When the weather gets hotter and hotter, the cotton bollworm starts to come out. It is not only harmful to cotton, but also to vegetables. For the cotton bollworm, the first thing need to be known is to understand their life habits and damage characteristics, so as to more effective control. In this article, through the analysis of the living habits of cotton bollworms and their own characteristics, we will share five ways to kill cotton bollworm, hope these methods are useful to you.
If you want to kill the cotton bollworm, you have to know its living habits. If we do not create a suitable living environment for it, we can control the growth and reproduction of cotton bollworm from the root. The pupae overwinter 5-10 cm underground near the rhizosphere of the host plant, and the generations overlap with the field. Most adults emerge at night and lay eggs 1-3 days after emergence. Adults hide in the shade of the day, and fly out at dusk to look for food, mate and lay eggs. The eggs are laid on the green and vigorous plants. It has certain phototaxis and chemotaxis. The larva has the habit of fruit transfer, and most of them transfer from the daytime.
Harm to crops：
The larvae mainly eat flowers and fruits, and also damage tender stems, leaves and buds. After the bud is injured, the sepals open, turn yellow and fall off. When the young fruit is eaten up, it will rot, and after part of the flesh of the mature fruit is eaten up, rain and pathogens will easily enter the fruit, causing rot and fall off, which will seriously to affect the yield. Therefore, cotton bollworm is not only a pest, it can also cause disease, we need to pay attention to it.
Prevention and control measures:
(1) Physical control
Based on the phototaxis and acidophilic habits of cotton bollworm (Helicoverpa armigera) adults, a frequency trembling insecticidal lamp was installed in cotton field to trap and kill cotton bollworm by light and food. Physical control can not only kill pests, but also has no pollution and harm, and will not produce pesticide resistance. It is a good solution, which is recommended to try.
(2) Biological control
Ladybug, mussel and trichogramma are natural enemies of bollworm. They can be used to kill bollworm by biological control, and control the density of mouth effectively. The natural enemies of cotton field can be enriched by intercropping or flower planting with cotton and wheat, rape and corn. Biological control is the same as the advantages of physical control, and it is pollution free and harmless. Most importantly, it will not make cotton Bollworms Resistant.
(3) Agricultural control
The survival rate of overwintering pupae and the number of insect population can be greatly reduced by persisting in autumn turning and winter irrigation. In order to prevent premature senescence, strengthen the ability of cotton plants to resist adversity, reduce the amount of eggs and larvae of cotton bollworm,we should strengthen the field management, sowing and transplanting into the right time, planting close and fertilizing reasonably, and take measures such as topping, pinching and spraying foliar fertilizer. Planting resistant varieties will greatly reduce the number of eggs and bollworm. In winter, deep turning and winter irrigation can destroy pupal chamber. Combined with winter irrigation, overwintering pupae can suffocate and die. The emergence rate of adult can be reduced by ploughing in time after wheat harvest.
(4) Seize the critical period
The key to control cotton bollworm is to catch the peak hatching stage of eggs or the peak development stage of young larvae. Organophosphorus pesticides and pyrethroid pesticides, such as 5% Emamectin Benzoate WDG, 5% Abamectin EC、Emamectin + Chlorfenapyr, can be used as insecticides. In the use of pesticides, do not use a single, continuous variety. All kinds of insecticides should be used alternately, which can delay the emergence and development of resistance of Helicoverpa armigera. Recommended use: Emamectin + Chlorfenapyr, mainly through stomach toxicity and contact killing effect to kill pests, through mixing or compounding, not only can reduce the dosage of pesticides, but also can delay the production of pest resistance.