor.

7. For the green poplar wedge longhorn beetle and the black-tarsus eye longhorn beetle, for seedlings and branches with galls, combine winter pruning to cut off the galls and eliminate the larvae in them, so as to reduce the overwintering pest population.

8. In forest areas where the mulberry longhorn beetle occurs, plant tree of heaven and chinaberry as repellent isolation belts. In forest areas where the cloud-banded white-striped longhorn beetle occurs, plant pond cypress and dawn redwood as blocking isolation belts.

9. Improve the monitoring and organizational system for dangerous longhorn beetles, implement responsibility systems and scientific monitoring methods. Conduct regular inspections, issue forecasts, and guide control work.