Species and Control measures of Jujube pests in Shenmu City

Species and Control measures of Jujube pests in Shenmu City

1 species and harm of main insect pests

1.1 Jujube flying elephant

Also known as bud-eating weevil, small gray weevil, Coleoptera weevil family. Jujube flying elephant is the earliest and seriously harmful pest in the annual growth cycle of jujube trees in Shenmu jujube area. The adults began to eat the young buds and young leaves of jujube in early spring, which often ate up the buds seriously, resulting in two sprouts, delayed flowering and fruiting, resulting in low yield and poor quality of jujube fruit. One generation occurs every year, overwintering as larvae in the soil. In the following year, it pupated from late March to early April, the adults were unearthed during the sprouting of jujube trees in the middle and late April, mating and laying eggs in the first ten days of May, and the egg period was half a month. They began to hatch and go down to the soil in the middle of May, and the underground tissue of the harmful plants overwintered in the near circular soil chamber after autumn. June also does harm, but it rarely causes disasters. The adult has false death, which is inactive in the morning and night, and falls to the ground after being frightened [1].

1.2 Green bug bug

Also known as forage bug bug, small bedbug, Hemiptera Pentatomidae. Nymphs and adults were used to absorb the jujube sprouts, young leaves, flower buds and young fruits. The damaged leaf buds showed chlorosis spots and became irregular holes with the growth of leaves, commonly known as "broken leaf madness". After the bud was damaged, the development stopped dying and falling off. The stem is "garlic moss branch", the injured jujube hanging can not stretch normally in a curved shape, which is called "scald disease". There are 4 or 5 generations a year, overwintering with eggs in or near the shoots of alfalfa and peas. From March to April of the following year, when the average temperature reached more than 10 ℃ and the relative humidity reached 70%, the overwintering eggs began to hatch. Nymphs were harmful to jujube trees after sprouting. Other generations occurred in early June, mid-July, mid-August and mid-September, and the generation overlap was serious. The damage was the most serious in the flowering and young fruit stage of jujube in the early and middle of May and in the middle of June, and most of the damaged fruits fell off, which seriously affected the yield. Adults have strong flying ability, often lurk during the day, are not easy to find when they are surprised and move quickly, and do harm to them in the early morning and at night.

1.3 Spodoptera litura

Also known as jujube armyworm, jujube moth, Lepidoptera. The larvae are harmful to jujube buds, leaves, flowers and fruits, and the leaves and fruits are often glued together by silking. the larvae hide to eat the leaves, eat the peel, eat the pulp around the core of the fruit, and expel the feces out of the fruit, causing the damaged fruit to turn red and fall off soon, seriously affecting the yield and quality of jujube fruit. There are three generations a year, and the pupa overwinters in the rough bark cracks at the base of the trunk and main branches of the jujube tree and in the rhizosphere topsoil. Eclosion began in late March, reached its peak in mid-April, and reached the end of Eclosion in early May. Mating occurs 2 days after Eclosion, mostly in the morning. The first generation larvae occur at the stage of sprouting and spreading leaves of jujube trees and feed on new buds and tender leaves of jujube trees. The second generation larvae occur before and after flowering, causing damage to leaves, buds, flowers and young fruits. The third generation larvae occur in the fruit coloring stage, causing damage to leaves and fruits. The larvae also had the habit of silking and sagging to transfer damage. The first and second generation larvae formed cocoons and pupated in the damaged leaves after maturing. The third generation larvae matured from the first ten days of September to the middle of October and successively climbed to the cracks in the bark to pupate through the winter. Adults lurk in weeds on the back of jujube leaves or crops under trees during the day, and are active at dawn and dusk [Jishan Huayao].

