Mythimna separata: hazards and control
What is Mythimna separata Walker
Mythimna separata, the northern armyworm, oriental armyworm or rice ear-cutting caterpillar, is a moth of the family Noctuidae.It is a pest with significant damage to crops such as wheat It is a pest that causes significant damage to crops such as wheat. They feed mainly on the leaves and stalks of plants, resulting in stunted growth and reduced yields.
Biology of Mythimna separata
Life cycle of Mythimna separata
The life cycle of Mythimna separata consists of four stages: egg, larva, pupa and adult. Adults lay eggs on plant leaves or soil surfaces, and the larvae hatch and begin feeding on the plant. The larval stage is the most damaging stage of Mythimna separata to crops.
Reproductive ability of Mythimna separata
Mythimna separata has an extremely strong reproductive ability, and under suitable climatic conditions, it can reproduce for many generations in a year, rapidly forming large infestations and causing serious damage to crops.
Hazards of Mythimna separata
Direct damage to wheat
Mythimna separata larvae mainly feed on the leaves and stalks of wheat, causing holes or defects in the leaves, and in severe cases, they can eat up all the leaves, leaving only the leaf veins. In addition, Mythimna separata also feeds on the stalks of wheat, affecting the mechanical strength of the plant and leading to collapse.
Impact on other crops
In addition to wheat, Mythimna separata affects a wide range of crops such as corn and rice, causing extensive agricultural losses.
Impact of environmental conditions on Mythimna separata damage
Climatic conditions such as temperature and humidity have a significant impact on the reproduction and extent of damage caused by Mythimna separata. Warm and humid environments favor the reproduction and spread of Mythimna separata.
Specific hazards of Mythimna separata on wheat
Feeding on leaves
Mythimna separata larvae mainly feed on wheat leaves, causing holes or irregular notches in the leaves, and in severe cases the leaves will be eaten completely, affecting the photosynthesis of the plant.
Stalk eating
Mythimna separata larvae also feed on the stalks of wheat, especially near the ground. This causes damage to the stalks, which affects the mechanical strength of the plant and makes it susceptible to collapse, thus affecting the growth and yield of wheat.
Impact on photosynthesis
Due to heavy leaf feeding, photosynthetic capacity is significantly reduced, resulting in stunted growth and development, inadequate grain filling and ultimately affecting wheat yield and quality.
High fertility of Mythimna separata
Under favorable climatic conditions, Mythimna separata can occur in multiple generations in a year, and the number of generations increases rapidly to form a large infestation.
Control methods of Mythimna separata
Agricultural control methods
Reasonable agricultural measures, such as crop rotation, deep plowing, and removal of weeds in the field, can effectively reduce the chance of Mythimna separata occurring.
Biological Control Methods
Utilizing natural enemies of Mythimna separata, such as predatory and parasitic insects, can effectively control the population of Mythimna separata.
Chemical Control Methods
Chemical control using insecticides is the most direct and effective method during Mythimna separata outbreaks.
Common Insecticides for Mythimna separata Control
Chlorpyrifos
Characteristics: Chlorpyrifos is a broad-spectrum organophosphorus insecticide with good control effect on many kinds of pests, and has better killing effect on Mythimna separata larvae.
Usage and dosage: Commonly spray 40% chlorpyrifos emulsifiable concentrate 1000-1500 times.
| Active ingredients | Chlorpyrifos |
| CAS Number | 2921-88-2 |
| Molecular Formula | C9H11Cl3NO3PS |
| Classification | Insecticide |
| Brand Name | Ageruo |
| Shelf life | 2 Years |
| Purity | 48% |
| State | Liquid |
| Label | Customized |
| Formulations | 0.5 Gr; 97% TC; 45% EC; 15% Gr; 36% CG; |
| The mixed formulation product | Acetamiprid 5% + chlorpyrifos 35% MEbeta-cypermethrin 3% + chlorpyrifos 27% EWChlorpyrifos 39.5% + abamectin-aminomethyl 0.5% EWChlorpyrifos 5% + isoprocarb 15% WPChlorpyrifos 45% + cypermethrin 5% EWChlorpyrifos 20% + pymetrozine 10% SE |
Chlorfenapyr
Characteristics: Chlorfenapyr is a new type of high efficient insecticide, it has good effect on Mythimna separata and other lepidopteran pests.
Usage and dosage: 10% Chlorfenapyr Suspension 1500-2000 times liquid spray.
| Product Name | Chlorfenapyr |
| CAS Number | 122453-73-0 |
| Molecular Formula | C15H11BrClF3N2O |
| Application | Insecticide |
| Brand Name | Ageruo |
| Shelf life | 2 Years |
| Purity | Chlorfenapyr 20% SC |
| State | Liquid |
| Label | Customized |
| Formulations | 240g/L SC,360g/l SC, 24% SE, 10%SC |
| The mixed formulation product | 1.Chlorfenapyr 9.5%+Lufenuron 2.5% SC 2.Chlorfenapyr 10%+Emamectin benzoate 2% SC 3.Chlorfenapyr 7.5%+Indoxacarb 2.5% SC 4.Chlorfenapyr5%+Abamectin-aminomethyl1% ME |
Integrated strategy for Mythimna separata control
Importance of Integrated Control
The control of Mythimna separata requires the combination of several methods, and a single method often fails to control its damage completely.
Combination of prevention and control
The combination of prevention and timely control can minimize the damage of Mythimna separata to crops and ensure the safety and stability of agricultural production.
Conclusion
The damage of Mythimna separata to wheat and other crops cannot be ignored, and understanding its biological characteristics, damage modes, and control methods is the key to effectively controlling the damage of Mythimna separata. Through the integrated control strategy, combining agricultural control, biological control and chemical control, the damage of Mythimna separata can be effectively reduced, and the normal growth and yield of crops can be guaranteed.
Frequently Asked Questions (FAQs)
What is the best time for Mythimna separata control?
The best time for Mythimna separata control is at the early stage of larval hatching, when the larvae have the highest sensitivity to insecticides and the control effect is the best.
How to determine whether there is Mythimna separata damage in the field?
The presence of Mythimna separata damage in a field can be determined by observing whether there are holes or irregular notches in wheat leaves and whether there are signs of stalks being eaten.
Is Mythimna separata harmful to other crops?
Yes, Mythimna separata not only harms wheat, but also corn, rice, and many other crops, causing extensive agricultural losses.
How can organic farming control Mythimna separata?
Organic farming can control Mythimna separata through ecological control methods such as crop rotation, deep plowing, and use of natural enemies, avoiding the use of chemical insecticides.
What are the safety concerns for Mythimna separata control?
When using chemical insecticides to control Mythimna separata, attention should be paid to the reasonable use of dosage to avoid impacts on the environment and human health. After use, work tools and personal protective equipment should be cleaned in time.