Cabbage, cabbage, kale, etc. are our common vegetables, their morphological characteristics are very similar, so they can be classified as a type of vegetable, that is, cruciferous vegetables. The reason why these vegetables are collectively called cruciferous vegetables, there is also a point that their insect pests are also very similar, the main pests are mainly three species, the first is lepidoptera, including small cabbage moth, vegetable green worm and beet nocturnal moth and other common pests; followed by homoptera, which contains kale aphids, peach aphids, etc.; and finally Coleoptera, including yellow-striped curved beetles, small ape leaf beetles and so on. Although the main insect pests of cruciferous vegetables are these, the main insect pests of specific varieties are also different, such as on the cabbage, the harm of the small cabbage moth and the yellow curved stripe jumping nail is more serious; on the cabbage, the harm of the small cabbage moth and the green worm is more serious, and the resistance between them in different regions and different varieties of vegetables is also different.
In particular, the small vegetable moth is becoming more and more resistant in the vegetable area, and many times it cannot be killed, and it is necessary to increase the dose to barely prevent it. Especially in kale, there are hazards between small cabbage moths and vegetable moths at the same time, their body shape is similar, especially in the juvenile age is difficult to distinguish without careful observation, so sometimes many farmers Wu treats vegetable moths as small cabbage moths to control, resulting in unsatisfactory control effects.
<h1 class= "pgc-h-arrow-right" > how to distinguish between small cabbage moths and green worms? </h1>
Cabbage moths and cabbage moths belong to the same lepidoptera, and they all have 4 forms of eggs, larvae, adult worms and pupae, so they can be distinguished from these 4 forms first, and then distinguished from the hazards of vegetables, and the larvae of small cabbage moths will use mouthparts to nibble on the leaf flesh of leaves such as cabbage, leaving a reticulated epidermal wound, while vegetable moths directly eat leaves, resulting in empty mouths and lack of carvings.
1, adult insect size, wing color is not the same
The adult size of the small cabbage moth is relatively small, similar to a toothpick, can fly, the color of the wings is gray-black, magnifying glass or microscope observation, its body size is similar to the locust, so it is usually difficult for the naked eye to see its real size, only feel that something is flying.
The adult size of the cabbage worm is relatively large, the size of the common butterfly, in fact, it is a butterfly itself, called the pink butterfly. The wings are predominantly white, and the thorax has long white or gray-black hairs, which can be seen directly through the naked eye.
Small vegetable moths are in various insect forms
2. The body size of the larvae is distinguished
The larvae of the small vegetable moth can be divided into 1-4 years old, the size and color of each age insect have certain differences, the 1-2 year old body size is very small, the color is mainly light yellow, the 3-4 year old larvae slowly become larger, the color is light green, but their body size is small at both ends, the middle is swollen, it is rice-grained, there are obvious nodes, and the body shape is like a section connected together.
The larvae of the cabbage worm are all blue-green in color, the body size is increased with age, they have 2 long lines of macula on the body, the most obvious is that the hair on the body is thick and numerous, which can be observed by the naked eye.
3, the color and shape of the pupa are different
The pupae of the small cabbage moth is gray-brown in color, resembling a coarse grain of rice, and if you look closely, you will find that its outer layer is covered with white mesh, which is often called a thin cocoon.
There are many kinds of pupae colors, common are green, gray-green or gray-yellow, etc., and the surface of the pupa has sparse black spots, the midline of the dorsal body protrudes into a ridge, and there is a yellow ridge on each side of the abdomen, which can be well distinguished from the pupa of the small cabbage moth.
4. The size and color of the egg mass are different
The egg shape of the small cabbage moth is oval, very small, difficult to find with the naked eye, the color of the eggs is pale yellow, and the adults often line 3-5 grains into pieces and produce them on the back of the leaves.
The eggs of the green worm are relatively large, rice-grained, yellow in color, usually more than a dozen eggs laid together, very conspicuous.
Vegetable green insects are in various insect states
For the distinction between small cabbage moths and cabbage moths, the difference between their egg, pupae and adult signs is quite large, and the larvae look relatively difficult to distinguish at first glance, which needs to be carefully observed: First, the body of the small cabbage moth larvae is large in the middle and small, with nodes, and the second is that the body hair of the larvae of the cabbage moth is more, which can be clearly observed.
