Soybean curly leaf borer is the main pest of soybeans, mainly distributed in north And Northeast China.
【Hazard characteristics】Larvae moth erosion of soybean leaves, flowers, and pods. The hatching larvae moth into the buds and tender pods, the bean grains of the infested pods are bitten by insects, the moths often have green feces at the mouth, and the insect moths often rot due to rain inflow, affecting quality and yield. When the larvae harm the leaves, they often spit silk to glue the two leaves together, hide in them to bite the leaf flesh, and leave the leaf veins. When petioles or young leaves are damaged, they are often bitten on one side and wilted to the point of withering. Soybean curly leaf borer harms leaf symptoms
【Morphological characteristics】Adult adults are yellow-white, with a body length of 10 to 13 mm and a wingspan of 25 to 26 mm. The head is white, slightly brown, with white scales on both sides. Characteristic yellowish brown, forewings yellowish brown, the end of the middle chamber has a white translucent near-rectangular spot, with purple folded flashes, and the hindwings are white and translucent. Adult eggs of the soybean curly leaf borer are oval, yellow-green, and have a nearly hexagonal reticule on the surface, mostly on the back of the leaves, often two at the same time. The larvae are yellowish-white, and after feeding, they can see the internal organs of the body through the insect body, which is green in color and has a green head. The dorsal plate and buttock plate of the anterior thorax are the same as the body color, and there are 4 hairy patches on the middle and posterior chest, arranged in a horizontal row. Soybean curly leaf borer larvae pupae pupae in the curly leaf, light brown, the wings are pronounced, extending to the fourth abdominal segment, pupae have two layers of thin white silk cocoons outside. Soybean curly leaf borer pupae
【Occurrence law】In the northeast, 2 generations generally occur a year, and 4 to 5 generations in the south, with 3rd and 4th instar larvae overwintering in the cocoon of the curly leaves. Overwintering adults appear in the northeast in early June, and spawn from late July to the end of August, overlapping with the next generation of eggs. Soybean curly leaf borer prefers a rainy and humid climate, and generally occurs less often in dry years. Densely grown bean fields are heavier than sparse plant plots, and round-leaved varieties are heavier than pointed-leaf varieties.
【Control method】 The following agents can be used in the peak stage of egg hatching: 1.8% avermectin emulsion 20 ml/mu; 5% fipronyl urea emulsion 25 ml/mu 2.5% high-efficiency cypermethrin emulsion 35 ml/mu; 10% high-efficiency cypermethrin emulsion 13 ml/mu; 25% insecticidal double water agent 100 ml/mu; 20% cypermethrin emulsion 3500 times liquid; 2.5% cypermethrin emulsion 2500 times liquid;
【Prevention and control method】 30-40KG of water per mu is sprayed uniformly, sprayed once every 10 days or so, and sprayed 2-3 times.