What kind of insects are these on walnut leaves, and how to prevent and remove them?

It should be the first instar larva of the American white moth. The larvae of the American white moth are characterized by a large population density, concentration, and outbreak hazards, and one of the identifying characteristics is that they have obvious net curtains, and larger insects will disperse the damage. In our country, 2-3 generations occur a year, and dangerous quarantine pests introduced into the United States occur.

Almost all agricultural pesticides will be effective, and it is recommended to use a low-toxicity pesticide based on pyrethrin or a matrine bioinsecticide. Juvenile and egg stage can also be killed with larvaluride, no residue, no pollution.

You're probably talking about walnut leaf beetles.

The insect mainly harms walnut branches and leaves, and is one of the main pests of walnut leaves. Adults and larvae feed on the mesophyll, and the harmful form is reticulated or missing, and sometimes the whole leaf is eaten up, leaving only the leaf veins. The insect occurs in one generation a year, and the adult overwinters in the ground cover or in the crevice of the skin at the base of the trunk.

In early to mid-April of the following year, the overwintering adults begin to be active, and often flock on the leaves to feed on the harm. From late April to early May, eggs are laid on the back of the leaves in lumps, with about 20-30 eggs per piece. The larvae hatched in mid-May, and the first hatched larvae fed in clusters, and the infested leaves were yellow, and dispersed to the whole tree after the second instar.

In late May, the tail end of the mature larvae adheres to the back of the leaf, peels off and pupates, and the end of the belly of the pupa adheres to the molt of the larva, hangs upside down on the back of the leaf, and can bend and stretch when touched. The pupal stage is 4-5 days, and the adult worm emerges, and after a short period of feeding, it is under the tree, and it is dormant for wintering. May to June is the peak period for overwintering adults and larvae to appear at the same time, when the big occurrence, the whole leaves of the tree are eaten up, like fire.

Damage for 2-3 consecutive years will cause the whole plant to die.

The control method is to combine the control of walnut fruit elephants in late April and early May, and spray with walnut Baoguolin diluted 800-1000 times; During the period when adults occur in large numbers, they are trapped by a pile of fire or a black light. Using its habit of feigning death, it is artificially shocked and killed.

Spider mites, caterpillars, which are more common insects, can be sprayed with pesticides, can be sprayed dimethoate, imidacloprid, can also be solved in some other ways, but also through some physical solutions.

The insects on the walnut tree include the larvae of the stinging moth, the beetle, the beetle, the silkworm moth, and the walnut yellow thorn moth. You can apply some pesticides, you can spray some pesticides, and you can also sprinkle some insecticides.

There will be yellow thorn moth on walnut trees, and if this insect pest appears, you can choose to use insecticides**, you can choose cypermethrin insecticides, and then spray them according to the instructions. Then red spiders will also appear on walnut trees, and what is needed is a bufludilate insecticide. Walnut trees will also appear raised limb moths, which need to be sprayed with thiophos emulsifiable concentrate for control.

If the walnut tree is infected with the stinging moth, you can spray the dichlorvos emulsifiable concentrate solution to avoid touching the stinging moth with your hands, which will cause allergies. After being infested by the yellow-green stripe borer, pyridazine thiophos emulsifiable concentrate solution can be sprayed. After being attacked by scale insects, dimethoate solvent can be injected into the bark.

Prune the wilted branches and leaves of walnut trees in time to enhance air circulation and reduce the breeding of bacteria and insect pests.

If a walnut tree is infected with a stinging moth, it will cause the leaves to gradually turn yellow and fall off. It is necessary to remove the eggs around the trunk. Dichlorvos EC and phosphine EC solution were diluted and sprayed on the damaged part of the walnut tree.

Stinging moths are poisonous, do not touch them easily with your hands, they will cause redness, swelling and pain, you can apply baking soda on **.

Walnut trees infected with yellow-green stripe borer, will quickly erode the leaves, absorb the water in the leaves, resulting in the withering and death of the leaves, can be diluted pyridazine thiophos emulsifiable solution, sprayed on the pest site for effective prevention and control, to ensure the circulation of ambient air, can promote the recovery of walnut trees.

Walnut trees are suffering from scale insects, which cause yellowing of leaves, and if the foci is severe, it will erode the branches of walnut trees. You can use a knife to peel off a small hole in the bark of the walnut imitation tree, and inject dimethoate solvent into the bark. Spraying insecticides directly on the trunk in spring, summer and autumn can be well controlled from top to bottom.

Walnut trees grow rapidly and have dense branches and leaves, so it is necessary to prune the wilted and old yellow branches and leaves in time to reduce the consumption of excess nutrients. Carry out thinning to reduce the growth of bacteria and insect pests. Improving the growth space circulation of walnut trees, ensuring sufficient light, and timely supplementing water and fertilizer can improve the disease resistance of walnut trees.

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Problem description: How to solve the insect infestation on the walnut tree? It's the yellow one!

Analysis: Control methods of walnut tree insect pests.

Sugar scales are infested by nymphs fixed on branches to suck the sap of trees, and the population density of insects is the highest on 1 to 3-year-old branches. It weakens the tree and causes the branches to dry up and die.

Control methods The effective drug control period of sugar scale is the activity period of nymphs, that is, from the end of May to the beginning of June and the beginning of September. It can be sprayed with 50% insecticidal pine EC or 20% Puwei EC and 25% insecticide 500 times to 800 times liquid, and the effect is good.

Leaf mite is also known as yellow spider. The larvae, nymphs and adults of P. limphylla all harm walnut leaves. The affected leaves appear pale yellow at first, and then gradually turn to brownish-yellow or tan in hail, and in severe cases, the leaves are scorched and fall off. All the main walnut producing areas in Xinjiang are harmed by P. pruna.

Control method In late March, the whole garden (tree) was sprayed with 5 Baumé stone sulfur mixture or 45% Solibar powder 70 times. From the end of April to the end of May, spray 1500 times to 2000 times of 5% Nisolan EC or 4000 times of 50% Apollo suspension. From July to August, spraying zidicin series biological insecticides for control.

In winter, the sails are cleared of weeds, the garden is cleared, the bark is scraped, and the whitening is brushed.

Bacterial black spot disease, walnut anthracnose, ginkgo biloba silkworm moth, etc., should be regularly applied and management should be strengthened.

Black spot, root rot, these are relatively common insect pests, we must pay attention to the use of pesticides, pay attention to the cleaning of weeds.

For example, giddings, lift-limb moths, wood-leaved inchworms, cloud-spotted longhorn beetles, and parameciums can be controlled with chemical agents, and the problematic parts should also be removed.

It's a scarab. There are many species of beetles, such as black velvet gill beetle, apple hairy beetle, etc., the color and body shape are very different, but most of them have fake death, strong flight ability, adults harm leaf fruits, and larvae are grubs, which harm the root system. Therefore, the control of beetles should be taken comprehensive control, the roots of walnut trees without fruit and the intercrops allowed by the pesticide instructions can be used to eliminate the larvae with the root application of "aldicarb"; Adults can be sprayed with organophosphorus plus pyrethroid insecticides; Black light booby traps are both environmentally friendly and effective.

Pesticides should be used in strict accordance with the instructions for use and take into account food safety. Fortunately, the serious stage of the occurrence of beetle adults is generally in spring, and the time from the ripening of walnuts is relatively long, but it is still necessary to use low-toxicity pesticides and physical methods to prevent and control them.