What to Do When Willow Trees Get Pests? A Complete Guide to Prevention and Control Methods
Willow trees are a type of plant that we commonly plant near rivers and lakes, and their drooping willow leaves complement the lake and mountain scenery beautifully. There are more than five hundred species of willow trees, and they are widely planted in every province of our country. So during the planting process, what should be done when willow trees get pests?
I. The main pests of willow trees and their control
The leaf-eating pests of willow trees mainly include slug moths, scarab beetles, and willow leaf beetles, while the main trunk-boring pest is the longhorn beetle. When pests appear on willow leaves, control should be carried out according to the specific type of pest, and they should not all be treated the same way.
Slug moths are the general name for insects in the family Limacodidae of the order Lepidoptera, also commonly known as stinging caterpillars. They mainly harm willow leaves, usually gathering on the underside of leaves to chew them, forming translucent round spots and missing patches. Older larvae can eat many holes and notches into the leaves, and in severe cases can eat the leaves completely, affecting tree vigor. The main chemical treatment method is to spray 80% dichlorvos emulsifiable concentrate at 1200 times dilution, or 50% phoxim emulsifiable concentrate at 1000 times dilution, 50% malathion emulsifiable concentrate at 1000 times dilution, 25% phosmet emulsifiable concentrate at 1000 times dilution, 25% isocarbophos emulsifiable concentrate at 1500 times dilution, 5% fenvalerate emulsifiable concentrate at 3000 times dilution, and other such solutions during the peak larval period.
Scarab beetles are the general name for insects in the superfamily Scarabaeoidea of the order Coleoptera. Their larvae (white grubs) are one of the main underground pests and cause serious damage. Adults bite the leaves into net-like holes and notches, and in severe cases only the main veins remain; damage is even more serious when they gather in groups. Adults can be trapped and killed with lights, and during the adult occurrence period, they can be shaken down in the evening and caught. During the larval stage, holes can be made in the ground surface and poured with 50% dichlorvos at 500 times dilution or 90% trichlorfon at 500 times dilution, with good results. During the adult stage, spray 3% beta-cyhalothrin microcapsule suspension or 2% thiacloprid microcapsule suspension at 500-600 times dilution.
The cicada, also commonly called the autumn cicada, has both larvae and adults that can cause harm to willow trees. They lay eggs inside the branches, causing the epidermis at the saw-cut site to tilt up in a slanted sawtooth shape, and the damaged branches are prone to drying up and dying. The main control measures are to loosen the soil every spring before the cicadas emerge, turn out the pupal chambers, and remove the nymphs. Alternatively, from May to July, when nymphs hatch in concentrated numbers, pour 48% chlorpyrifos emulsifiable concentrate at 1000 times dilution or 50% phoxim emulsifiable concentrate at 800 times dilution onto the tree disk. During the peak adult occurrence period, spray 20% fenvalerate emulsifiable concentrate at 2000-3000 times dilution to kill the adults.
Longhorn beetles are important forestry pests and cause large losses of timber every year. Within 3-5 years they will gradually kill trees, and some trees take a little longer. In recent years, the pesticides tried mainly include dichlorvos, phosphamidon, dimethoate, chlordimeform, fenitrothion, phoxim, mevinphos, insecticides, carbaryl, omethoate, fluoroacetamide, and others, which can be sprayed or painted on the trunks.
The above are some related control methods for pests on willow trees. When cultivating willow trees, be sure to observe more often and detect and control pests early.