The apple golden moth is mainly harmful to apples, but also to pears, peaches and so on. The insect uses larvae to submerge leaf flesh under the epidermis, forming brown linear insect spots, affecting the photosynthesis of leaves, weakening the tree potential, and when the whole leaf wilts in severe cases, it falls off early, which is one of the key pests of current fruit trees. Let's take a look at its harmful symptoms and prevention methods.
First, the morphological characteristics
Adult insect, body length 2.5 to 3 mm, body golden yellow, silvery-white scales on the top of the head, narrow forewing, three silver-white longitudinal bands at the base, three silver-white claw-like stripes on the anterior margin of the end of the wing, 1 triangular white spot on the posterior margin, narrow hindwing, fine-pointed, gray-brown, and very long margin hairs.
Larvae, body length 6 mm, flat body, triangular head, broad forecoccum, body milky white, translucent, old mature larvae body length, flat head, yellowish white body, long body hair, white.
Eggs, oblate oval, milky white, translucent, later dark brown. Pupae, fusiform, yellow-brown, about 4 mm long, hidden in a white "H" shaped cocoon.
Second, the situation of harm
Larvae from the leaf dorsal epidermis sub-moth into the leaf, eat the leaf flesh, there is black insect feces in the leaf flesh, the affected leaf only has the epidermis, the appearance is a soybean grain-sized vesicle-like, the front of the leaf is raised into a roof ridge, many mesh-like white spots appear, severe each leaf has 10 to 20 insect spots, the whole leaf is wrinkled, the leaves fall early, affecting the nutrient storage of the tree, the fruit is expanded, and the next year's budding and flowering.
Third, the law of occurrence
Occurs 5 generations a year and overwinters in an "H"-shaped white cocoon on the back of the affected leaf. The peak of each generation of adult insects occurs: mid-April in the wintering generation, the first generation from the end of May to early June, the second generation in early July, the third generation in early August, and the fourth generation in mid-to-late September. The second generation of adults overlapped for generations until the end of early October, when the adults never stopped. Adult insects have strong chemotaxis and phototropism, mostly in the morning or evening activities, the amount of moths gradually increased from late June, until the middle of September to reduce the amount of moths. Generally, it occurs lightly in the spring and heavy in the autumn. The eggs are scattered on the back of the young leaves, and the egg stage is 3 to 9 days.
The first generation of larvae is infested in early to mid-May, and it is harmful to 1 to 4 leaves at the base of the new shoots in the lower part of the canopy. The second generation of larvae is infested from late May to early June, and is still dominated by adult leaves in the lower part of the canopy. There has been generational overlap since the third generation. The third generation of damage occurs in early to mid-July, and the amount of damage gradually increases, expanding to the upper part of the canopy. When the damage is severe, leaves begin to fall in late July. The fourth generation of larvae is infested in mid-to-late August, and from mid-September to early October, the fifth generation of larvae have pupated overwintering, and a large number of larvae that cannot pupate cannot overwinter and are frozen to death.
Fourth, the key prevention and control period
Apple golden moth is a larval drilling in the leaf hidden as a pest, the occurrence of algebra in more than five generations, to the later stage of generation overlap, insect state mixed, control period is difficult to grasp, but the first and second generations that occur in the spring of each year are relatively neat, is the key period of annual control.
5. Bug monitoring
Because the adult apple gold-veined moth has chemotaxis, the water bowl trap is made of a core containing exohormonal hormones (the core is hung in the upper part of the trap, the trap is filled with water, and a little washing powder is added), hung on the tree, selected as a seriously harmful park in the calendar year, hangs 1 every 50 meters, before 10 a.m. every day, records the number of lure moths, fishes out the insect carcass, adds enough water, statistically analyzes the peak of adult insect occurrence, and the peak of each generation of adult insects is pushed back for about 7 days, which is the peak of larval occurrence, and immediately issues a larval control forecast.
Sixth, prevention and control methods
1. After the fall of leaves in autumn to before the feathering of early spring of the following year, clean the fallen leaves in the orchard, cut off the inner branches, drooping branches, over-dense branches and germination strips under the canopy, and bury or burn the fallen leaves and the cut branches in a concentrated manner to lower the base of the overwintering pupae.
2. In early April, according to the characteristics of adult insects with chemotaxis, in the feathering period of each generation of adult insects, a water bowl trap is made of sexual attractants, suspended in the canopy, and 5 to 6 traps are suspended every 667 square meters to trap male adult insects.
In mid-April, according to the characteristics of adult insects with phototropism, each generation of adult insects hang fluorescent lamps near the park at night, and place water basins under the lights to trap adult insects.
4, starting from the beginning of May, the first and second generation of larvae occurrence period is relatively neat, is the key period of annual control, according to the insect situation monitoring and forecasting situation, in the larval occurrence period, spray biopesticides (insect regulators) 20% sullicidal suspension agent 5000 times, 25% urea No. 3 suspension agent 2000 times, BT biopesticides, etc., can control young larvae and some adults and eggs, if you miss the young larval stage, you can use 25% of the moth net, 48% Les ben milk oil 1500 times, 25% Cypermethrin 3000 times, 20% saluter 3000 times and other insecticides control of mature larvae and some adults and eggs.
5. Protect natural enemies such as peach bees and ji small bees, and can destroy some insect eggs.