Wheat age (Eurygaster integriceps), which is called the backbone bowl and is called Suneh in Arab countries, has probably spread in Iran for centuries and at least before the time of Nader Shah, but the first written report on the severity of the damage of this pest dates back to 1306. is.
Wheat age is one of the most important pests of wheat in Iran, Iraq, Turkey, Cyprus, Syria, Lebanon, Palestine, Jordan, southern Soviet Union and Greece and is prevalent in Iran in most areas. This age is mainly wheat pest but barley and Rye also attacks. In some countries, oats, sorghum, and rice have also been reported.
Insect characteristics:
The adult wheat insect is a large age, 12-14 mm long and about 8 mm wide. Its body is oval and almost wide. Its color varies from yellow-gray to black-brown and sometimes completely black, and in Varamin farmers these black ages are called rare age. In yellow people, patterns of black spots on the insect are often observed. Their heads are triangular in shape. And in the middle of the head, a narrow groove can be seen, the walls of which continue to the end of the head and meet there. They are light to yellow and gradually darken in color and turn completely black after 50-60 minutes.
Damage:
خسارت سن گندم در دوره رشد و نمو گیاه معمولا در سه مرحله: سن مادر، پوره و سن های بالغThe spring generation is done. The damage related to the first stage is done by adult male and female insects, which are called mother age, after flying from mountain heights and leaving the wintering place of adult insects to the green fields of cereals. During this period, overwintering adult insects need to feed on the sap and young green leaves of wheat in order to be ready for reproduction and spawning. They are young and nourished by food, especially gluten.As a result of this feeding, the newly formed clusters dry out and their color becomes white, which can be detected from a distance. 5. Damage to wheat stalks in a few days. The severity of damage at this stage depends on the population or density of insects per unit area. Chemical control is necessary.
The second stage of damage is done by nymphs of different ages. The nymphs of the first age do not feed on nymphs until the middle of the second age. From the third age, nymphs increase and in the fourth and fifth ages, the maximum feeding operation is performed to complete the nymph period and the emergence of new adult insects. The third stage of damage is related to the new generation adult insects that need adequate nutrition from wheat grains to continue their growth and ability to fly to mountain heights and begin their summer rest. And if the density of puree per square meter was at least more than 5, spraying is necessary.
Passing the winter:
Wintering of wheat is in the form of a complete insect in the foothills of mountains and under grasses and shrubs, especially diapause or hibernation, and in early spring, when the temperature reaches 20 degrees Celsius, the ages fly from their wintering places.
Ways to fight the pest:
One of the ways to fight this pest is through mechanics, which includes collecting and burning wintering places, as well as spraying these places.
agricultural
1. Use of early cultivars: This strategy increases mortality in the population by reducing the food supply in the body of spring adults. Of course, this solution is effective if planting and harvesting is done in a regional and coordinated manner
2- Quick and quick harvest of the product: Rajabi believes that harvesting the crop as soon as possible by reducing the weight of summer and wintering ages, will cause heavy losses during diapause on the one hand and reduce physiological reproduction in the following year on the other hand. This trend, in the long run, brings the wheat age population out of the flood state. Another issue is the reduction of qualitative damage to the age of wheat to a significant extent
3- Use of resistant cultivars: The resistance of different varieties of wheat and barley is not the same with the age of wheat, so resistant cultivars can be used to minimize pest damage. For example, based on a research project, Ghods and Roshan cultivars in irrigated wheat fields in Tehran province have shown the maximum aging. While the figures of freedom and hope have been less old.
Natural enemies
Most natural parasitism is related to Trissolcus parasitic bees and Phasia flies. Trissolcus bees, of which different species are distributed in grain farms of Tehran, Markazi, Hamedan and Lorestan provinces, and most of the natural parasitism of wheat eggs is related to bees of this genus. In recent years, chemical control has led to a decrease in the population of parasitoids, and as a result, the effect of these parasitoids on the age population of wheat is estimated at about 23%.
Parasitoid flies are a generation and spend the winter as third larvae in the general cavity of the host body. After emerging from the pupae, the flies feed on the nectar of the cruciferous plants and then spawn at the age of the mother, who has just returned from winter.
Chemical
1- Phosphorus or pyrethroid toxins can be used when the pest is concentrated to the extent of economic loss. In choosing the poison, the poison should be considered safe for natural enemies. If spraying is done in the pupal stage of parasitoid flies, it will not cause a negative effect on the parasitoid.
2- Stop spraying against maternal age and focus chemical control on nymphs. If it is necessary to spray against the mother’s age, it is better to do this after the ages have flown to the fields and before spawning.
3- It is better to fight against nymphs of the second age, for this purpose, after observing the first nymph of age 4, the control operation should be started, because it has been proven by experience, when seeing the first nymph of age 4, the predominant form of the pest population is nymphs. 2 is.
4. When the population of the second instar nymph was predominant, it used toxins such as phenytoin at a rate of 0.8 to 1 liter per hectare. Despite 20 years of use of fenitrothion toxin against wheat age, this toxin still provides acceptable control. Integrated pest management program to be used.
