What causes spinach leaf miners? What are the most effective prevention and control methods?

Spinach is a simple vegetable that many people choose to grow and can even prepare their own potted plants every day. But spinach seed germination has always been a difficult problem to solve. If many people find that the spinach seeds they grow have a low germination rate, what can they do to improve?

In the process of growing spinach, the most inevitable thing is the occurrence of pests and diseases. Among them, broad beans have a great impact on the growth of spinach in the process of growing spinach. Seeds are chosen first.

Newly harvested seeds will have a dormant period for a period of time. At this time, the germination rate is low, and the previous seeds can be used. It is best to remove sunburned, broken, and flattened seeds in time.

These are basically substandard, then rub the seeds properly and repeat gently a few times. Then put it in the sun for a while, sterilize it with sunlight, and then prepare to wake up again.

The seeds begin to wake up after the previous treatment, which determines the subsequent germination rate, so be cautious. First, soak the seeds for 10 to 12 hours or so, then place them in a cool place to observe the cracking of the husk of the seeds. This observation time is about 3-7 days.

Keep the seeds moist during this time, so water them regularly, and if the water evaporates too quickly, it's best to add mulch on top of the seeds to keep the seeds moist. If the seeds show signs of breaking, they should be placed in the soil to take root and sprout. The most important thing here is temperature regulation.

If the spinach sprouts easily, keep the temperature in a range suitable for the growth of the spinach. The optimal temperature for freshly soiled spinach seeds is around 20 22, with a maximum of 25 and a minimum of no more than 15, and it is easiest to germinate at this temperature stage. In the summer, choose a place where the saplings are in the shade, and in the winter, choose a place where the temperature is high and there is no wind.

Temperature affects the germination rate, and moisture directly affects whether spinach germinates. At this time, the amount of watering should be controlled. Because spinach seeds have just sprouted, the roots are not well developed, and too much moisture can lead to dead saplings.

When watering, you only need to drench the surface layer about 2 3 cm, the bottom can not accumulate water, touch the whole soil to feel a certain moist feeling, spinach is most likely to sprout. The main hazard of the spinach leaf miner is that the larvae of the spinach leaf miner collect the mesophyll from inside the leaves, forming wide tunnels. The damage slightly affected the quality, the value of the goods was lost, the losses were severe, leading to the pre-war extinction, and the losses were very large.

The spinach leaf miner flies hatch more than at night, and the larvae can not find the leaves to burrow the borers, and when the environment is suitable, they can burrow the mesophyll for a day, but when they cannot find a host, they can obtain food from feces or humus to complete their development. The larvae have matured for a long time, and some of them enter the mesophyll to pupate, and some of them to pupate into mud. The larvae of the overwintering generation enter the mud pupae, and the pupae are 6 months long.

The spinach leaf miner fly hatches mainly from eggs in the soil. If you want to prevent it, you can start from the following aspects: 1. Turn the soil deep in time to reduce the source of insects in the soil 2. You can sprinkle well-rotted organic fertilizer as base fertilizer 3. Spray drugs during the peak oviposition period of leaf miner flies.

Spinach leaf miner fly, also known as beet leaf miner fly, quinoa fly, has a wide distribution range, and the local area is more serious, it is a serious insect pest that occurs during the growth of spinach, and the larvae sneak under the epidermis of the host leaves, zigzag through, feed on green tissues, and cause irregular gray-white linear tunnels. When the damage is severe, almost all the leaf tissues are damaged, and the leaves are covered with cavities, especially the leaves at the base of the plant are the most damaged, and even wilt and die. Harvest the root stubble early and overwinter spinach, and be sure to harvest all the spinach before the rain in the valley to reduce the oviposition of the overwintering adult generation.

Deep ploughing of the land After harvesting, it is necessary to plough the land in time, which is not only conducive to the growth of plants, but also can destroy a part of the pupa that enters the soil and pupates, which can reduce the source of insects in the field. Applying plantar fertilizer requires the application of fully decomposed organic fertilizer, especially manure, so as not to bring insect sources into the field.

The most inevitable is the occurrence of pests and diseases. Among them, broad beans have a great impact on the growth of spinach in the process of planting spinach. Seeds should be selected first.

Newly harvested seeds will have a dormant period. At this point, the germination rate is low, and the previous seeds can be used. Tanned, broken, flattened seeds should be removed in a timely manner.

Spinach leaf miner flies like to survive in an environment with low temperature and high humidity, there are agricultural control methods and pesticide control methods, agricultural control methods are more cumbersome, divided into three steps, the first step, early harvest, the second step, deep ploughing of the land, the third step, the application of foot fertilizer.

Adult leaf miners are mostly active during the day on sunny days, feeding on nectar or leaf sap and laying eggs. Late March to late May is the most common occurrence. The nectar source was abundant at the flowering stage of rape, the number of adults laid a large number of eggs, the number of larvae at the horn-setting stage increased sharply, and the number of larvae and the degree of damage reached the highest peak at the stage of horn fruit expansion.

In the flowering and horn-setting stage of rapeseed, the larvae sneak into the upper and lower epidermis of the leaves to feed on the leaf beams, forming gray-white curved and irregular insect passages on the leaves, with fine insect feces inside. When the damage is serious, the high bucket on the leaf is covered with insect paths, and the tissue loses its green color, which seriously affects photosynthesis. The larvae also eat young stems, peduncles and young horns.

