For the harm of garden plants of underground pests are diverse, mainly including grubs, ground tigers, caddisflies, golden needle worms, etc., the method of its control can be viewed xiaobian's previous article "Spring, underground pest control is urgent", today Xiaobian mainly explains to you one of the underground pests - ground tiger.
Ground tiger belongs to the insect class Lepidoptera nocturnidae, commonly known as ground silkworms, soil silkworms, is one of the multi-food plant pests, for the damage to crops and garden plants caused by more than 10 species of losses, of which small land tigers, land tigers, yellow land tigers, white edge land tigers and other particularly serious harm. Ground tigers are infested with larvae. The feeding habits of the ground tiger are very mixed, and it not only harms crops, but also endangers garden plants.
Its main hosts and harmful crops are:
Corn, sorghum, wheat, potatoes, legumes, hemp, tobacco, rape, melons and a variety of vegetables, etc., a variety of weeds are also one of the important hosts of the ground tiger. Vegetable seedlings are also often harmed.
Its main hazards to garden plants:
More than 100 kinds of garden plants, such as poplar, willow and cedar, are the most harmful pests of seedlings, flowers, fruit trees and lawns. The light causes the lack of seedlings and ridges, the heavy ones destroy the seeds and replant, and some can climb to the seedlings to bite the young stems and young shoots.
The following figure shows the harm of ground tigers to the lawn:
The following figure shows the harm of ground tigers to cucumber seedlings:
The following Xiaobian conducts a simple analysis of several of the more serious harms of the ground tigers, hoping to bring some help to everyone!
Morphological characteristics:
Adults of small ground tigers are about 20 mm long, have a wingspan of about 50 mm, and have dark gray-brown bodies. The rings, kidney spots, and sword-shaped stripes on the forewing surface are all black and are obviously visible. Both the baseline and the inner horizontal line are wavy black double lines. The hindwings are off-white , the leading edge , apex , and margin line are brown , the wing veins are dark brown , and the outer edge line is blackish brown. The eggs are flattened and round, the surface of the eggs is reticulated, the initial birth is white, and the larvae are grayish brown before hatching. The larvae are about 50 mm long when mature, gray-brown to black-brown, rough on the surface, and densely covered with black grain spots. The dorsal midline is pronounced, and the hip plate is yellowish brown. Pupae brown with 1 pair of ventral and tail-rump spines.
Life Habits:
Small-scale tigers generally occur in three generations per year north of the Yellow River, and four generations occur per year from the south of the Yellow River to the banks of the Yangtze River Basin, and the more they are distributed to the south, the more algebra they are. In the Shanghai area, pupae, mature larvae and adult insects can overwinter in the soil for four generations a year. Adults feather in mid to late March. The first generation of larvae that cause serious harm in production, and the number of subsequent generations has decreased sharply, and the harm is less severe. The first generation of larvae are harmful in mid-April, late to late May, and pupate in late May in soil 1 to 2 inches deep, and adults are phototropic and sensitive to the smell of sugar, vinegar and wine. Most of the eggs are laid on the surface of the soil or on the back of weedy leaves. The first larvae hide in the weeds, eating weeds first, and diving into the soil during the day after the third and fourth instars. Nocturnal excavations are active, suspended to death, and often bite off seedlings are dragged to the mouth of the hole, which is easy to find.
Distribution characteristics:
Areas with moist soils are severely harmed, while arid areas are less harmful. Distributed throughout the country, with heavy rainfall and humid climate in the Yangtze River Basin, it occurs seriously. The northern region is only heavily affected in low temperature, rainy years. There are 6-7 generations a year in Liangguang and Fujian, and 3 generations a year in North China. The infestation periods of larvae in Hebei region occur from May to June, August and September to October, respectively.
Adult yellow-ground tigers are about 18 mm long, have a wingspan of about 42 mm, and are grayish yellowish-brown. The forewings are greyish brown with brown double lines on the wing surface, and the sword pattern is small, with dark brown edges. The ring stripes have black edges and are black-brown spots in the center. The kidney-shaped spots are tan or black. The hindwings are white and translucent, and the veins are clear brown. The larvae are about 40 mm long and earthy yellow when mature. The dorsal midline and valve line are light brown , with yellow-brown spots on the sides of the body , and yellow longitudinal stripes in the center of the hip plate. The pupa is yellowish brown and densely dorsal leading to the fifth to seventh ventral segments.
Yellowland tigers occur in the northern region of Xinjiang for 2 generations a year, in the northeast, north China and northwest China 2-3 generations a year, and in east China and central China 4 generations a year, with pupae and old mature larvae overwintering in the soil. This insect has similar habits to that of small ground tigers.
It occurs severely in areas with dry climates and sparse rainfall.
Hazardous plants:
It is harmful to seedlings of hinoki, pine, willow fir, fir, grass, dahlia, lawn and a variety of flowers and fruit trees. The harm is similar to that of the tiger in the small land.
Adult earth tigers are about 25 mm long, have a wingspan of about 50 mm, and have a dark brown body. The forewings are greyish brown with a black leading edge and black stripes on the wing surface, with pronounced rings and kidney-shaped spots, with black edges. The hindwings are dark brown with a darker outer margin line. The ovoid is semicircular and pale yellow. The larvae are about 56 mm long and yellowish brown when mature. Flat cylindrical, wrinkled body surface, inconspicuous dorsal line, dark brown hip plate.