1.4 jujube inchworm

Also known as jujube buqu, jujube ulna moth, belongs to the family Lepidoptera. The larva harms the tender buds, young leaves and flower buds, and filament winding hinders the extension of branches and leaves. With the increase of larval instar, the food intake increases. In serious cases, jujube buds, jujube leaves and flower buds can be eaten up, resulting in a sharp decrease in the yield of the current year, or even no harvest. And it also affects the fruit setting rate in the coming year. There is one generation a year, and the pupa overwinters at the 10~20cm in the soil under the tree, especially in the soil within 1 m from the trunk. The emergence of Shenmu began in the first ten days of April of the following year, and it was harmful to the trees after the larvae hatched. From late May to the middle of June, the larvae climbed into the soil along the trunk and pupated in late June to overwinter.

2 prevention and control measures

2.1 Agricultural control

The main results are as follows: (1) turn the soil deeply in winter to destroy the overwintering places of jujube flying elephant, green bug bug, jujube inchworm and other pests. (2) scraping bark to kill eggs and pupae. Before the jujube tree germinates, scrape off the old warped skin, cut off the stumps with eggs, remove the dead branches, rotten fruits and weeds in the jujube forest, plug the tree hole with yellow mud, and eliminate the overwintering eggs of green bug bugs and the overwintering pupae of jujube falx moths. (3) knock on the tree and shake the worm. Using the habit of false death of jujube inchworm larva and adult jujube flying elephant, the jujube tree was knocked off the pest with a stick, and the pest was eliminated in time.

2.2 physical control

(1) banding to prevent insects. In late March, a circle of 8~10cm-wide plastic film was tied at the base of the trunk, and the joint was fastened with 3~4cm with a stapler without leaving a gap. Kill the trapping female jujube inchworm moth under the film belt every morning or evening. (2) strapping grass rope to trap and kill. Under the plastic film around the trunk, the base of the trunk was tied 2-3 times with a grass rope to induce the female jujube inchworm to lay eggs, check and replace the grass rope regularly, and burn it after changing it. (3) a bunch of grass handles. In late September, the grass handle was tied at the bifurcation of the trunk to induce the larvae of the jujube falx moth to pupate, and the grass was removed and burned in winter. (4) glue ring. Before the jujube tree germinates in spring, scraping the smooth band of 10cm with thick skin width at the height of 1m and evenly applying stickworm glue (annular seal) can effectively prevent the damage of adult jujube flying elephant and green bug nymph to the tree. (5) Light inducement. Making use of the phototaxis of jujube falx wing small roll moth and jujube inchworm adults, black light was hung in the jujube forest at night to trap and kill adults.

2.3 Biological control

Protect natural enemy insects, help natural enemies survive the winter safely, use pesticides rationally, and avoid killing natural enemies. Mass breeding and feeding of insects that release their natural enemies. The natural enemies of green bug bugs are mainly tortoise ladybug, seven-star lady beetle, Chinese lacewing, large lacewing and so on. The natural enemies of Spodoptera litura are Trichogramma. The main natural enemies of jujube inchworm are swollen tarsal wasp, silkworm fly, Caiyan wide forehead fly and so on. Protect and utilize sparrows, gray magpies, woodpeckers and other beneficial birds, frogs and other animals to control the number of pests.

2.4 Chemical control [1]

(1) from late March to early April, 50% phoxim EC 300 × 500 was evenly sprayed within 1 m under the canopy to rake the soil and kill the adult jujube flying elephant. (2) in the first and middle of April, 50% phoxim EC 2000 times, 40% omethoate 2000 times and other pesticides were sprayed during jujube germination to control adult jujube flying elephants. (3) from late April to the first half of May, 2.5% deltamethrin 6000 times, 40% omethoate 1500 times and other pesticides were sprayed to control jujube falx small roll moth and green bug nymph. Spraying 25% diflubenzuron Ⅲ 1500 times liquid and other pesticides to control jujube geometrid. (4) from mid-late June to early July, spraying 2.5% deltamethrin 6000 times, 40% omethoate 1500 times and other pesticides to control jujube falx small roll moth and green bug nymph.