Common insect pests of Ginkgo biloba

Camphor silkworm

The distribution and damage of this pest mainly occurred in Fujian, Guangdong, Guangxi, Hunan, Hubei, Jiangxi, Zhejiang, Jiangsu, Henan and other provinces (autonomous regions). The larvae gnawed on the leaves of Ginkgo biloba, and in serious cases, they could eat up all the leaves.

Biological characteristics: one generation a year.

The pupa overwintered in the cocoon in the branches and bark gaps. The emergence period of adults begins in early January in Guangdong, in mid-February, in Fujian, from late February to early March, and from late March to early March in Zhejiang, and from late March to early April. Adults can mate soon after Eclosion, and adults have strong phototaxis. Eggs are laid on branches and are composed of dozens to more than a hundred eggs. the eggs are arranged neatly in a single layer and are covered with black villi, so they are not easy to find. The larvae moved one after another from February to April, and the 1st and 3rd instar larvae were fed in groups, and the damage was dispersed after the 4th instar. The mature larvae were cocooned and pupated from late May to early June to the end of July.

Prevention and cure method

① collects cocoons to kill pupae; taking advantage of the insect's characteristics of long pupal period and dense cocoons, it organizes manpower to tear the cocoons off trees in winter and bury them or burn them with soil.

② light trap. The adults were trapped and killed by black light during the peak period of adult Eclosion from February to March every year.

Chemical control of ③. When the wind was calm in the morning and evening, 741 dichlorvos intubation smoke agent was released in the ginkgo orchard to control the 1st and 4th instar larvae. It can also be sprayed with 65% trichlorfon emulsion 500 × 800 times to control 1st and 3rd instar larvae. After 4 years old, it was sprayed with 500 times liquid of 90% trichlorfon crystal.

④ biological control. At the beginning of rainy season, Beauveria bassiana can be used to control Beauveria bassiana with good effect.

Ginkgo silkworm moth

Distribution and harm

Ginkgo silkworm moth, also known as white fruit silkworm, commonly known as white caterpillar. It mainly occurs in Heilongjiang, Jilin, Zhejiang, Henan, Guangxi, Taiwan and other provinces (autonomous regions). The larvae are omnivorous, feeding not only on the leaves of ginkgo biloba, but also on the leaves of Mongolian oak, walnut, willow, camphor, maple poplar, salt wood, cherry blossom, park, crape myrtle, hazel, chestnut, persimmon, plum, pear, apple and so on. When it is serious, it can eat all the leaves of the whole plant, resulting in bare crown and reduced seed production. According to a survey in Haiyang Township, Lingchuan County, Guangxi, due to the harm of this insect, ginkgo production has been reduced by more than 60%. It not only affects the yield of the current year, but also affects the flowering and fruiting of the following year. Individual seriously injured ginkgo biloba trees died.

Biological characteristics

The ginkgo silkworm moth has one generation a year in Guangxi. The egg period starts from the middle of September of the previous year to about 240 ~ 250 days in May of the following year. The larval active stage is from the end of March to the beginning of April, the larval stage is about 60 days, the cocoon begins in the middle of July, the pupal stage is about 40 days after a week, the adult stage is about 10 days in early September, the adult Eclosion period is about 10 days, mating and oviposition is completed from the first ten days of September to the middle of September. Generally, it lays eggs 3 times or 4 times, and a female moth can lay more than 250 eggs. The eggs are concentrated in piles or arranged in a single layer, and most of them are found in the cracks or depressions of the epidermis of the old trunk, which are located above lm below 3m of the trunk. The hatching of the eggs was very irregular, and the newly hatched larvae clustered at the egg block and began to feed on the tree after 1 hour. The larvae liked to gather before the 3rd instar, began to disperse gradually at the 4th and 5th instar, and moved alone at the 5th and 7th instar, usually feeding during the day. In a day, the food intake is the largest among workers 10, 00, 00, 14 and 00.

