<h1>Past and Present Lives of the American Spotted Fly:</h1>
In December 1993, when the American spotted fly was first discovered in the vegetable producing area of Sanya, Hainan, China's vegetable farmers began to deal with this abhorrent pest endlessly. This uninvited guest from South America, in a very short period of time, frequently appeared in the main vegetable producing areas across the country, except for Qinghai, Tibet and Heilongjiang.
American spotted diving flies mainly parasitize crops such as nightshades and melons. 10 to 12 generations of insect infestations can occur a year, and there are also outbreaks, whether it is open or protected, the shadow of the American spotted diving fly can be seen. The American spotted fly has a short generation, but its reproductive ability is particularly strong, and the parasitic plant host is very extensive. In 1995, the American spotted fly brazenly wreaked havoc in China's main vegetable-producing areas, directly causing vegetable farmers to suffer losses of 40% of production.
<h1>The dangers of the pumpkin American spotted fly:</h1>
When you wake up in the morning and find that the front of your pumpkin leaves appears like a snake-like curved worm path, you know that the American spotted fly is coming, and it wants to eat your pumpkin leaves, ho ho your vegetable garden.
The front of the pumpkin leaf is snake-like curved crawler path, which is the process of the larvae of the American spotted diving fly nibbling on the leaf flesh inside the pumpkin leaf flesh. As the worm passage widens, the American spotted fly larvae are gradually ripening and are about to come out. We can visualize the larvae of the American spotted fly as parasites, yes. It parasitizes in the fenced tissue of pumpkin leaf flesh and feeds on leaf meat. As the serpentine worm path bends and spreads, white patches appear on the affected leaves of the pumpkin, and finally the entire pumpkin plant dies.
The adult insects of the American spotted fly are not idle, and the harm is also very serious. The adult female of the American spotted fly, it will stab the leaf flesh of the pumpkin leaf, and then without shyness, put its own eggs into the epidermis of the pumpkin leaf, and then hatch into larvae in the leaf flesh, and the larvae begin to nibble on the pumpkin leaf flesh again, continuing the endless drawing.
What are adult male American spotted fly divers doing? It is not idle, busy making love to the female, and then, like the female adult, it is also pricking the leaf flesh of the pumpkin. The infestation of adult American spotted flycatchers is also very serious, leaving scar spots on pumpkin leaves. For pumpkin seedlings, they cannot withstand the nibbling of the American spotted fly larvae, and the whole plant will die, and for adult pumpkins, the leaves are covered with insect passages and wound spots, which will accelerate the loss of green and dry off the leaves. At the same time, the nibbling behavior of the American spotted diving fly will bring about the spread of various viruses, causing immeasurable losses to the edible value and commodity value of pumpkins. In the vegetable plots that occur heavily, the rate of insect plants can reach 100%, the rate of leaf worms can reach 90%, and the loss of vegetables can reach 50% or even the harvest failure.
<h1>American spotted fly infestation rules:</h1>
First, the American spotted fly harms vegetable fields more seriously than others, and the vegetables that are framed are more seriously affected than others. The harm of the American spotted fly in the late growth period of vegetables is more serious than that of the middle growth and seedling stages. American spotted diving flies harm open-field vegetables for longer than protected areas.
Second, the American spotted diving fly is active during the day from 9 a.m. to 4 p.m., which is the active period of feeding and mating. The American spotted flying ability is average, and the natural diffusion ability is average.
Third, the American spotted diving fly is the most serious in autumn, mild in spring and summer, and generally does not occur in winter. It is active frequently in the range of 21 to 32 degrees, and the harm is even worse if the generation is short and the replacement is fast.
<h1>A few measures to control the American spotted fly:</h1>
The control measures for the pumpkin American spotted fly still start from the four aspects of agricultural control, pesticide control, physical control and biological control. However, it is recommended to take comprehensive prevention and control measures according to the law of occurrence of American spotted flying fly hazards. There are both the skills of agricultural technicians and the many years of experience in prevention and control of vegetable farmers.
First, agricultural control measures. Agricultural control should be used as the most basic control measure, because the resistance of the American spotted fly is very strong. The layout of the planting varieties can be rotated to non-parasitic crops of the American spotted diving fly, and the sowing period can also be adjusted. Crop rotation can cut off the food source of the American spotted diving fly, and the crops that the American spotted diving fly does not like such as fresh corn and leeks. Thoroughly clean up the vegetable garden, and clean up the weeds and leaves in the park before sowing the next stubble vegetables. Soil deep ploughing and soil drying, can be turned into the soil is added to kill the pupae agent, can effectively suffocate to kill the pupae, combined with deep ploughing winter irrigation to reduce the number of insect sources.
Second, pesticide control measures. Chemical agents that effectively kill American spotted flies include biological agents avermectin, sand silkworm toxins, organophosphorus and pyrethroids. At present, the pesticide control of American spotted fly in China is mainly avermectin, and the larvae of American spotted fly are strong and long-lasting. However, permethrin pesticides have a good effect on adult insects, so the above types of pesticides can be considered in rotation.
Adult control: 2.0% avermectin emulsion 4000 times liquid, 50% submerg (fly amine) wettable powder 3500 times liquid, 5% nissolan (thiamethone) emulsion 2000 times liquid mixed with 3000 times liquid. Smoke agent: 10% isopropylvir smoke 250-300g/667㎡, after use of the closed shed room after 4h ventilation. Single dose rotation: biopesticide 0.2% avermectrin (avermectin) emulsion 1500 times liquid or 25% urea no. 3 suspension 1000 times liquid, alternate use, spray once every 7 days, spray 3 times in a row; 10% cypermethrin or 4.5% high efficiency cypermethrin emulsion 2000 times liquid and 20% imidacloprid soluble liquid 4000-5000 times liquid, alternate use, spray every 7-9 days, spray 2-3 times. Larval control. 667㎡ use 11% Avi pyrimidine suspension 70mL, 5% methyl vitamin salt microemulsion 10mL or 5% acetamidine emulsion 20-30mL, spray control of water 40-50 kg.
Third, biological control measures. Selective use of pesticides to protect and support the natural enemy of the American spotted diving fly, parasitic wasps, to exercise natural control over them. Mainly for the parasitism of the American spotted diving fly larvae, in the Vegetable Garden where the American spotted diving fly isfly, the release of the Li submerged fly ji wasp and the horizontal-handled golden submersible fly ji wasp, the anti-collar cocoon bee, the submerged fly cocoon bee, etc., can implement the natural prevention and control of biological measures for the American spotted fly.
Fourth, physical prevention and control measures. Physical booby-trap control measures are also effective, mainly used in the vegetable garden of the shed protection area, and yellow plates and fly-killing paper can be used to trap the adult American spotted fly. It is mainly the use of American spotted diving flies to have a strong tendency to yellow characteristics. Other physical control measures are also very good, such as spotted fly trap core can be used with yellow plates, high temperature shed low temperature freezing shed and so on.
<h1>A few additions to the pumpkin American spotted diving fly:</h1>
The main ones are agricultural and pesticide control measures. Strengthen the monitoring and forecasting of insect conditions. In spraying pesticides, it is necessary to grasp the timing, such as the peak period of larvae and adults, and the time of spraying. The most important thing is the prevention of american spotted fly, and all localities should do a good job in plant quarantine work, such as the north-south transfer of vegetables, and the transfer of pest areas to non-pest areas.
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