The number of cucumber leaves is closely related to the size and yield. Therefore, root and leaf protection has become an important measure for cucumber height, and in the measures to protect leaves, the prevention and control of pests harming leaves is the top priority. The main insect pests that cause damage to cucumber leaves are whiteflies, aphids, leaf miners and cinnabar leaf mites. The following describes the characteristics and control methods of these kinds of insect pests:
1. Whitefly.
1. Hazard characteristics.
Greenhouse whitefly adult body length 14~4.9 mm, yellowish white or white, with white wax powder all over the body. Adults and nymphs suck the sap of plants, and the affected leaves fade green, turn yellow, wilt, and even die of the whole plant. In addition, due to the rapid reproduction rate and large population of whitefly, it often gathers harm, and secretes a large amount of honey, seriously pollutes the leaves and fruits, often causes the occurrence of coal pollution disease, and makes the cucumber lose its commodity value.
2. Prevention and control methods.
1) Yellow plate trapping, yellow has a strong attraction effect on whitefly adults, set up a long yellow board in the shed (coated with a layer of sticky oil on the surface), trap and kill adult insects The effect is significant, generally 30 35 yellow plates per mu are appropriate.
2) pesticide control, when the whitefly occurs severely, it can be closed in the evening.
Use 10% smoke extinguishing agent 05 kg or 22% dichlorvos smoke agent 03 kg of closed fumigation. It can also be sprayed in the morning or evening with 10% imidacloprid wettable powder 4000 5000 times, or 3% acetamipid emulsifiable concentrate 3000 4000 times for control.
2. Melon aphid. 1. Hazard characteristics: aphids are divided into two types: winged and wingless, with adult aphids or good clusters on the back of melon leaves, young stems, growth points and flowers, and suck the juice of the plant with a needle-like prick mouthpiece, so that the cells are damaged, the growth is out of balance, the leaves are curled and shrunk to the back, the growth of the heart leaves is hindered, and the plant stops growing when it is serious, and even the whole plant dies. When the aphid is harmed, a large amount of water and honeydew are discharged, and a layer of mold stain is formed on the lower leaves, which causes mycosis to occur, impairs the physiological function of the leaves, reduces the accumulation of dry matter, not only reduces the yield but also affects the quality. Aphids also transmit many plant virus diseases, causing greater harm.
2. Prevention and control methods.
1) Use 1500 times of 10% worm-flavored wettable powder, or 1000 times of 50% anti-weiwei wettable powder for spray control.
2) Adults have a strong taxis, and yellow plates can be used to trap adults.
3. American spotted diver.
1. Hazard characteristics: American spotted submarine flies feed on the mesophyll on the front of the leaves with larvae, forming a serpentine curved or serpentine coiled insect tract with thin and then wide first, and there are alternating black insect feces arranged neatly, and the old worm road is a brown dry plaque area in the later stage, generally 1 insect 1, 1 old mature larva can sneak for about 3 a dayCentimeter. The larvae of the South American spotted diver mainly feed on the dorsal mesophyll, which mostly starts from the base of the main vein to form a curved and wide (15 2 mm), the insect tract extends along the leaf veins but is not limited by the leaf veins, and several insect channels are connected together to form feeding spots. In the later stage, it turns yellow. The damage of the two species of adult spotted loon flies is basically similar, both feed and lay eggs on the front of the leaves, stab the leaf cells, and form a nearly circular puncture hole the size of a needle tip, causing harm. The hole is light green at first, then turns white and is visible to the naked eye. Both larvae and adults can cause the death of seedlings in the whole forest, resulting in lack of seedlings and broken ridges. Damage to adult plants can accelerate leaf shedding, cause sunburn of fruits, and reduce yield.
2. Prevention and control methods.
1) Agricultural control: crop rotation with unharmed crops: proper thinning to increase field permeability;At the peak of the occurrence of pests, remove the leaves of the insects and destroy them, and after the cucumber pulls the seedlings, bury or burn the dead branches and weeds in time, and turn the surface soil with pupae to less than 20 cm to reduce the emergeration rate of the pupae.
2) pesticide control: master the larvae before the second instar (the insect tract is very small) spraying, you can choose 98% borer soluble powder 1500 2000 times liquid, or 18% avermectin emulsifiable concentrate 3000 4000 times solution, or 25% insecticidal aqueous agent 500 times solution, or 90% insecticidal single soluble powder 800 times solution, or 5% fluoropyridine urea emulsifiable concentrate 2000 times solution.
Fourth, cinnabar leaf mite.
1. Hazard characteristics.
In the northern region, it is more likely to harm newly unearthed seedlings in sheds or open fields in early spring. Adults and nymphs suck the juice of young shoots, young leaves, flowers, and young melons. The young leaves and shoots of the victim are hardened and reduced, the hairs are gray-brown or black-brown, the plant grows slowly, and the internodes are shortened. After being damaged, the young melon also hardens, and the hairs turn black, resulting in falling melons. Cucumber cinnabar leaf mite adult body is about 1 mm long, golden yellow, occurs in multiple generations every year, and the generations overlap.
2. Prevention and control methods: master the principle of agronomic prevention and control, supplemented by pharmaceutical control. Timely planting, avoid cucumber cinnabar leaf damage peak period;After the melon seedlings are unearthed, they are covered with plastic film to reduce the number of insects, and the removal of wild Solanaceae plants near the vegetable field can also reduce the source of insects. Pesticide prevention and control can be sprayed with 20% fenvalerate EC 1500 2500 times, or 20% deltamethrin EC 2000 times, or 10% ethoxymethrin EC 2000 times, or 10% bifenthrin EC 1500 times.