Prevention and cure method

① removed the eggs artificially in winter and killed the mature larvae or burned the cocoons in the middle and late July.

② light trap. The adult has phototaxis and strong flying ability. The female moth traps and kills the adult with black light before laying eggs in September, and the effect is good.

③ biological control. During the female oviposition period (September), Trichogramma can be released artificially, and the parasitism rate can reach more than 80%.

Chemical control of ④. Spraying 90% trichlorfon 1500 times 2000 times, or 50% dichlorvos 1500 times 2000 times, or fish rattan essence 800 times, or 25% insecticidal double 500 times, the control effect is good. The control effect on the 3rd instar larvae is especially obvious.

Super-small leaf roll moth of Ginkgo biloba

Distribution and harm

The insect mainly occurs in Guangxi, Zhejiang, Anhui, Jiangsu, Hubei, Henan and other provinces (autonomous regions). At present, it is only found that the insect harms ginkgo biloba, and the larvae eat into the short branches and the growing branches in the same year, which can make the leaves and young fruits of the short branches all wither and fall off, and the long branches wither.

Biological characteristics and the relationship between occurrence and environment

The insect has one generation a year and overwinters as a pupa in the thick bark.

Eclosion period of adults from early to late April of the following year

The peak period of Eclosion is in the middle of April, and the Eclosion period is 14-15 days.

The egg stage is from mid-April to early May.

The period from late April to mid-June is the larval damage period.

From late May to mid-June, the mature larvae were transferred to diapause in the bark.

Pupation occurred in the middle of November.

Adult Eclosion is mostly concentrated at 6: 00 in the morning. After spreading, the adult has the habit of standing upright on the back. After about 30min, the adult can climb to the crevice of the tree trunk and perch, so it is easy to catch. After 9: 00, it flies to the adult larva crown.

The adults mate the next day after Eclosion and begin to lay eggs 2-3 days later. A single egg is scattered on 1-2-year-old branchlets, and each branch lays 5 eggs per person.

The egg period is 8-9 days, and the egg hatching is about 80%.

The newly hatched larvae crawled to the depression at the top of the short branch and ate less. After 1-2 days, the larvae were eaten into the branch and fed laterally. The damage of larvae was mainly caused by short branches, followed by growing branches in the same year. When a short branch is damaged, it often invades the branch from the depression at the end of the branch or the wormhole at the base of the petiole.

From the middle of May to the middle of June, the larvae turn from the branches to the dead leaves, roll up the side edges of the dead leaves, live and feed in the leaves, and then eat into the bark. Most of the larvae pupate at the 2~3mm below the surface of the thick bark. The insect does the most serious harm to the aged and weakening trees. It was observed that the population density of Ginkgo biloba decreased gradually from south to north.

Prevention and cure method

According to the characteristic that adults inhabit tree trunks before 9 o'clock after Eclosion, ① artificially hunts and kills adults before 9:00 every day from early April to late April.

When the leaves and young fruits of the damaged branches withered in April, the damaged branches were artificially cut off and burned, and the larvae in the branches were destroyed in the areas where ② occurred at the beginning and the damage was mild.

③ should strengthen management and enhance tree resistance so as to reduce the damage degree of the pest.

Chemical control of ④. At the peak of adult Eclosion, the trunk was sprayed with a mixture of 250x of 50% fenitrothion EC and 2.5% deltamethrin EC at the proportion of 1:1, which killed 100% of the newly emerged adults. The first instar larvae should be eliminated in the dangerous period. The damaged branches were sprayed with 800 times of 80% dichlorvos EC or 2500 times diluted by 80% trichlorfon and 80% dichlorvos (1:1), or 1000 times mixture of 80% dichlorvos and 40% omethoate. According to the diapause habit of mature larvae transferred to bark, 2500 times of deltamethrin EC was sprayed at the end of May and the beginning of June. Or 25% deltamethrin EC and 10% cypermethrin EC were mixed with 20 parts of diesel respectively and rinsed on the base and soil of the trunk and on the backbone branches to form a wide 4cm poison ring, and the lethality rate to aged larvae was up to 100%.

