Mung bean pest: wild bean borer

(1) Harm condition also known as cowpea pod borer, pod wild borer, cowpea borer. It is widely distributed in China and occurs seriously south of the Yangtze River. Larvae eat host flower organs, resulting in flower drop; eat pod, early cause pod drop, late cause pod and seed rot. In addition, it can also spin silk to wrap several leaves together, larvae eat mesophyll in it; or eat tender stems, causing withered shoots, which has a great impact on yield and quality. (2) Morphological characteristics: adult 13 mm long, wings 24~26 mm, dark yellow brown, two white transparent spots in the center of front wing, white translucent after wing, dark brown ripples inside. The eggs are flat oval, pale green, with hexagonal reticulation. The mature larvae are 18 mm long, brown in head and chest, and yellowish green in body. The pupa is 13 mm long and yellowish brown. (3) The number of generations of living habits varies from place to place in a year. The adults are active from 21:00 to 1:00 midnight. They have phototaxis. Bean borer is a warm-loving pest, especially in southern China. For example, in North China, it can have 3~4 generations a year and overwinter as pupae; in South China, it can overwinter as larvae or no obvious overwinter phenomenon. Generally, the peak period of this pest is from June to July to September to October every year. (4) Control methods ① Remove the fallen flowers and pods in time, and remove the injured leaves and pods to reduce the source of insects. (2) Set up black lights in the field to trap adults. (3) Spraying pesticides, such as 800 times solution of 50% dichlorvos emulsifiable concentrate, 3000 times solution of 25% Jule mixture, or 3000~4000 times solution of 10% pesticide, 2.5% deltamethrin, 10% cypermethrin, etc. From budding, spray buds and flowers once every 10 days.