Control technology of grape green bug

Prevention and control of grape green bug bug

When it comes to green bug bugs, many farmers have a headache, and in the early years they were only secondary pests, but with the substantial reduction in the use of chemical pesticides and the adjustment of agricultural industrial structure, the population of green bug bugs has increased sharply, and the harm has been aggravated year by year (figure 1). Many grape growers have suffered even more and suffered serious losses.

Fig. 1 Green bug bug whose damage is increasing year by year.

1 know green bug bug

Green bug bugs belong to Hemiptera, Miridae and Houli, which are widely distributed, have miscellaneous feeding habits and have more hosts (figure 2). It occurs 4-5 generations a year, likes warm and humid environment, and is easy to occur in large quantities when the temperature is 20-30 ℃ and the relative humidity is 80%-90%.

Fig. 2 A green bug with miscellaneous food and many hosts.

1.1 Egg

The egg is 1.2 mm long, 0.26 mm wide, yellowish green, the neck is thin, the end is obtusely round, the egg cover is light yellow, the front and back ends are high, the center is sunken, and the edge has no appendages, which looks a bit like a banana (figure 3).

Fig. 3 eggs of green bug bug (photo source: Laiyang Agricultural College)

1.2 nymph

A total of 5-year-old nymphs, newly hatched nymphs orange, and then slowly turn green, more lively, from an early age began to suck harmful young parts of the grape (figure 4).

Fig. 4 2nd instar nymph of green bug bug (source: Zheng Guofeng)

1.3 Adult

The adult worm is oval, long, yellowish green or light green, densely short hairs. The head is triangular, the compound eye is protruding, and the end of the leather sheet is slightly grayish brown where it meets the template (figure 5). Strong ability to fly, dormant during the day, mainly in the early morning and evening when it is not easy to detect.

Green bug bug oviposition is generally tender. most of the overwintering eggs are laid in grape bud scales and some eggs are laid on withered branches and fallen leaves.

Fig. 5 Adult of green bug bug (source: Yangchun March)

2 the harm of green bug bug

Green bug bugs mainly use nymphs and adults to harm undeveloped buds or newly unfolded young leaves, shoots and young fruits of grapes.

After the young leaves were damaged, needle-sized reddish-brown spots were formed at first, and then irregular holes of different sizes were formed with the growth of the leaves (Fig. 6).

Fig. 6 the initial damage of the leaf

In severe cases, there are many stab holes in the leaves, resulting in leaf shrinkage, deformity and even tearing (figure 7), the growth is blocked, the photosynthesis is greatly affected, and the production of its own nutrients is limited, which can not supply enough nutrients for plant growth. plant growth and flower bud differentiation are affected in varying degrees.

Fig. 7 seriously damaged leaves

When the young fruit is harmed by the adult or nymph of the green bug bug, the flower skin and young fruit will appear (figure 8).

Fig. 8 damage to young fruit

As the young fruit grows, the fruit surface will form small black spots on the wound (figure 9), seriously affecting the appearance of the fruit. It is worth noting that the damage caused by the green bug bug to the young fruit seems to be irreparable, equivalent to "disfiguring"!

Fig. 9 the black spot on the fruit surface caused by green bug bug

3 summary of the law of harm

Fig. 10 harm to buds

The green bug bug is generally more harmful in the early spring grape germination to the young fruit stage. Among them, the nymph of the first generation harms the tender buds of grape (Fig. 10); the nymph of the second generation harms inflorescences and young fruits; at the beginning of the third and fourth generation, many green bugs choose to "go out to work" because of the decrease of young grape tissue; and in the fifth generation, they "return to their hometown" and spawn over the winter.

The overwintering eggs of green bug bug showed strong cold resistance during the whole overwintering period and could resist low temperature in winter. 2016 is a warm winter, the insect population is bound to be too large, and the number of people who do not do a good job in clearing the garden will be even more serious. [Jishan Huayao]

The green bug bug is suitable to live in an environment with a temperature of about 20 ℃ and a relative humidity of about 80%. Therefore, the environmental conditions below 1 meter under the grape frame may be more suitable for feeding and harm; too much rainfall in the open air and humid environment in the greenhouse are conducive to its reproduction; the lower shoots are more vulnerable than the upper shoots.

Life habits are not easy to be found, and harmful symptoms are easy to be confused. For example, the symptoms of leaves are similar to those of virus disease and drug damage, and the harm of fruit is similar to that of black pox.

European and American hybrid grapes suffer less than Eurasian grapes. For example, the Red Earth suffers more seriously, while the rate of Jufeng victimization is relatively low.

4 prevention and control strategy

4.1 Agricultural physical control

The main results are as follows: (1) before burying the soil against cold, the grapes should clean up the weeds and dead branches inside and outside the orchard, bury them deeply or burn them centrally, and eliminate the overwintering eggs on the weeds and dead branches.

(2) the grapes were unearthed and put on the shelf before sprouting, scraping the old and warped skin of the branches and burning them together to eliminate the pests that overwintered in the seams of the branches. During the grape growing season, yellow boards or insecticidal lamps can be hung in the orchard to trap green bug bugs.

4.2 Chemical control

Green bug bug generally causes serious damage from early spring grape germination to pre-flowering, and the damage caused at this time has a great impact on the tree, so grasping the key period of prevention and control in early spring is an important measure to reduce the harm of green bug bug.

The main results are as follows: (1) 3-5 Bomedo stone sulfur mixture can be sprayed before germination, including ground weeds to kill overwintering eggs.

(2) during the period from germination to leaf development of new shoots, permethrin and permethrin can also be sprayed with their compound products, one more time at intervals of 7 to 10 days, and three times in orchards with serious damage, which can effectively reduce the number of green bug bugs.

4.3 Biological control

There are many kinds of natural enemies of green bug bugs, including egg parasitoids, flower bugs, lacewings, bugs, spiders and so on. While carrying out chemical control, we should pay attention to protection and try to choose insecticides with low biological toxicity to natural enemies.