Spodoptera litura

Lepidoptera, Lepidoptera. Also known as debt avoidance moth, coir moth, skin worm and so on. Distributed in subtropical and tropical regions, omnivorous, harmful to fruit trees, trees and crops. The larvae feed on leaves, twigs and young fruits. It's a disastrous pest.

Morphological characteristics

(1) Adult: dioecious. The female is wingless, 17-20 mm long, maggot-shaped, obese, small head, degenerated mouthparts, well-developed chest, protruding forechest dorsal plate apex, and yellow hairs in 7 and 8 abdominal segments. The male moth has a wingspan of 35mm and 44mm and a black adult brown. The antennae are double pectinate, the pectinate teeth are gradually smaller at the upper end, and there are 5 deep longitudinal lines on the back of the chest.

(2) eggs: massive, yellowish, laid in the protective capsule of the female moth.

(3) larvae: a total of 5 instars. There is a clear distinction between male and female from 3 years old. The female is 32-37 mm long, with dark brown head, ringlike markings on the top of the head, strong ossification of the chest dorsal plate: dark brown on the back of the abdomen, wrinkles on the surfaces of each segment, large reddish-brown spots near the subtopline and superior valve line, and brown and yellowish spots. The toe hook of the abdomen is circular. The male is small and yellowish brown.

(4) pupa: the female pupa is 22-23 mm long, nearly cylindrical, brown, with three tight chest segments and a horizontal row of small spines at the back end of the second, third and fifth segments of the abdomen. The male pupa is thin, 17-20 mm long, with protruding chest, slightly curved abdomen and a row of small spines at the back end of each segment. Cyst fusiform, cymbals ca. 62 mm; males ca. 52 mm. Branchlets and leaves are often attached to the protective capsule.

Occurrence regularity

It usually occurs one generation a year. The adults overwintered in the protective capsule. It pupated in May of the following year, mated and laid eggs in late May, hatched for about 3 weeks, and overwintered in early November. The larval stage is 310-340 days. The male moth copulates in the protective capsule, and the female falls to the ground and dies after spawning. The number of eggs laid was 1000 to 5000 eggs. The larvae spin silk and spread by the wind. It has phototaxis. The food intake increased after the age of S, and the damage was serious from July to September.

Prevention and cure method

(1) hunting and killing: collect overwintering protective bags and burn them centrally.

(2) Biological control: spray with Bacillus thuringiensis solution containing 100 million spores per milliliter.

(3) Pesticide control: the larvae were sprayed with 2.5% trichlorfon powder or 1000 times solution after hatching.

Control methods of four common insect pests in Ginkgo biloba

The growth rate of ginkgo biloba is very slow and it is a very precious plant.

Ginkgo biloba, Ginkgo biloba family, Ginkgo biloba is a deciduous tree, alias ginkgo, pu fan and so on. Ginkgo biloba is the oldest relict plant among the existing seed plants. All other plants of the same class are extinct and are known as living fossils. Ginkgo biloba is a precious tree species, which has appreciative, economic and medicinal value. However, the threat of diseases and insect pests of Ginkgo biloba is not small, the following editor will explain to you how to prevent and control the common diseases and insect pests of Ginkgo biloba.

1. Spodoptera litura

The emergence of ① adults is mainly concentrated at 6-8 o'clock and inhabit the trunk after Eclosion, so it is a good time to capture adults and destroy eggs from early April to 9 o'clock in the morning.

② cut off the withered branches and burned the dead branches and leaves on the ground together.

During the critical period of larval damage (from early April to early May), ③ sprayed the crown twice with 2.5% deltamethrin EC 3000 times, or with a mixture of 80% solution and 40% omethoate 1000 times solution.

