What are the control methods for the cloud-spotted longhorn beetle?
The cloud-spotted longhorn beetle is a highly destructive agricultural and forestry pest, an insect of the genus Batocera in the family Cerambycidae. Its body is dark brown or grayish brown. It rests on tree trunks and large branches during the day, is attracted to light, and is active and feeds at night. After adults emerge from the eclosion holes, they prefer to rest on hosts with large crowns. Let's take a look below at how to control the cloud-spotted longhorn beetle!
Living habits of the cloud-spotted longhorn beetle
The cloud-spotted longhorn beetle rests on tree trunks and large branches during the day, is attracted to light, and is active and feeds at night, gnawing the bark of tender branches and leaves with a crunching sound. Larvae and adults overwinter in the boring tunnels and pupal chambers. Overwintering adults gnaw a round eclosion hole and emerge in mid-April of the following year, with the peak in May; when there are consecutive sunny days and higher temperatures, more adults emerge. Newly hatched larvae bore into and feed on the phloem, causing the damaged area to turn black, the bark to split, sap to flow out, and wood shavings and frass to be expelled outward. After 20 to 30 days they gradually bore into the xylem and feed upward; there are no wood shavings or frass in the tunnels. They overwinter as larvae in the first year and continue to cause damage the following spring.
Damage characteristics of the cloud-spotted longhorn beetle
In China, the cloud-spotted longhorn beetle is distributed in Shanghai, Jiangsu, Guangdong, Zhejiang, Hebei, Shaanxi, Anhui, Jiangxi, Hunan, Hubei, Fujian, Guangdong, Guangxi, Taiwan, China, Sichuan, Yunnan and other places. Adults feed on the bark of tender branches and leaves, while larvae bore into the trunk, gradually penetrating from the phloem into the xylem and boring oblique or longitudinal tunnels. The tunnels are filled with wood shavings and frass. In mild cases the tree vigor weakens, and in severe cases the entire tree dries up and dies. It can also lead to parasitism by carpenter moths and wood-decay fungi.
Control methods for the cloud-spotted longhorn beetle
1. Manual capture and killing: During the peak occurrence period of adults, inspect frequently. Taking advantage of the adults' phototaxis, reluctance to fly, slow movement, and the sound they make when disturbed, use a light to trap and kill them in the evening or capture them manually in the morning.
2. Egg-stage control: During the egg stage, look for egg grains and dig them out with a knife or crush the eggs with a hammer or similar object. During the peak hatching period, apply a 5 to 10 times dilution of 50% phoxim emulsifiable concentrate to the egg-laying notches to kill the newly hatched larvae.
3. Larva control: When frass is found being expelled from the trunk, dig out the larvae and destroy them, or inject a 100 times dilution of 50% dichlorvos emulsifiable concentrate and then seal the hole. You can also plug and tightly seal the insect holes with medicated mud or pesticide-soaked cotton balls.
4. Applying medicine to the trunk: In winter or before egg-laying, mix 5 kg of lime, 0.5 kg of sulfur, 0.25 kg of salt, and 20 kg of water evenly, then brush it onto the base of the trunk to prevent adults from laying eggs and also to kill larvae.