Control of tea caterpillar

Tea caterpillar is also known as tea yellow moth and swinging head worm. It belongs to the family Lepidoptera. It is distributed in all the tea-producing provinces in China, and it is an important pest in tea areas in China. Mainly harm tea, but also harm Camellia oleifera, oranges and so on. The young larvae bite on the old leaves of tea trees to form a semi-permeable film, and then bite on the tender shoots to form leaves. Larvae cluster damage, often tens to hundreds of heads gather on the back of the leaves to feed. When it is serious, the leaves of tea trees are completely eaten up.

The morphological characteristics of the adult are about 10 mm in length and 28 mm in wingspan. The female moth is slightly larger with yellowish-brown wings, while the male moth is slightly smaller and yellowish brown. There are two yellowish stripes in the middle of the forewing and two black spots in the yellowish area of the wingtip. There are yellow hair clusters at the end of the female moth. The eggs are laid in blocks, the egg blocks are oval and covered with yellow hairs. The mature larva is about 20 mm long and yellowish brown. The three segments of the chest are a little smaller. There are 8 yellow (Prophase) or black hairy tumors in each segment, with yellow-brown poisonous hairs on them. All are also densely covered with yellow poisonous hairs of uneven length. The pupa is yellowish brown, about 9 mm long, with a thin yellow silk cocoon outside, and the cocoon is about 13 mm long.

The occurrence law is multi-generational, and the occurrence algebra is different from place to place. There are three generations a year in Hunan, overwintering with egg blocks on the back of the old leaves. The damage periods of larvae of each generation were from April to May, June to July and August to October, respectively. It usually occurs heavily in spring and autumn. After maturing, the larvae formed cocoons and pupated under the surface of deciduous soil in the rhizosphere of tea bushes.

Prevention and cure method

The main results are as follows: (1) from November to April of the following year, the overwintering eggs are removed manually.

(2) the newly hatched larvae of each generation were removed.

(3) during the occurrence of adults, light lights to trap moths, or sex hormones are used to trap and kill males.

(4) combined with ploughing deep cocoon pupae.

(5) Biological control. Tea caterpillar black egg wasp and cocoon wasp were used to control eggs and larvae. Spraying Bacillus thuringiensis or Dendrolimus punctatus nuclear polyhedrosis virus in larval stage.

(6) Pesticide control. During the larval stage, 90% trichlorfon, 80% dichlorvos, 50% malathion, 50% fenitrothion, 50% cyanofos, or 10% dichlorophenol, 20% fenpropathrin, 2.5% deltamethrin, or 1000 times of larval gills were sprayed.