Diamondback also known as hanging silk worm, is an important pest in broccoli, cauliflower, cabbage and other vegetables. Because of the biological characteristics of diamondback moth and suitable climatic conditions, enhanced resistance and irrational drug use make this pest incidence is increasing, in recent years, the dangers of diamondback moth was gradually show the increased trend.
Larva: Diamondback is typical of cruciferous vegetables pests, larvae are small budworm, its shape is very similar with cabbage armyworm, cabbage butterfly young larvae. Larvae often live in the blade back eating mesophyll, after toxic remains in the epidermis, the toxic part was show white. This insect no diapause phenomenon, happens every year. Adults: adults are small moths, more lively, flew away when frightened. When resting, the wings folded like ridge wings surface that is inclined to form three yellow-white boxes, which is its main feature. Spring and autumn were serious harm. Adults with phototaxis, eggs scattered in the dorsal, small eggs, not easy to find.
Agricultural control: rational distribution of crop varieties, avoid continuous planting cruciferous vegetables, split off the bridge of pest proliferation; after the vegetables harvest, timely clean the fallen leaves and branches, and then plowing, eliminate the winter, summer insect; get rid of the ditch weeds, reducing oviposition sites and larval diets. Physical control: diamondback moth with phototaxis, occurs in the adult stage, every 2/3 farmland set a blacklight trap to kill adults.
Promote biological control technology: According to the diamondback moth occurrence amount and resistant situation, on the one hand using spinosad, Bt, avermectin, botanical pesticides, polyhedrosis virus and other biological insecticides directly control diamondback moth; on the other hand protect the small black ants, moth Tetrastichus, Cotesia wasps and other predators populations on the vegetable fields, play a role in controlling natural enemies to control resistant pests rampant.
Chemical control: In the diamondback moth outbreaking, select high efficiency, low toxicity, low-residue pesticides to control is the most effective measures. The pesticide can be choose chlorfluazuron, stuck grams, spinosad products, chlorfenapyr, Fipronil and other ideal batch control diamondback moth insecticide. Control period lies in the eggs hatched and the larvae occurrence. According to the diamondback moth damage characteristics, emphasis on the blade back and leaf spray treatment to improve the control effect. The ratio of liquid should be accurate, should not increase concentration freely. Recommended dosage: 2.5% spinosad suspending agent 1500 times, 10% Chlorfenapyr suspending agent 1200-1500 times, 5% fipronil suspending agent (Fipronil) 2500 times.
Scientific medication, improve pest control effect: diamondback moth is a common resistance pest of cruciferous, occurred many generations, dangerous for a long time. Currently the prevention and treatment major pesticides have three categories: (1) Bacterial insecticide: such as Bt (Bacillus thuringiensis), the mechanism of such pesticides is palsy the nerve of diamondback moth larvae, damage the intestinal digestion to death. Administered dose should not too high or too low, large instar should not too high, avoid spraying at high temperatures, it is best carried out in a sunny or cloudy afternoon. (2) Antibiotics pesticides: The avermectin and Bacillus thuringiensis compound pesticide varieties have the Sue Wei and Sudan, with a strong stomach toxicity, both have contact action, to resistance diamondback moth have higher activity. (3) Insect growth regulators: such as 5% flufenoxuron EC, 5% Chlorfluazuron missible oil, and 25% diflubenzuron suspensions, etc., can inhibit insect chitin synthase activity, hindering the new epidermis formation after larvae molt, leading to death. The quick result of this drug is slightly worse, but sustained long, should have applied in the diamondback moth juvenile period, should not frequently applied, alternating applied with other pesticides.
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