Earth tigers occur in one generation a year and overwinter as 3-year-old larvae lurking in the topsoil layer and overgrowing in the weeds. In March of the following year, the overwintering larvae begin to move, hiding in the shade during the day and feeding on the rhizomes of the seedlings at night, causing a large number of seedlings to die. From May to June, the old mature larvae begin to sleep, and after the summer sleep, they pupate in the soil chamber, and the pupal period is about 30 days. In mid-to-late October, adult insects feather, adult insects lurk among dead leaves or weeds during the day, nocturnal activities, sugar, vinegar, liquor has a tendency, and phototropism is not strong. Spawning occurs on leaves in or near the ground in the soil layer, with an egg stage of about 12 days. The larvae are 7 years old. Pupates pupate in early and mid-September and feathering from late October to early November. The eggs are scattered on weeds or soil masses, and soon after autumn, as the temperature changes, the young larvae overwinter in the soil. Its larvae are highly resistant to cold.
Among them, the earth tiger is more similar to the small ground tiger, and we can distinguish it according to the following figure:
(1) Eliminate the source of insects.
Weeds are the feeding material for the laying grounds of ground tigers and young larvae, and the removal of weeds and debris can greatly reduce the density of insect populations. If eggs have been laid and 1-2 year old larvae are found, they should be sprayed first and then weeded to avoid individual larvae from hiding in the soil. Remove weeds, stay away from the seedling area, and dispose of it with manure.
(2) Tung leaf booby trap method
Ground tiger larvae have a tendency to paulownia leaves, can take the older paulownia leaves, soaked with water, placed in the field in the evening, put 80-120 pieces per acre, the next morning to open the leaves, catch the larvae, the effect is very good. If the paulownia leaves are first soaked in 150 times the liquid of 90% crystalline dimethods, and then put into the field, the ground tiger larvae can be directly killed, and the medicinal effect can last for about 7 days.
(3) Poison bait booby trap method
Take 90% crystal enemy insect 1 kg, first dissolve with a small amount of hot water, then add 10 kg of water, evenly spray on 100 kg of fried cake flour or wheat bran, mix well and sprinkle it on the root of the crop in the evening, use about 5 kg per mu, and the tiger control effect is very good.
(4) Sweet and sour liquid booby trap method
Preparation method of sweet and sour liquid: 6 parts of sugar, 3 parts of vinegar, 1 part of white wine, 10 parts of water, 1 part of 50% diazine phosphorus mixed well, and booby-trapped during the adult occurrence period. Some fermented and sour foods, such as sweet potatoes, carrots, rotten fruits, etc., can also be booby-trapped to kill adult insects.
(5) Artificial capture method
Taking advantage of the habit of the earth tiger to lie down at night, in the early morning on the ground around the murdered crops, use a small shovel or a small wooden stick to dig out the ground tiger to kill.
(6) Irrigation and flooding method
For nurseries that can be irrigated for a short time, when a large number of ground tigers occur, the nursery is flooded for 1-2 days, which can drown most of the ground tigers, or force them to flee and manually hunt and kill.
(7) Black light booby trap method
Adult ground tigers have a strong phototropism, with sweet and sour liquid and black light, used in clear, breezy, moonless nights, can receive a good booby trap effect. Putting a basin of water in a black light lamp, putting pesticides in the water, or pouring a layer of waste motor oil also has a good killing effect.
(8) Hoeing and egg extermination method
In the field tiger spawning to the peak of hatching, timely hoeing and ploughing, can greatly reduce the hatching rate of eggs.
(9) Grass trap method
After 3 years of age, the resistance of ground tiger larvae increases, and it is difficult for ground spraying to receive the expected effect. Can be trapped by the grass pile method, that is, in the evening, the fresh grass is evenly stacked in the field, 80-100 piles per acre, each pile area is 0.1 square meters, the next morning open the grass pile, hunt the larvae, for 5-7 consecutive days, you can kill most of the larvae, the grass pile is generally replaced every 3-4 days, and a little water can be splashed after the sun dries up to improve the trapping effect.
(10) Chemical control.
The 1-3 year old larval stage of the ground tiger has poor resistance and is exposed to the host plant or the ground, which is the appropriate period for drug control.
Sprinkle poisonous soil:
Use "Ground Worm Qing" to mix fine sand and spread evenly, and then irrigate with water to make the liquid penetrate the soil fully. Since the larvae of the ground tiger are more active than in the evening, the application time is best chosen in the evening, and the effect is the best.
spray:
In the 1-3 instar larval stage of the ground tiger, the surface spray was carried out by 50% diazinphos emulsion 2000 times liquid and 20% cypermethrin emulsion 1500 times liquid. The 3-instar larvae are pre-clustered on weeds and seedlings, and the resistance to drugs is low, which is a critical period for drug control.
(11) Biological control:
Protect and utilize predators such as insectivorous birds, walking insects, toads, cocoon bees, bees, parasitic flies and fungi.
Here we need to pay attention to the following issues:
First, the prevention and control of larvae No matter which control method, it is best to use medicine in the evening.
Second, among these kinds of land tigers, the harm of small land tigers is the most serious.
Third, the 1-3 year old larval stage of the ground tiger has poor resistance and is exposed to the host plant or the ground, which is the appropriate period for drug control.