Cotton tip

Scientific name Phytoscaphus gossypii Chao belongs to the order Coleoptera. Alias ​​cotton weevils, cotton small gray elephant. Distributed in the Yellow River, the Yangtze River Basin, the northwest inland, northeastern provinces and regions.

In addition to harming cotton, the host also damages 33 families and 85 species of plants such as eggplant, beans, corn, sweet potato, millet, hemp, peach, sorghum, wheat, rice, peanuts, pasture, and poplar.

Injury characteristics: Adult insects damage leaves or holes, and sometimes bite off tender tips.

Morphological characteristics adult body length 4.1-5. Omm, females are more hypertrophic, males are smaller and smaller, body and coleopter wings are brownish brown, brown irregularly clouded spots on the eel wings, yellow and green on both sides of the body, ventral surface, metallic luster, twice as long as the width, and tentacles bent Knee-shaped. The thoracodorsal plate is nearly trapezoidal, with 3 brown vertical lines, and 1 punctiform protrusion on the inside of the leg. The egg is about 0.7mm long, oval and shiny. Larvae body length 4-6mm, the head, the thoracodorsal plate is tan, yellowish-white, the back of the worm body is slightly fine, the distal segment has a tubular bulge, and 5 ossification flaps surround the anus and are slightly smaller on both sides. Between the flaps, there are 1 bristle and the middle two bristle lengths. Naked lice are 4-5mm long and the abdomen ends with 2 tails. (right)

Habits of life generation, mostly larvae wintering in soybean, corn root soil. The depth of larvae from topsoil is 25–50cm in the Yellow River Basin and 10–20cm in the Yangtze River Basin. In April and May, the temperature rose, and the larvae rose to the topsoil. In the late May to the end of June, the Yellow River phlegm occurred. In early June, adults emerged, and from mid-June to mid-July, they entered the period of destruction. In the middle of May, the Yangtze River valley was turned into a lake, eight days in the flood season, and adults emerged in the middle and late May. After adult emergence, mating is performed for more than 10 days, and 2-4 days later, eggs are laid. Adults live for about 30 days. Eggs are spawned on the surface of the stem sections or roots of grass crops or under the aerial roots, soil surface, and soil blocks. About 8 days later, the larvae enter the soil after hatching, eating roots, falling temperatures at the end of autumn, and larvae moving over the winter. Adults like to cluster, have a feign death, night damage. The amount of pre-maize corn was high and the victim was heavy.

Prevention methods (1) Occurrence of a large number of areas or fields, the adult excavation period dug a pit of 10cm deep in the field, sprinkle poisonous soil in the pit, cover the grass above, and then concentrate and kill again in the early morning. (2) The use of cotton tip animation can be manually captured and concentrated. (3) When there are 30 to 50 hundred insects in the field or 100 insects in the cotton budding stage and 200 insects in 100 bolls, spray 50% phoxim or 95% Dan emulsion oil 1500 times, 50% methyl 1605 emulsion 1000 times, 40% acephate in a ratio of 1:150 dubbed toxic soil, can also use 1% methyl 1605 powder 1:30 ratio of toxic soil, each 667m broken poisonous soil 30kg.