What are the main pests and diseases of bonsai ficus trees?

1. Sooty mold. Sooty mold mostly occurs under high temperature and high humidity conditions, accompanied by aphids and scale insects. Control measures are: (1) create conditions of ventilation and light penetration for the plant; (2) reduce air humidity; (3) scrub the diseased spots with a brush dipped in water; (4) promptly eliminate aphids and scale insects; (5) spray for protection. From June to August, spray once every 10 to 14 days with 120-160 times equal-amount Bordeaux mixture, or 70% thiophanate-methyl 700-800 times solution, or 50% carbendazim wettable powder 500-800 times solution.

2. Moths. The young larvae of the ficus clearwing tussock moth often eat the leaves into notches, and when older larvae cause severe damage they can eat all the leaves and tender branches of the whole plant, with a large appetite and fast spread. To control the ficus clearwing tussock moth, spray with 80% dichlorvos emulsifiable concentrate 1000 times solution plus 0.1% soap solution, or 25% fenvalerate 2000 times solution, spraying again about every 10 days, for 2 to 3 consecutive times, with good results. The ficus grey-white silkworm moth mostly damages by its larvae eating ficus leaves and tender shoots, and when the outbreak is severe it often eats all the ficus leaves. The ficus grey-white silkworm moth can be controlled by spraying 90% trichlorfon 1000 times solution or dichlorvos emulsifiable concentrate 1000 times solution plus 0.1% soap solution, and can also be controlled by spraying 25% fenpropathrin 3000 times solution or 25% fenvalerate 2000 times solution.

3. Aphids. Aphids have piercing-sucking mouthparts, can secrete "honeydew", and can produce more than ten generations of larvae per year. They are very harmful to flowering plants. Affected plants have shrunken branches and leaves, deformed leaf shape, and are induced to sooty mold, virus transmission, and so on. When a small number of aphids occur on potted flowers, they can be brushed off with a writing brush dipped in water to prevent spread. When aphid damage is severe, promptly spray 40% omethoate emulsifiable concentrate 1000-1500 times solution, 20% fenvalerate emulsifiable concentrate 2000 times solution, 50% methamidophos emulsifiable concentrate 1500 times solution, and spraying 2 to 3 times can control them. Aphid-killing fungi and the fungal pesticide E8-82 can also be used; they knock down aphids quickly and also kill spider mites, and they have effects such as promoting plant growth and making leaf color greener, with a use concentration of 200-300 times.

4. Scale insects. There are many kinds of scale insects, and those harmful to ficus trees include the citrus mealybug and the tortoise wax scale. Scale insects parasitize the tender tips, leaves or branches of flowering plants, sucking plant nutrients, and are a relatively harmful pest. To control the citrus mealybug, use 2-3 degrees Baume lime-sulfur mixture in winter to spray and kill overwintering adults. To control the tortoise wax scale, it is suitable to do so from late May to early June each year, during the peak hatching period and young instar stage of the larvae; the commonly used pesticide is fenitrothion emulsifiable concentrate 600 times solution.

5. Ficus gall thrips. The ficus gall thrips is a pest that feeds exclusively on ficus trees, mainly harming the tender tips, tender buds and tender leaves of ficus trees, and is a piercing-sucking pest. Affected plants show curling on the upper surface of leaves and many purplish-brown spots on the underside of leaves. To control ficus gall thrips, 80% dichlorvos 2000 times solution, or 50% fenitrothion emulsifiable concentrate 1000 times solution, both have good results, but it is best to promptly remove the curled leaves at the early stage when only a small number occur, and crush the insects and eggs inside the curled leaves by hand.

6. Red spider mites. Red spider mites are the most common among the pests harmful to ficus trees, and spread to harm plants by crawling, wind and rain, water, and being carried along with host plants. They generally spread from bottom to top and like to be active on the underside of leaves. To control red spider mites, in May to June each year in the nursery, spray with 20% tetradifon wettable powder 1000 times solution or 40% dicofol emulsifiable concentrate 1000 times solution, with good results.