Blind Toona sinensis: the occurrence of blind Toona sinensis on crops and the control of bamboo blind stink weevil

Bamboo blind stink bugs, you must know this kind of pest. Then how to prevent it and eliminate its harm to agriculture? Let's take a look at it.

At present, chemical control can still effectively control bamboo blind stink bugs, but it is not suitable to apply pesticides during the continuous bamboo shoot picking period (April-October), and the bamboo clumps are gradually growing and luxuriant, which not only provides a good living environment for bamboo blind stink bugs, but also quite difficult to spray. Therefore, the appropriate time for prevention and control should be before April, after the farmers leave the mother stem in the garden, the bamboo clumps are small and sparse, so it is convenient to apply pesticides, and at this time, the population density of bamboo blind stink weevil is in a low valley, which can suppress the bamboo blind Toona weevil population as soon as possible. provide a good growth environment for bamboo and opportunities for parasitic wasps to play parasitic effects, so as to reduce the harm of bamboo blind stink bugs during bamboo shoots picking.

The ecology of bamboo blind stink bug

Bamboo blind stink elephant is slender, feet and antennae are also very long, the appearance is very similar to mosquitoes, so it is commonly known as "bamboo mosquitoes". The eggs are long egg type, about 1mm long, milky white and transparent. They are laid on the edge of the young leaves near the leaf tip and are arranged side by side in a row. The number of eggs in the egg mass varies from 3 to 52, most of which are 7-14, of which the egg mass composed of 13 eggs is the most. It is light pink when it is near hatching. The egg period is about 4 days. The nymph is emerald green and resembles an adult, and the nymph period is about 18 days. The adult is about 6-8mm, the body color is green or khaki, the female is larger than the male, the spawning tube is quite long, up to half of the body length, and beyond the wing, while the abdomen of the male is completely covered by wings. The average life span of adults is about 16-19 days. Both nymphs and adults inhabit dorsal leaf spines to suck juice for survival, causing damage to mesophyll tissue and forming neat white square food marks.

Population change of bamboo blind stink bug

Yellow sticky paper was used to investigate the population changes of bamboo blind stink bugs in the bamboo forest of Guanmiao Township, Tainan County. It was found that there were two peaks in a year. The first peak was in January, with an average of 133.6 insects attracted by sticking paper on both sides. This peak may be due to winter drought and warm winter, so that the density began to rise at the end of the year before last, then gradually decreased, and then rose again after April. The second peak appeared in July, with an average of 182.3 worms attracted by two-sided sticking paper. As the harvest period for bamboo shoots begins from April to May, farmers no longer apply pesticides, and the plants are gradually tall, with luxuriant branches and leaves, providing more food sources and habitats, so the density of bamboo blind stink bugs gradually began to reach a peak in July, and began in August. Typhoons and torrential rains will occur one after another, resulting in a rapid decline in population density. From the change of the population, it can be seen that the best time for control is from February to March, when the density of the bamboo elephant is still low, and the farmers also leave the mother stem in the garden at this time, and the bamboo clump is small and sparse, so it is more suitable to apply pesticides, which can suppress the bamboo elephant group as soon as possible.

Control methods of bamboo blind stink bug

I. physical prevention and control

Physical control is to use the color preference of bamboo blind stink bugs to trap and kill. According to the response of bamboo blind stink bug to four kinds of sticky paper (yellow, green, blue and white) in the field, the results showed that yellow was the most attractive, followed by green, blue and white. Due to the high cost of yellow adhesive paper, it is not suitable for direct use in prevention and control. However, the luring effect of yellow can be used to detect the density of bamboo blind stink bugs to understand its changes in the field, so as to grasp the timing of pesticide control.

II. Biological control

After examining the eggs of bamboo blind stink bugs, it was found that black egg wasps were parasitized. After preliminary identification, the normal eggs of Telenomus sp., bamboo blind stink bugs were pink, while the eggs parasitized by black egg wasps showed black metallic luster (pictured). There is only one parasitoid in each egg. After parasitism, the egg shell hardens, the color becomes darker, and the adult bites out of the cocoon shell during Eclosion. From the egg blocks collected in the field, it was calculated that the average parasitism rate of the eggs of Toona sinensis was 33%.

Bamboo belongs to Poaceae, Bambusoideae. It is a perennial evergreen plant. From March to April every year, buds and bamboo shoots grow from underground stems, which can be eaten. At present, the cultivated area of the whole country is about 30000 hectares, and the Tainan farm area is mainly covered with Yunlin, Chiayi, Tainan and other counties, with a planting area of about 16000 hectares, accounting for more than 50% of the country's production area. In recent years, farmers in this area rely on green bamboo (Bambusa oldhamii) shoots to increase their income, with an average unit price of about 30 yuan per kilogram, so farmers are willing to continue to grow. After joining the WTO, green bamboo shoots will have more export potential. at the same time, a bamboo shoot industry alliance will be established this year (92) to integrate the bamboo shoot industry in order to create the best value. The common bamboo pests are Mecistoscelis scirtetoides, Astegopteryxbambusifoliae, Pseudoregma bambusicola, Coclebotys coclesalis, Notobius meleagris, Rhynchophorus longimanus, Acrotaeniostola sexvittata, Acroceratitis plumosa and Gastrozona fasciventris. Among them, the damage of bamboo blind stink bug to green bamboo and Dandrocalamus latiflorus is the most serious, and the food mark exceeds the leaf area by 2/3. Farmers do not have enough understanding of insect pests, poor control techniques, failed to restrain them in time, resulting in bamboo leaves damage, a large number of yellowing, drying up, seriously affecting the yield and quality. In order to provide effective, economic and safe control measures for bamboo farmers, Tainan Farm regularly monitors the population dynamics of bamboo blind stink bugs, and discusses appropriate control opportunities and techniques, so as to provide reference for farmers.