How to control the tea longhorn beetle? Master scientific methods to handle it with ease

The tea longhorn beetle, also known as the chinaberry longhorn beetle, the Zhuguang longhorn beetle, the thief old worm, etc., is distributed in Jiangsu, Anhui, Zhejiang and other places. Its larvae bore into branches and roots, causing the tree to weaken, upper leaves to turn yellow and wither, buds to become thin and sparse, and branches to break easily. In severe cases, the entire plant dies. Let us take a look below at how the tea longhorn beetle can be properly controlled!

Morphological characteristics of the tea longhorn beetle

The adult tea longhorn beetle is about 30 mm long, dark brown, glossy, and covered with dense short brown hairs. There is a longitudinal ridge in the center of the top of the head. The compound eyes are black, and the two compound eyes almost meet at the top of the head. The middle and upper segments of the antennae each protrude outward at the tip and bear 1 small spine. The antennae of the female are similar in length to the body. The egg is about 4 mm long and about 2 mm wide, elongated oval, and milky white. The mature larva is 37-52 mm long, cylindrical, with a pale yellow head, milky white thorax and abdomen, and a broad and large pronotum. The front end of the hard plate bears 4 yellow-brown patches, and the posterior margin bears 1 straight-line mark. The center of the back of the mesothorax, metathorax, and abdominal segments 1-7 bears fleshy tumor-like protrusions. The pupa is 25-30 mm long, milky white to light ochre.

Living habits of the tea longhorn beetle

The tea longhorn beetle usually has one generation every 2 years or more than 2 years. Overwintering adults appear from late April to early July of the following year, lay eggs at the end of May, and larvae begin to hatch in early June. They overwinter in late October, pupate from late August to the end of September the following year, and adults emerge from mid-September to mid-October. They do not begin to go out to mate until late April of the third year. Newly hatched larvae bore under the bark, enter the xylem after 1-2 days, and then bore downward to form tunnels, reaching more than 33 cm underground. Mature larvae rise into tunnels 3-10 cm below the surface, make oblong calcareous cocoons, molt, and pupate in the cocoons. Damage is severe in mountain tea gardens and in old tea gardens with weak tree vigor, and old tea trees with exposed root crowns suffer the most serious damage.

Control methods for the tea longhorn beetle

1. Before adults emerge, use 5 kg of quicklime, 0.5 kg of sulfur powder, and 250 g of cow glue, mix with 20 L of water into a white coating, and apply it to branches and trunks 50 cm above the ground or to the root crown, which can reduce egg laying by this longhorn beetle.

2. Timely earth up around the root zone of tea plants, and strictly prevent exposure of the root crown and adult egg laying.

3. During the adult occurrence period, use light traps to kill adults or manually capture them in the early morning.

4. Inject insecticides such as dichlorvos and dimethoate at 40-50 times dilution from the excretion holes, then seal the openings with mud, which can poison and kill the larvae.

5. Cut the roots of Stemona japonica into 4-6 cm lengths or chop the stems and leaves of Pinellia ternata, then stuff them into the insect holes, which can also poison and kill the larvae.