Detailed Explanation of Grape Clearwing Moth Control Techniques and Methods

Growers always say that grapes suffer from many diseases, but they often overlook the problem of grape pest insects. In recent years, in the main grape-producing regions, the damage caused by the clearwing moth has been increasing year by year. So what are the control techniques for the grape clearwing moth?

1. Characteristics of the clearwing moth

Adult: about 20 mm long, wingspan 30-36 mm, body blue-black. The top of the head. The neck, both sides of the metathorax, and the joints of each abdominal segment are orange-yellow, the forewings are reddish-brown, the wing veins are black, the hindwings are membranous and transparent, the abdomen has 3 yellow transverse bands, and the male has a bundle of long hairs at the end of the abdomen.

Egg: eggs are laid singly on the branches, long oval, slightly flattened, reddish-brown, about 1.1 mm long.

Larva: 5 instars in total. The mature larva is about 38 mm long, and the whole body is somewhat cylindrical. The head is reddish-brown, the thorax and abdomen are yellow-white, and when mature it takes on a purplish-red color. The pronotum has an inverted “V’-shaped marking, with the front part lighter in color.

Pupa: about 18 mm long, reddish-brown. Cylindrical.

Damage symptoms: newly hatched larvae bore in from the base of the leaf stalk and the leaf node into the young stem, then bore upward or downward to feed; the entry point often swells and enlarges, sometimes forming a tumor-like shape, and the damaged branches are easily broken by wind and die. After the main branches are damaged, a large amount of fruit drop occurs, resulting in loss of economic benefit.

2. Occurrence pattern

The grape clearwing moth has 1 generation per year and overwinters as mature larvae inside grape vines. In late April to early May of the following year, the overwintering larvae begin to pupate. Adults emerge from May to June. Before early July, the larvae damage the current-year shoots; from mid-July to late September, the larvae mostly damage old vines more than two years old. After October, the larvae enter the mature stage and continue to concentrate toward the old vines and main trunk of the plant, where they bore back and forth over short distances in the pith and inner xylem. This widens the tunnel and stimulates the damaged area to swell into a tumor, forming an overwintering chamber, after which the mature larvae enter the overwintering stage.

3. Control techniques

1. Combined with winter pruning, cut off and remove the damaged vines and burn them in a centralized manner to eliminate overwintering larvae. From June to August, cut off the damaged dead tips and swollen young shoots and dispose of them in a centralized manner. Starting from early to mid-June, in combination with maintenance, frequently observe whether yellow fine powdery material is discharged at the leaf stalks and leaf axils. If found, apply a small amount of absorbent cotton slightly dipped in 40% Taosiben 10-fold solution. For damage to large vines, directly inject Taosiben 500-fold solution, then seal with yellow mud.

2. Biological control: during the adult emergence period from May to June, place one newly emerged female adult into a small cage made of window screening, pass a small stick through the middle, and set it on the rim of a basin filled with water. Place the basin next to the grapes, and many male adults can be trapped each night. Trapping one is equivalent to trapping a pair, and the effect is very good.

3. Chemical control: when grapes are in the tendril-extending stage and the bud stage, spray Jinming (3.2% emamectin benzoate · cypermethrin ME) 2000-fold solution or Jinweilin (5% abamectin SC) 2000-fold solution, or Lüwei (2.5% beta-cyhalothrin ME) 1000-fold solution for control, with outstanding control efficacy.