Oregosa, also known as the white spider, is also known as the white spider. It is a worldwide pest that is mainly distributed in warm areas or in greenhouses. It has a wide range of food habits, and it not only harms tea plants, eggplants, peppers, soybeans, potatoes, etc., but also many ornamental and wild plants are seriously harmed. Because the carcass is small and difficult to find with the naked eye, reports of damage in fruit trees in the past were only found in citrus and grapes. When we found out in 2003 in greenhouses in Beijing, we found that this quail seriously harmed apple seedlings. For this reason, we conducted in-depth research.
Basic morphological characteristics and biological characteristics
1. Morphological features: females are 170 to 249 microns in length and 111 to 164 microns in width. The body is broadly oval, yellow to yellowish green. The forehead is wide, the limbs are cylindrical and extend forward. Feet at the distal end of the foot are large and rod-shaped, and there are two small bars at the proximal end. The foot II bar is slightly smaller than the distal bar of the I bar, and is slightly smaller. Foot II, III claw degradation, claw pads developed. Males are 159 to 190 microns long and 100 to 122 microns wide. The body is approximately prismatic, with the widest part of the posterior half, yellowish or yellowish green, and the copulator apparently extending toward the upper part of the body. Eggs are oval in shape, transparent, with well-arranged vesicular processes, flat on the underside of the egg, and clinging to the surface of the leaf.
2. Biological characteristics: The life cycle of the tea plant is short. It takes 7 to 11 days to complete the generation at 20°C to 26°C. It takes only about 4 days to complete a generation at a temperature of 28°C to 30°C. Because the temperature for the development of this grasshopper is 11.7°C, the area where the average monthly temperature is higher than this temperature can occur throughout the year, but in the winter, the duration of the generation can reach 37 days.
Transmission and Harmful Symptoms The occurrence of tea yellow pods is greatly affected by temperature and temperature. Eggs, larvae, and crickets require relatively high humidity. They must be above 80% relative humidity to hatch and develop normally. Humid and wet conditions in the soil are favorable for its occurrence. Its harm spreads and it is actively transferred by itself; the second is wind or artificial transmission. The young shoots of apple seedlings grow thin and weak after injury, and the shoots of the shoots become dark and eventually stop growing. The young leaves were injured in the early stage after being wounded and rolled inwards in a tube shape. In the middle period of stretching, the leaves curled outwards and lost their luster, and they showed tiny yellow spots on the back of the leaves, which stopped growing and became brittle. Old leaves are no longer harmful after aging.
Prevention and control Because the body shape is very small, it is difficult to find it with the naked eye. In the event of harm symptoms, it is difficult for general pesticides to work. Prevention and control work should be based on prevention and comprehensive prevention and control.
First, the greenhouse must be completely disinfected before use to eliminate the source of infection. Ensure greenhouse ventilation and reduce air humidity. Can not be mixed with solanaceae, leguminous and melon crops and other host plants to cut off the food chain and reduce the population density. Should be sprayed 0.5 ~ 1 Baume degree of lime sulfur agent in winter, can kill most of the overwintering population, reduce the amount of occurrence the following year. Once onset, remove severely damaged leaves. Timely removal of dead and fallen leaves in the greenhouse and nearby treatments can reduce the risk of migration of some of the residual insect sources.
Second, protect and use natural enemies and reduce the number of medications. The natural enemies of this species are rich in resources. The main species are small pods, hummocks and various predators. If we grasp the law of occurrence of natural predators of major dominant species in different periods, coordinate various prevention and control measures, avoid spraying natural pesticides during the peak period, give full play to the role of natural enemies, and reduce the number of medications, we will achieve good control effects.
Third, chemical control. In the event of major pests can be applied to control. Our prevention and control work showed that the use of 0.9% edavanin (effective ingredient avermectin) EC 1500 times, spray once every half month, can effectively prevent and treat. According to another report, 73% of Ketek (propynyl sulfite miticide) EC 2500-3000 times, 20% fluorenone (pyridazinone acaricide) EC 2000 ~ 2500 times, 5% Nisolol (thiazolone acaricide) emulsifiable concentrate 2000 times is effective.
Basic morphological characteristics and biological characteristics
1. Morphological features: females are 170 to 249 microns in length and 111 to 164 microns in width. The body is broadly oval, yellow to yellowish green. The forehead is wide, the limbs are cylindrical and extend forward. Feet at the distal end of the foot are large and rod-shaped, and there are two small bars at the proximal end. The foot II bar is slightly smaller than the distal bar of the I bar, and is slightly smaller. Foot II, III claw degradation, claw pads developed. Males are 159 to 190 microns long and 100 to 122 microns wide. The body is approximately prismatic, with the widest part of the posterior half, yellowish or yellowish green, and the copulator apparently extending toward the upper part of the body. Eggs are oval in shape, transparent, with well-arranged vesicular processes, flat on the underside of the egg, and clinging to the surface of the leaf.
2. Biological characteristics: The life cycle of the tea plant is short. It takes 7 to 11 days to complete the generation at 20°C to 26°C. It takes only about 4 days to complete a generation at a temperature of 28°C to 30°C. Because the temperature for the development of this grasshopper is 11.7°C, the area where the average monthly temperature is higher than this temperature can occur throughout the year, but in the winter, the duration of the generation can reach 37 days.
Transmission and Harmful Symptoms The occurrence of tea yellow pods is greatly affected by temperature and temperature. Eggs, larvae, and crickets require relatively high humidity. They must be above 80% relative humidity to hatch and develop normally. Humid and wet conditions in the soil are favorable for its occurrence. Its harm spreads and it is actively transferred by itself; the second is wind or artificial transmission. The young shoots of apple seedlings grow thin and weak after injury, and the shoots of the shoots become dark and eventually stop growing. The young leaves were injured in the early stage after being wounded and rolled inwards in a tube shape. In the middle period of stretching, the leaves curled outwards and lost their luster, and they showed tiny yellow spots on the back of the leaves, which stopped growing and became brittle. Old leaves are no longer harmful after aging.
Prevention and control Because the body shape is very small, it is difficult to find it with the naked eye. In the event of harm symptoms, it is difficult for general pesticides to work. Prevention and control work should be based on prevention and comprehensive prevention and control.
First, the greenhouse must be completely disinfected before use to eliminate the source of infection. Ensure greenhouse ventilation and reduce air humidity. Can not be mixed with solanaceae, leguminous and melon crops and other host plants to cut off the food chain and reduce the population density. Should be sprayed 0.5 ~ 1 Baume degree of lime sulfur agent in winter, can kill most of the overwintering population, reduce the amount of occurrence the following year. Once onset, remove severely damaged leaves. Timely removal of dead and fallen leaves in the greenhouse and nearby treatments can reduce the risk of migration of some of the residual insect sources.
Second, protect and use natural enemies and reduce the number of medications. The natural enemies of this species are rich in resources. The main species are small pods, hummocks and various predators. If we grasp the law of occurrence of natural predators of major dominant species in different periods, coordinate various prevention and control measures, avoid spraying natural pesticides during the peak period, give full play to the role of natural enemies, and reduce the number of medications, we will achieve good control effects.
Third, chemical control. In the event of major pests can be applied to control. Our prevention and control work showed that the use of 0.9% edavanin (effective ingredient avermectin) EC 1500 times, spray once every half month, can effectively prevent and treat. According to another report, 73% of Ketek (propynyl sulfite miticide) EC 2500-3000 times, 20% fluorenone (pyridazinone acaricide) EC 2000 ~ 2500 times, 5% Nisolol (thiazolone acaricide) emulsifiable concentrate 2000 times is effective.
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