In the hot and rainy season, the young shoots and young leaves that have just been extracted are easily infected with diseases and insect pests, such as the leafminer moth has long been unable to hold back, and it is going to come out to harm the autumn shoots of fruit trees. Leafminer moths not only harm young leaves, but also increase the risk of infection due to leaf damage, such as canker disease, anthrax, etc. It is important to pay attention to the prevention of citrus leafminer moths to ensure that the autumn is slightly stronger and lays the foundation for a good harvest in the coming year.
1. Citrus leafminer moth
Citrus leafminer moth, also known as drawing insects, ghost drawings, leafminers, etc., belongs to the Lepidoptera leafminer moth family, is the main pest that harms the new shoots of citrus, and the most seriously affected are the summer and autumn shoots. Its harm rate is high and it is a great threat to citrus production.
Adults are small, silvery-white moths with a body length of about 2 mm and a wingspan of about 5 mm. The forewings are lanceolate , with two brown longitudinal stripes at the base of the wings , about half the length of the wing , with " Y" black stripes in the middle of the wings. The tip of the wing has a black round spot. The hindwings are coniferous. The margins are very long. The larvae are 4 mm long, spindle-shaped, flattened, yellow-green.
Leafminer moth adults and larvae
Second, the harm of leafminer moths
It mainly harms citrus shoots and young leaves, and there are also a few victims of the fruit. Its larvae sneak under the epidermis to feed, causing many silver-gray tortuous insect tracts, making the leaves curl, harden, easy to fall off, and the new growth is not full, which seriously affects the photosynthesis of the leaves, the growth of fruit trees and the flowering and fruiting of the next year. The fruit is susceptible to decay, which directly affects the inside and outside of the fruit. The curly leaves caused by the damage are often the wintering places of pests such as red spiders and leaf curl moths.
The damage of citrus leafminer moths to the wounds caused by leaves and branches is more likely to lead to the invasion of citrus canker bacteria, which seriously affects tree potential and yield.
Third, the occurrence of leafminer moths
The citrus leafminer moth began to be harmful from the summer shoots in early June, and continued until the autumn shoots ripened in early October, and the most harmful from July to September, which was also the most abundant and critical period for the extraction. Adult citrus leafminer moths are phototropic and tend to inhabit the inner leaf back of the canopy and in the weeds of citrus orchards during the day, and are active frequently in the morning and at 8-10 pm. Female moths lay eggs on both sides of the midrib of young leaves or on young branches, the larvae hatch into the leaf or young shoot epidermis hazard, the larva endangers the young leaves, young branches, so that the leaves are hard and brittle and fall off, the growth of new shoots is hindered, affecting the tree potential and shoots.
High temperature and rain are conducive to the occurrence of harm to the insect, the occurrence of citrus leafminer moth is closely related to nutritional conditions, due to the scattered summer shoots of citrus trees, rich food, coupled with summer and autumn high temperature and humidity suitable for its reproduction, so it is often rampant in summer and autumn.
Fourth, the occurrence characteristics of leaf-diving moths, control difficulties
1. Mainly occurs in the young shoot stage after summer and autumn shoots, adult eggs lay on the young combination weaving (leaves, young shoots), and the larvae drill on the young leaves and young rods, and also drill the skin of the young fruit.
2, the prevention and control can not be sprayed in time for prevention and control, farmers often find that there is harm before using drugs, it is more difficult to control the damage caused to the leaves. In particular, the newly planted young trees are not medicated in time, which affects the growth of saplings. At the same time, because of its wounds, it is easy to cause ulcer disease.
3. Do not wipe the shoots and control the shoots, allow the branches to grow freely, there are many varieties of citrus, overgrown weeds, close to citrus nurseries, young tree citrus orchards, etc. are more prone to leafminer moth infestation.
5. Integrated control programme for leafminer moths
From January to September, control the summer shoots, concentrate on the autumn shoots, worsen the feeding conditions of the citrus leafminer moth larvae, break their food chain, and reduce the source of insects and the number of sprays, which is the fundamental measure to control the citrus leafminer moth.
2. It is strictly forbidden to use highly toxic pesticides, try to avoid the use of organophosphorus pesticides, and protect and utilize natural enemies. The natural enemies of leafminer moths include a variety of parasitic bees such as the White Star Ji wasp, grasshoppers, predatory ants and Bacillus thuringiensis.
3. Rational weeding to reduce the activity site of leafminer moths. If the grass is left to retain water, one is to pay attention to the weeds can not be too high, and the other is to spray the weeds on the edge of the plant when spraying during the high incidence period of the leafminer moth from July to September.
4. Choose the right pharmacy for prevention. Since leafminer moths mostly inhabit the inner leaf back of the canopy and the weeds of citrus orchards during the day, and are frequently active in the morning and at 8-10 pm, it is necessary to choose a good agent with systemic and gastric toxicity and kill Lepidoptera for prevention and control. It can be sprayed in the summer and autumn when the shoots are 0.6 to 2 cm long, sprayed once every 7 to 10 days, and sprayed 2 to 3 times continuously to protect the growth of new shoots.
The above content is from the network and is for reference only.