In autumn, in addition to underground pests in the lawn, leaf-eating pests have also entered the peak of harm. In particular, several common "nocturnal moth" pests often come out to "demonize", and their forms are complex and changeable, and once the damage breaks out, it will add a lot of difficulty to the garden maintenance work.
How should these "moths" be distinguished and controlled?
01. Light sword nocturnal moth
1. Identify features
Adult: The inner and middle transverse lines of the forewings are black with a nearly trapezoidal dark brown spot on the wing surface.
Larvae: large changes in body color, gray-brown at the beginning of hatching, reddish-brown head, green after feeding. The larvae are cylindrical in shape, with a figure-of-eight stripe on the head and a nearly half-moon or triangular black spot on the inner segment of the sub-dorsal line. It is suspended dead, and the shock curls in a "C" shape.
2. Hazard characteristics
At 1 to 2 years of age, the larvae feed on the tender leaf flesh, leaving a transparent leaf epidermis. After the age of 3, the leaves are eaten, eaten into missing carvings, and the young stems are nibbled on the stems of the lawn. After entering the 5 to 6 years of age, the amount of food increased greatly, for the binge eating period, the leaf veins and young stems were eaten, the damage of biting day and night on rainy days and nights, the light caused by yellowing of the lawn, if not prevented in time, it would cause the entire lawn to die when it was serious, which greatly affected the landscape effect.
3. Occurrence of regularity
It occurs for 4 to 5 generations every year, and the old mature larvae overwinter in lawns, weeds, etc., and there are pests from May to October. Generally from July to September every year, the 3rd and 4th generations of larvae occur in large quantities, high temperature, dryness and lawn are sufficient to facilitate their growth and reproduction, when the environmental conditions are conducive to their normal development and reproduction, it is very easy to erupt on the lawn.
02. Twill nocturnal moth
Adult: The inner and outer transverse lines of the forewings are white, wavy, and there are obvious white oblique broad bands in the middle, so they are called twill nocturnal moths.
Larvae: The thorax is variable, ranging from earthy yellow to black-green, with less obvious white spots on the surface of the body. The old mature larvae have a dark brown head, no figure-of-eight pattern, and the dorsal dorsal area has a nearly half-moon or triangular black spot in each segment of the sub-dorsal line, of which the first and eighth abdominal segments have nearly rectangular black spots.
2. Hazard characteristics
Twill nocturnal moth is an omnivorous pest, mainly larvae, with fulminant, insect population density, can eat the lawn into a "light stalk" in a short period of time. When the damage is mild, it will cause the lawn to turn yellow, and if it is not controlled in time, it will cause the entire lawn to die (a large amount of insect feces can be seen under the grass, according to which larvae can be found at the rhizosphere), bringing devastating damage.
3. Occurrence of regularity
Twill moths occur in 4 to 5 generations a year, and the hazard peak period is from July to September, which is also the warmest season of the year. The adults emerge diurnally and nocturnally, during the day on the underside of the leaves or in the soil, and are active from late afternoon to early the next morning, feeding on lawn leaves. The hatching larvae of the twill moth are clustered and are a critical period for control.
03. Grassland nightcrawler
Adults: Dark brown forewings, grayish-white hindwings, with narrow brown bands at the edges. There is a yellow irregular ring in the middle of the forewing, followed by a kidney-like stripe.
Larvae: Generally have 6 ages, the body color is light yellow, light green, brown and other, the most typical identification feature is that there are 4 black dots arranged in a square arrangement on the back of the terminal ventral segment, and the head can be seen after three instars.
Grassland night moth, also known as autumn armyworm, will appear translucent film "window holes" and irregular long holes when harming plant leaves, and can also eat the entire leaves of the plant, which will cause large-scale death of the plant when severe. Sometimes a large number of larvae harm by cutting roots, cutting off the stems of seedlings and young plants, causing serious losses. When the population is large, the larvae are like marching and spread in groups.
The grassland moth has a strong reproductive ability, can reproduce several generations a year, and has a strong ability to migrate over long distances, and can quickly spread from one area to another larger range. The rapid spread rate, coupled with the heavy harm of overeating, is often difficult to prevent and control.
Chemical control points
Since larvae are the main harmful stage of "nocturnal moth" pests, it is necessary to seize the best prevention and control period in garden maintenance, adhere to the policy of "early treatment, small treatment, early detection, early prevention and control", and carry out pharmaceutical control in the early stage of larval hatching.
1. At the beginning of the occurrence, it is recommended to use 5% high chlorine and methyl vitamin salt microemulsion (Qilin Royal Moth) 800 to 1000 times liquid for uniform spray control. To avoid drug resistance, rotation with 22% thiamethia and perchlorofluoride microcapsulant suspension-suspension (Kirin Guangzheng) is recommended.
2. When severe occurs, the drug resistance of the larvae after 3 years of age is significantly enhanced, combined with the work experience of grass-roots plant protection, it is recommended to use 14% avie mite nitrile suspension agent (Qilin Yindi) 600 to 800 times liquid uniform spray control, can achieve a good control effect. To avoid drug resistance, rotation with 16% mevin indinavirus-suspension (Guangcan) is recommended.
Source: China Flower News