< h1 class= "pgc-h-arrow-right" >why is the cabbage moth more difficult to beat than the vegetable worm, and the resistance is getting heavier? </h1>
1, the size of the small vegetable moth is relatively small, in the vegetable leaf back or in the core and other hidden parts of the feeding, many conventional drugs are difficult to hit, with good concealment; and the vegetable insect is larger, egg laying is also more concentrated, the host is relatively small, so it is easy to kill.
2, the small cabbage moth has a relatively strong environmental adaptability, especially to the temperature has a strong adaptability, the temperature of the adaptation range is wide, in the low temperature to 0 degrees Celsius, as high as 35 degrees Celsius can survive, but the favorite temperature of the small cabbage moth in 20-30 °C can spawn a large number of eggs between 20-30 °C; but also has a strong ability to tolerate low temperature, the larvae in -1.4 °C conditions as usual to feed, in 0 °C conditions can endure 42 days of low temperature climate.
3, the life cycle of the small cabbage moth is relatively short, the average is 15-20 days, there is a serious phenomenon of overlapping times, the need for continuous drug control, so the production of anti-insecticide spectrum, almost all the insecticides used have developed resistance, and even the biological pesticide Bt has also produced resistance. Secondly, because of the frequent spraying, coupled with the short life cycle of the small cabbage moth, the drug resistance develops rapidly, only takes about 2 years, and the level of drug resistance is very high, and the production of drug resistance will lead to a decline in the prevention and control effect, and it is currently necessary to use auxiliaries to increase the efficacy.
4, the recipe of the small cabbage moth is wide, and the planting area of cruciferous vegetables such as cabbage and cabbage is getting larger and larger, which makes the small cabbage moth have more food sources, can carry out a large number of spawning and reproduction, and the harm is more serious.
<h1 class = "pgc-h-arrow-right" > how to effectively control this headache moth? </h1>
1. Strengthen agricultural prevention and control
First of all, it is necessary to carry out reasonable rotation of the field, and the early, middle and late ripening varieties of cruciferous vegetables or varieties with different growth cycles of long and short growth cycles can be rotated with other vegetables. This reduces the accumulation of the egg base of overwintering insects and reduces the occurrence base of the following year;
Secondly, it can be planted in intervals with non-cruciferous vegetables such as legumes and solanaceae;
Finally, to carry out the pastoral cleaning work in time, the small vegetable moth will parasitize the pupa on the dead branches and rotten leaves, diseased leaves for overwintering, so it is necessary to burn in time to reduce the overwintering base.
2. Trap adult insects and reduce egg laying
Light booby-trapping, using the characteristics of adult cabbage moths with phototropism, installing black light lamps in the field to lure adult insects to come and be destroyed, or using sexual attractants to apply on the macula to trap male insects, reduce mating and spawning, and reduce harm.
3. Scientific and reasonable chemical prevention and control
Prevention and control of the appropriate period
The moth is sensitive to chemical agents in the larval stage and has low resistance, so it is the best control period, that is, the early stage of larval (1 to 2 years old).
Rational use of medication
According to the control indicators to decide whether to use drugs, if the cabbage in the seedling stage each tree has an average of 1 larva, then you can use drugs for control, cabbage grows up after the leaves are more and more compared, if the average plant has 1-2 heads can choose safe and efficient chemical agents for control, but pay attention to the rotation of agents, to avoid rapid resistance reduction control effect.
Recommended chemical agents
Chloranthrine benzamide, Bacillus thuringiensis (can be mixed with insecticide), indicotin, polycycline, carbocycline, neem, lice (egg killing), insecticidal double (egg killing), etc. In addition to being efficient for small cabbage moths, these agents are also effective against vegetable moths, so many times in the control of small cabbage moths at the same time to control the vegetable green worms, can eliminate the small cabbage moths of the potion can almost eliminate the vegetable green worms.
For kale, there is a waxy layer on the surface of its leaves, and it is difficult for conventional agents to penetrate the wax layer to reach the leaves, so sometimes the liquid medicine is like water passing through the back of the duck, and it is difficult to retain the liquid medicine and kill the moth. At this time, it is necessary to use synergistic auxiliaries to strengthen the development and permeability of the agent, and many large manufacturers' agents have added an appropriate amount of synergistic aids, so it is recommended to buy regular pesticides from large manufacturers, and the quality is guaranteed. It is recommended to use an agent that kills adult insects (including larvae) + an egg killer for a longer duration.