Lepidoptera is a member of the family Diptera. At present, there are about 150 species known, but only a dozen of them have a wide range of parasitism and pose a great threat to greenhouse and field crops. First, the distribution and damage Liriomyza leaffly mainly damages the larvae between the upper and lower epidermis of the leaves, causing the leaves to appear bowed and white strips in the front, typical snake shape, tightly coiled and have a certain Regularity, with orange black and dry brown patches. The dive is 30-50 mm long and 3 mm wide, and gradually becomes wider as the larvae mature. The changes in the shape and length of the snorkel mainly depend on the type of host plant and the number of larvae in the leaves. Sometimes there are dozens of larvae on a leaf, which makes the stalks criss-cross and leaves almost all of them to eat, resulting in some or all chlorosis of leaves. Adults of leafflies can also harm plants. Female adults stab wounds on the leaves of parasitic plants, forming white engraved dot-like punctures, and feeding through engraved spawning and sucking sweat; adult males do not form engraved spots, but can feed on female adult wounds. As a result, it caused time-slip lesions, which destroyed the cells of the plant leaves and reduced the area of ​​photosynthesis. When the damage was severe, it often caused a large number of leaves to wither and fall off, premature plant failure, and even death. In addition, the body's activities can also spread a variety of viruses. Second, the occurrence of regular leaf leafhatch occurs several generations a year, the phenomenon of overlapping generations is serious, more confusion in the greenhouse generations. Leafminers generally begin to occur in mid-late and late April, and occur from May to October in their peak period, causing serious damage. The main factors affecting its occurrence are temperature, humidity and foodstuffs. The development period of leaf miner larvae is usually 3 to 8 days, and the instar age is 3 years old. It takes 14 days to complete one generation at 20°C. Adults are active during the day and begin spawning after 1 to 2 days after emergence. III. Prevention and control methods 1. Quarantine control The leaf miner has limited flying ability and weak natural diffusion ability. It mainly depends on eggs and larvae host plants (such as cuts, cut flowers, potted flowers, etc.) or it can spread long distances with potted plants such as soil and vehicles. . Therefore, the quarantine measures that can be taken are: 1 Conduct strict quarantine and immediately block and extinguish once found; 2 Infected parasites and their reproductive materials, first placed in a greenhouse for 3 to 4 days to allow the eggs to hatch, and then Larvae were chilled at 0°C for 1 to 2 weeks and they could also be treated with methyl bromide fumigation. 2. Physical control 1 In the greenhouse, the use of insect nets or other measures to prevent the entry of leaf miners is a more effective method; 2 At the beginning or end of the adult period, trap points are set in the greenhouse, and each point is placed Zhang Tiaozhi paper traps adults. 3. Biological control uses natural enemies for biological control. There are about 15 species of parasitic natural enemies of the leafminer, the most important ones are the green genus wasp, the fly fly pinnacle, the anti-crest, and the double-gray eagle. The release of these parasitoids parasitizes the eggs to the leaf miner. In the egg to control the damage. 4. Agricultural control 1 Timely removal of weeds and sundries in the greenhouse is extremely beneficial to the control of leafminers. 2 After the harvest of the former loquat crops, the stubble leaves of the plants are completely removed and treated in a centralized manner to eliminate the insect source. Before the next round of planting, use the steam or smoke fumigation method to disinfect the greenhouse. 3 When the sporadic leaves are found to be victimized, remove the worm-bearing leaves in time and concentrate on deep-buried or burned materials. Avoid throwing. 5. Chemical prevention In view of the rapid spread of leafflies, resistance to drug resistance, and difficulty in control, chemical control must pay attention to the fact that only one drug can be administered at one time and alternately. The appropriate period of prevention and treatment should be carried out before the larvae are 2 instar (3rd instar larvae of leaf miner flies) or when the length of most worms is less than 20 mm. In the initial stage of chemical control, the drug should be sprayed twice in a row, and the interval between drug use should be 3 to 5 days to reduce the density of the insect population as soon as possible to reduce the loss. After that, pest control should be controlled once every 7 to 10 days. The chemicals that can be used for chemical control are: 75% ciprofloxacin WP 3000 to 5000 times, 1.45% fast-wettable powder 1000 to 1500 times, 5% chlortetracycline 2000 times, 48% chlorpyrifos EC 1000 times .