Cotton leafhopper

Scientific name Empoasca biguttula (Shiraki) is a Homoptera, leafhopper family. Alias ​​cotton leafhoppers, cotton dust, two floating dust, eggplant leaves. Widely distributed throughout the country. The Yellow River Basin and Southwestern Cotton Region have a large amount of insects, which is a serious problem. Host plants include cotton, eggplant, potato, beans, cabbage, tobacco, tomato, sweet potato, spinach, pumpkin, mustard, radish, kapok, hibiscus, mallow, sunflower, sesame, mulberry, grape, and citrus.

Injury is characterized by nymphs sucking cotton sap at the back of the leaves. After the leaves are damaged, the tips and edges of the leaves turn yellow and gradually expand toward the middle of the leaves. When the damage is serious, the tips and edges of the leaves turn red from yellow, and later from red to charred black. Finally, the leaves are curled and deformed, and the plants are short and dead. In addition to direct damage to cotton leaf, it also spreads viral diseases.

Morphological characteristics Adult body length is about 3mm. Head, chest yellow-green. The width of the middle crown is approximately equal to the width between the compound eyes; the crown is yellowish green and has two small black dots near the front edge, surrounded by white lines around the black dots. Compound eye dark brown. There are 3 white spots in the front edge of the prosthodontic plate, and 1 white point in the center of the posterior edge. The yellow scutellum is darker, the base of the scutellum base, and each side of the two bases has a white spot. The fore wings are yellowish-green and transparent, and the ends are slightly dark, with a distinct small black spot near the end of the claws. The body's ventral surface includes all yellow, green, green, yellow and green at the end of the tarsal and zygomatic and yellow on the back. In the center of the ventral tail section of the male, each side has a narrow and dense undergrowth lower reproductive plate. The body color of this species varies greatly, and some individuals even have yellowish brown to reddish brown. Egg length 0.7mm, width 0.15mm, long kidney shape. It was colorless and transparent when it was first produced, and gradually turned pale green afterwards. The nymph nymphs were 0.8 mm in length and the mouthparts were as long as the seventh section of the abdomen. There were one milky protruding wing buds on both sides of the middle and back chests. The second instar larvae have a body length of 1.3 mm, mouthparts up to the end of the fifth section of the abdomen, the forewing buds extending to the end of the thorax, and the hindwing buds up to the front of the second section of the abdomen. The third instar larvae have a body length of 1.6 mm, mouthparts up to the first section of the abdomen, front wing buds extending to the end of the first section of the abdomen, and hind wings up to the end of the second abdominal section. The fourth instar larvae have a body length of 1.9 mm, and the mouthpart extends up to the end of the thorax. The anterior wing buds extend to the end of the second abdominal portion, and the hindwing wings extend to the front end of the third abdominal portion. The fifth instar larvae were 2.2 mm in length, with mouthparts extending from the mid-thoracic region, the forewings extending to the fourth abdominal segment, and the posterior wing buds ending at the fourth abdominal segment.

Living habits Nanjing born 8-9 generations, Hubei 12-14 generations, Guangdong 14 generations. Generations overlap. Adults and eggs are overwintered around and within the petioles, tender tips, or veins of eggplant, potatoes, hollyhock, Hibiscus, sycamore, and others. Adults still reproduce on legume crops in winter in Hubei and Guangdong. The period from the middle of May to November is the period of the damage, and the most serious one is from October to November. Adults are active during the day and are particularly active during high temperatures on sunny days. They have phototaxis, are frightened, quickly run or flee. The first and second instar nymphs are often clustered on the base of the leaves near the petiole, adults and third instar nymphs generally feed on the back of the leaves, prefer to eat young leaves, and often climb to the front of the leaves at night or on cloudy days. In the 28-30 °C under the egg period of 5-6 days; nymph period 5.6-6.1 days; adult period 15-20 days. Below 6°C enters hibernation.

Control methods (1) Breeding insect-resistant varieties. (2) timely sowing, rational dense planting, increasing phosphorus and potash fertilizers and organic fertilizers to promote the healthy growth of cotton. (3) Pay attention to the dynamic changes in the number of cotton leafhoppers. When the leaf has been victimized, spray 2% leafhopper powder or 5% Menetide powder every 667m22k8. (4) 25% Phosphorus, malathion, fluoxetine 1000 times or 2.5% Chrysanthemum buttermilk 2000 times, 10% imidacloprid wettable powder 2500 times, 20%虱 Ling EC or 50% octoate phosphate EC 1000 times.