Persimmon has strong adaptability, drought tolerance and large planting area in hilly areas of China. It is precisely because of these advantages that most persimmon orchards in China have the disadvantages of scattered planting and extensive management, which leads to a large-scale outbreak of pests and diseases and brings huge economic losses to fruit farmers. Among them, persimmon is the most serious. What is the "maggot" in persimmon meat? Why does it appear in the flesh? How to prevent it?

Preliminary understanding of persimmon worm

Persimmon stem borer (persimmon stem borer), also known as persimmon moth, heart worm and persimmon worm, is a common pest on persimmon trees and the fundamental source of "insect persimmon" with strong market reaction around 20 10. This pest has phototaxis, so its adults stay behind leaves or in dark places during the day and only come out at night. Its peak activity is from 22: 00 to 22: 00 at night, which is difficult for fruit farmers to find. The eggs of this pest are oval, 0.5 mm long and milky white. The mature larva is 9- 10 mm long, with brown head and dark purple back. The adult is about 7 mm long, with wings spread 15- 17 mm, khaki head, and purple-brown chest, abdomen and wings.

In production, the method of combining manual control with chemical control should be adopted for the control of persimmon stem worm. The control effect of manual control can only reach about 40%, which cannot fundamentally solve the problem. Therefore, it is necessary to coordinate the necessary chemical control methods. Details are as follows:

(1) manual control

The artificial control of persimmon pests mainly includes peeling, picking persimmon stalks, cleaning the garden, piling up soil, shading and picking fruits. Among them, the removal of rough skin is mainly completed before March in early spring every year, when the old warped skin on the book will be hung out in time, and then the orchard will be cleaned, buried or burned. Picking persimmon stems is mainly to remove the remaining persimmon stems and most of the diseased fruits on the tree with bamboo poles and other things in time after picking in the orchard to ensure that there are no persimmon stems on the tree. Cleaning the garden is mainly to remove garbage, bark scraping, persimmons and other sundries in the garden to reduce the existence of wintering eggs. Piling soil is mainly by using eclosion adults, and their ability to dig eggs is weak. Before emergence, pile up a mound of about 20 cm near the roots to reduce the number of eggs emerging. The tree cover is mainly aimed at the old epidermis that is difficult to scrape off at the bottom of the trunk. Before April, it is also beneficial to suffocate the overwintering eggs by using glue or white trunk, or by appropriate promotion. Fruit picking is mainly to pick orange fruit in the orchard when the first generation larvae eat fruit, and once when the second generation larvae eat fruit, so as to improve the control effect.

(2) Chemical control

At present, the following three methods are mainly used for prevention and control. One is to spray pesticides on the trunk, that is, in late May, spray high-concentration pesticides on the part of the trunk where the old Celosia cristata remains and the part of the root near the soil to eliminate adult emergence; The second is to spray it on the tree. The spraying period is generally in the two peak periods of late May and late July. The pesticide can be 20% midazolam 3000 times solution, 2 1% midazolam 2500 times solution and 2.5% midazolam 3000 times solution. The third is the application of persimmon tips. This method is suitable for small persimmon trees. In the first half of August, paint the persimmon tips with brushes and other tools. Pyrethroid pesticides are widely used.