Main diseases and insect pests of banyan bonsai

First, soot disease. Soot disease often occurs with aphids and scale insects under the condition of high temperature and humidity. The control measures are as follows: (1) to create ventilation and light transmission conditions for plants; (2) to reduce air humidity; (3) to scrub disease spots with a brush dipped in water; (4) to eliminate aphids and shell insects in time; and (5) to protect by spraying. From June to August, 120 times 160 times equal volume Bordeaux solution or 70% methyl thiophanate 700 times 800 times solution, or 50% carbendazim wet powder 500 times 800 times solution was sprayed every 10 to 14 days.

Second, moths. The first instar of Spodoptera litura often eats its leaves into gaps, and when the old larvae are seriously damaged, they can eat up all the leaves and twigs of the whole plant, with large food intake and rapid spread. The control of Spodoptera litura can be sprayed with 1000 times of dichlorvos emulsion and 0.1% soap, or 2000 times of quick killing, and sprayed again every 10 days or so for 2 or 3 times in a row, with good results. The banyan gray silkworm moth often eats up the banyan leaves and tender shoots by the larvae, and often eats up the banyan leaves when it occurs seriously. The banyan gray silkworm moth can be sprayed with 1000 times of trichlorfon or 1000 times of dichlorvos emulsion plus 0.1% soap, or with 3000 times of 25% fenvalerate or 2000 times of dichlorvos.

Third, aphids. Aphids have piercing and sucking mouthparts, which can secrete "honeydew" and produce more than ten generations of larvae a year. It is very harmful to flowers and plants. The damaged plants have shrunk branches and leaves, deformed leaves, induced soot disease, transmitted virus and so on. When a small number of aphids occur in potted flowers, they can be treated with a brush dipped in water to prevent spread. When aphids are seriously harmful, 40% omethoate EC 1000-1500 times, 20% methamidophos EC 2000 times, 50% methamidophos EC 1500 times can be sprayed for 2 times or 3 times. It can also be used to kill aphids and fungal pesticides E882. it can not only knock down aphids quickly, but also kill leaf mites, and has the effect of promoting plant growth and turning green leaves, with a concentration of 200 to 300 times.

4. Scale insects. There are many kinds of shell insects, including wax powder scale, tortoise wax scale and so on. The shell insect is parasitic on the tender tips, leaves or branches of flowers and plants and absorbs plant nutrients, which is a harmful pest. In order to control the wax mealy scale, 2-3 Baumetu stone-sulfur mixture can be used to kill the overwintering adults in winter. The control of tortoise wax scale should be from late May to early June every year. The larval hatching period and larval stage are carried out, and the commonly used pesticide is fenitrothion emulsion 600 times.

Fifth, banyan tube thrips. Banyan tube thrips is a kind of pest that feeds exclusively on banyan trees, which mainly harms the tender tips, buds and leaves of banyan trees. The damaged plants showed curly leaves on the front and many purple-brown spots on the back of the leaves. The control of banyan tube thrips can be controlled by 80% dichlorvos 2000 times or 50% fenitrothion emulsion 1000 times, all of which have good results, but it is best to remove the rolled leaves in time in the early stage of a small amount of occurrence and pinch the worm bodies and eggs in the rolled leaves by hand.

6. Red spider. Red spider is one of the most common pests of banyan tree, which harms plants by crawling, wind and rain, water and transfer with the host. Generally spread from the bottom up, like to move on the back of the leaves. The prevention and control of red spiders can be carried out in the nursery from May to June every year, which can be sprayed with 20% triclofenac, 1000 times of raw powder or 1000 times of triclofenac, with good results.