Prevention and control methods: spray pesticides in the peak stage of adult worms or larvae in the initial hatching period in spring, you can choose 2000 times of 48% chlorpyrifos EC, or 2000 times of avermectin EC, or 2000 times of 5% fluoroqi residue mill urea emulsifiable concentrate, etc., spraying 40-50 kg per mu.

The spinach leaf miner fly Pegomya Exilis (Meigen) belongs to the family Diptera, commonly known as the quinoa spring fly. It is distributed in the northern region of our country. The host plants are mainly spinach, turnips, and beets.

The pest larvae sneak into the leaves to feed on the mesophyll, leaving the upper and lower epidermis translucent, with wide tunnels and insect feces. Generally, there are 1 or 2 larvae in the leaf end, which can affect the yield and quality of vegetables, and can destroy the whole field when it occurs severely.

Morphological characteristics. Adult body length 5 6 mm. The interfrontal part of the male is narrower than that of the anterior monocular, with no frontal bristles, and no bristles under the axillary flap. There are hairs underneath the anterior veins.

The leg and tibia are yellowish-gray, the tarsal joints are black, and the hind foot tibial joints have 3 hind bristles. The length of the posterior branches of the lateral caudal lobe is nearly equal to the length of the anal caudal lobe. The anal caudal lobe is pointed at the end, and the lateral caudal lobe has very pointed and thin claws at the lateral end of the lateral crow branch.

The eighth web of the female fly is small, and its length is less than 1 3 of the seventh web plate, which bears short, dense hairs. The oval is spherical, white, with irregular hexagonal reticulations on the surface. The mature larvae are millimeters long, yellowish, maggot-shaped, with many wrinkles, and have 7 pairs of fleshy protrusions at the posterior end of the abdomen around the posterior valve.

The pupae are about 5 mm long, oval, pale yellowish-brown at the beginning of pupation, reddish-brown later, and blackish-brown before emergence.

Characteristics of occurrence. North China occurs 3 to 4 generations per year. Wintering in the soil with pupa. The first generation occurs on root spinach, the second generation begins in early May, and the third generation occurs in June.

Adult emergences are concentrated in the early morning when the temperature is low and the humidity is high. The pre-spawning period is about 4 days. The eggs are laid on the dorsal surface of the host leaf, and 4 5 eggs are arranged in a fan pattern, and each female can lay 40 100 eggs.

The egg period is 2 to 6 days, more than evening hatching, and then dives into the mesophyll. The larvae have a total of 3 instars. The development duration of each age was 1 day, 2 days and 7 days.

That is, the larval duration is 10 days, and it can reach 20 days in colder areas. Mature larvae can pupate in the leaves, or they can pupate from the leaves to a depth of 5 cm into the soil. Pupal stage 2-3 weeks.

The larvae of the overwintering generation are all pupated in the soil, and the pupal stage is more than half a year. When there is no suitable host, development can be done on manure or decaying organic matter.

Since some pupae of spinach leaf miner flies enter the diapause state in each generation, they emerge at the same time in spring. Therefore, the occurrence of the first generation in the spring of each year is large, and the insect population reaches its peak. The high temperature and drought in summer are not conducive to the activity of adults and the development of various insect states, which can greatly reduce the overwintering insect population and reduce the damage of the first generation in the spring of the next year.

Prevention and control methods. 1) Apply well-decomposed manure.

2) Pharmaceutical prevention and control. Seize the peak of spawning to the early stage of egg hatching. Due to the short growth period of spinach, it is necessary to choose a drug with a short residual effect, easy hydrolysis and photolysis.

You can use 10% chrysanthemum horse emulsifiable concentrate 1500 times liquid or deltamethrin 3000 times liquid, 20% fenvalerate 3000 times liquid, kill (21% synergistic cyano-horse emulsifiable concentrate) 8000 times liquid, 50% phoxanthion emulsifiable concentrate 1000 times liquid, or choose biological pesticides such as afordin emulsifiable concentrate 3000 4000 times liquid.

Spinach leaf miner: Spinach leaf miner is a genus of the order Diptera, the flower fly family, also known as leaf maggots. It is mainly harmful to spinach, beets and other quinoa and knotweed plants.

Pest characteristics: the larvae feed on the mesophyll in the leaves, leaving only the upper and lower epidermis, forming a lumpy tunnel and leaving feces, so that spinach loses its commercial value and edible value.

Morphological characteristics: Adult: body length 4.6 mm, thorax dorsal grey-yellow or green, tarsal black, female flies slightly lighter in color.

Eggs: oval-white, with hexagonal reticulation on the surface.

Larvae: Mature larvae dark yellow, thin in front and thick in the back, maggot-shaped.

Pupa: oval, dark brown.

Life habits: to the larvae into the soil pupation overwinter, the second spring in early May, mid-May feathering eggs, adults are lively and good at flying, generally early morning when the temperature is low and the humidity is high in the spinach leaf back eggs, 4 5 grains are fan-shaped arranged together, the larvae hatch and then sneak into the leaves for harm.

Control methods of spinach leaf miner fly: (1) Agricultural control: the implementation of autumn and winter irrigation to destroy the overwintering environment of overwintering pupa and reduce the base number of overwintering insects. Ploughing in spring and applying fully decomposed manure can reduce the damage of the first generation.

2) Pharmaceutical prevention and control: In the peak period of egg hatching, Dan can use 40% chrysanthemum emulsifiable concentrate 3000 4000 times liquid, or 20% rapid killing butadiene emulsifiable concentrate 3000 times liquid Li Zhen, or deltamethrin emulsifiable concentrate 3000 times liquid spray, 7 10 days before harvest.