Octagonal pests and diseases have always been a major problem for octagonal foresters. In the previous few issues, Xianglin's Words introduced the pest characteristics and prevention and control measures of octagonal anthrax, octagonal leaf beetle and other diseases and insect pests, and in this issue we will talk about a common and highly harmful leaf-eating pest - octagonal inchworm.
< h1 class = "pgc-h-arrow-right" > biological characteristics of octagonal inchworm</h1>
Octagonal inchworm is an insect of the lepidoptera ulladae family, which is extremely reproductive, and can reproduce multiple generations a year. In the northwest region of Guangxi, 3 generations can occur a year, in the southern region of Guangxi, 4-5 generations can occur in a year, and each generation of larvae appears: the first generation of 4-5 months, the second generation of 6-7 months, the 3rd generation of 8-9 months, the 4th generation 10-11 months. It overwinters in late November as larvae (pupae), usually in the soil layer. Most of the overwintering pupae feather in early to mid-March of the following year. Feathered into live mating, the eggs are generally laid on the back of the leaves or in the crevices of the trunk bark, in a lumpy shape, and about 300 eggs are laid per female. Feathered adults with strong phototropism.
Octagonal inchworm larvae
<h1 class="pgc-h-arrow-right" > second, octagonal inchworm is harmful</h1>
Octagonal inchworm to the larvae as a pest of octagonal trees, larvae eat octagonal leaves, flower utensils and young fruits, when the insect population density is larger, the leaves of the entire octagonal forest can often be eaten in a few days, from a distance to see the forest canopy as if it had been burned. Walking into the forest, you can hear the rustling sound of larvae eating leaves, and when there is a loud noise disturbance, the larvae can be seen hanging down. Due to leaf defects, the damaged plants have serious lack of photosynthesis, their growth is impaired, it is difficult to flower and bear fruit, and even cause the plant to die. In the worst-hit stands, it often takes several years to return to normal because the leaves are often eaten. After the 4th instar, the larvae eat a large amount and are overeating, and can eat the leaves of the entire plant in a short period of time (such as a week) when they occur. Inchworm larvae are mostly affected in clusters in March-May and September-October, and are prone to disasters during the high temperature and dry seasons. When the octagonal tree is seriously damaged, the octagonal leaves are gone, and it can be transferred to the understory miscellaneous shrubs for harm.
An octagonal forest that has been eaten by octagonal inchworms
<h1 class= "pgc-h-arrow-right" > three, in the face of such a crazy octagonal inchworm, how to prevent and control? </h1>
Octagonal inchworm needs to be prevented and controlled in a timely and continuous manner, and comprehensive forestry measures must be adopted to achieve complete control and avoid recurrence for many years. It can be comprehensively applied through the following measures.
1. Reclamation and soil. Using the habit of inchworm to overwinter into the soil, for the forest stands that occurred in the previous year and were more seriously harmful, the mid-tillage soil was carried out before the pupae were feathered in March, which could crush and kill a part of the soil in the overwintering pupae and reduce the source of insects.
2. Spray to kill insects. If the larvae are in large outbreaks and are willing to eat octagonal leaves in large quantities, they need to be sprayed urgently. It is recommended to use low-toxicity, low-residue chemistry and highly targeted and highly effective biopesticides, such as white zombie bacteria and Thuringiensis (Bt powder), so as to protect the living environment of natural enemies, give play to the natural control role of natural enemies on inchworm pests in the forest, and reduce pollution of star anise products. Spray white zombie powder in March-April, and spray larvae with Bacillus thuringiensis containing 100-200 million spores per milliliter in July-August.
Bacillus thuringiensis
3. Unleash predators. Artificial release of wasps has now been used in some places for the control of leaf-eating pest inchworm. Wasp farming is carried out under the octagonal forest where the inchworm disaster has been occurring for many years, and the use of wasps to prey on inchworm insects can also obtain economic income such as bee pupae.
wasp
Honeycomb
4. Light booby trap. Taking advantage of the phototropism of adult inchworm feathers, after late March, when the adults are gradually feathered, an appropriate number of black light lamps are laid out under the forest, and black light lamps are used to trap them at night.
5. Artificial hunting. Taking advantage of the habit of the inchworm on the tree to be disturbed and easy to fall, lay a film under the canopy, hook the branches with a bamboo pole and shake the branches of the canopy appropriately and forcefully, so that the larvae are frightened to the ground, and then collected and killed.
The inchworm was startled by the shaking and fell to the ground
Collect dropped inchworms for killing
The above methods of prevention and control of octagonal inchworm are based on the actual work experience of Xianglin and summarize the production experience of the masses in the octagonal production area. From this, we can see that octagonal inchworm is easier to control than octagonal anthracnose, as long as the prevention and control is timely, take the above five comprehensive measures, control for consecutive years, strangle inchworm in the larval stage, reduce the number of eggs laid by feathered adults, and can completely avoid the occurrence of inchworm infestation. It is hoped that the majority of octagonal foresters will actively explore the prevention and control methods of octagonal inchworm, share together, promote the progress of inchworm control technology, and benefit the octagonal industry.