Cotton cotton roots

Scientific name Smynthurodes betae Westwood Homoptera, Aphididae. Alien beans, root pods and beetroot pods. Distributed in North China, Central China, and East China.

Host cotton, beans, beans, sweet peas, potatoes, tobacco, tomatoes, cabbage, turnips, beets, wheat, oats, rye, alfalfa and so on.

The damage characteristics absorb the cotton root sap near the main root of the cotton, causing damage to the lower part of the main root and the fibrous root, or withering, blackening or rot. The darker leaves of the plant darken and fight, the cotton seedlings grow slowly, the cotton stems become red or the top of the leaves wither, and the leaves become thin or wither. In serious cases, cotton seedlings were killed and died.

Morphological characteristics Wingless orphan female egg body oval, 1.8mm long, 1.4mm wide. Milky white or light orange, slightly covered with white wax powder. The body surface is smooth and densely short haired. The frontal tumor is not obvious and is flat-topped. The tentacles are thick, short, smooth, five, and sometimes six. There is a small circle of primary sensory circles in Section 4. There is a large circle of native sensory circles at the base of Section 5. The long taper to the hindfoot base section, section 4-5 is 3 times the base width, and the length is short and thick. Abdominal tube. The tail piece is small, semicircular, with 40 short hairs. The winged female, female and female, is oval in length, 2.1 mm in length and 1.1 mm in width. The tumor is not obvious. The tentacles are 6 knots long and 0.54 mm long, which is 0.26 in length. The third quarter has 7-11 rounds of large and small circular secondary sensory circles arranged in a row; 2-4 in the fourth quarter and 0-1 in the fifth quarter. Minda feet in the base section. The veins and wings of the wing are gray and black, and each vein has gray and black narrow counties. The fore wing diameter can reach the wing tip, the midrib is single, and the hind wings have 2 cubits.

The habits of cotton roots were distributed horizontally in the soil, which was the most from 5cm around the plant, followed by 15cm, and vertical in the 5–10cm soil layer. In fear of light, when light is seen, it is crawled into the earth seam. It is often symbiotic with small yellow ants in the soil, and is relocated or transferred by small yellow ants. Sandy loam, loamy soil, and good permeability are serious risks. Even cropping fields are prone to occur, and the occurrence of high temperatures in early and rainy seasons is also very serious. According to the Shandong survey: from late April to early May, the daily average temperature was 14.4–17.8°C, and the cotton roots originated on May 13 and the latest was May 25.

Prevention methods (1) rotation. (2) Remove weeds from fields and fields. (3) 3% carbofuran granules for seed dressing, 1.25kg per 667m2 of 1.5kg or l5% iron granules, and more than 90% for 50 days. In addition, 10% imidacloprid wettable powder 78 or 3% 1605 granules, 3% monocrotophos granules, and 1.5 kg per 667m2 seed dressing are available, effective for 1 month. (4) Irrigation of roots in the initial stage of cotton seedlings. 50% phoxim EC or 20% methomyl EC 1500 times, 10% imidacloprid WP 1500 times, 50% WP WP 3000 Times of liquid, 40% of monocrotophos EC 2500 times, 40% of methylisotriphos-peroxidase 2000 times, 35% of Sadan EC 1500 times, control effect of 80-90% for 10 days.