After the larvae were eaten into the bark, ④ sprayed the trunk with dichlorvos, omethoate and diesel oil at 4:5:10, which could effectively kill the larvae. Spraying medicine to kill adults can effectively prevent adult emergence by brushing on the bark with quicklime 50kg, dichlorvos emulsion 1kg, salt 10kg and clear water 190kg before early pupae Eclosion in late March.

two。 Spodoptera litura

After ① leaves fall in autumn and winter, combined with pruning, insect cysts can also be removed and burned.

The larvae hatched by ② in June are mostly concentrated on the back of the leaves, which is the critical period of spraying. 90% trichlorfon 1000 times or 50% dichlorvos 1000 times are sprayed, and the effect is 95%.

3. Spodoptera litura

① in winter, combined with pruning to remove cocoons.

According to the phototaxis of adults, ② can be trapped and killed by black light.

During the larval stage, ③ was sprayed with 90% trichlorfon or 40% omethoate emulsion or 50% dichlorvos 1000-fold solution and Sodium dichlorvos 2000-fold solution.

④ natural enemies are black wasps, five-toothed green wasps, etc., all parasitic yellow thorn moth cocoons have a brown sunken part of the neck, should pay special attention to protection, can not be removed.

4. Bombyx mori

① adults lay their eggs in cracks or depressions in the rough epidermis of the trunk at 1-3 m, which is easy to remove. Old larvae and cocoons can also be caught in July.

② uses black light to trap and kill adults.

③ was sprayed with 2.5% enemy kill 3000 times or 50% malathion 1500 times. The dosage of aged larvae should be increased, and the insecticidal effect is more than 95%.

5. Anoplophorus alternatus

The hatched larvae of ① are between xylem and phloem, which can be shoveled with iron wire and dug out one by one.

Because of the clustering of adults, ② should seize the opportunity to organize manual hunting when the weather appears fine after rain from June to July.

Before the adults lay eggs, ③ was mixed with 1 part of stone-sulfur mixture sediment, 2 parts of clay, 10 parts of quicklime, 1 part of sulfur, 40 parts of water and a small amount of salt to form a paste in the first and middle of June, which could effectively prevent adults from spawning.

The new defecation hole of ④ was inserted with 1-2 poison sticks and sealed with yellow mud, and the control effect was 98%.

The editor hopes that everyone will prevent and control diseases and insect pests of Ginkgo biloba ahead of time, and never let the precious ginkgo be destroyed by the threat of diseases and insect pests.

Common insect pests of Ginkgo biloba and its control

Common insect pests of Ginkgo biloba: damage of Bombyx mori

In the case of serious insect pests, the leaves will be eaten up and the tree crown will be bare, which not only affects the yield, but also is not conducive to flowering and fruiting in the second year.

Prevention and cure method

① usually kills the mature larvae artificially in the middle and last ten days of July, and the cocoons are collected and burned, and the egg blocks can be removed manually in winter.

② usually uses black light to trap and kill adults in September, before female moths lay eggs.

For larvae, ③ can be sprayed with 25% insecticidal Shuang 500x solution.

Common pests of Ginkgo biloba: damage of ultra-small leaf roll moth of Ginkgo biloba

In general, the larvae eat into the short branches and growing branches, making all the leaves and fruits on the short branches withered and falling off, and the long branches withered.

Prevention and cure method

In ① in April, adults can be killed manually in the early morning.

② cut off the damaged branches artificially and burned them centrally in order to eliminate the larvae and reduce the damage.

③ strengthens the management and improves the tree resistance.

1000 times the mixture of 80% dichlorvos and 40% omethoate was sprayed during the ④ hazard period.

Common insect pests of Ginkgo biloba: termite damage

Termites are trunk pests that eat the xylem of the trunk, making it impossible for ginkgo to get a normal water supply.

Prevention and cure method

First of all, we need to determine the location of the ant nest, which can be based on termites' excretion, vents, etc., and then drill a hole and inject about 10 milliliters of insecticide plus 10% mirex. Generally speaking, the whole colony of termites can die 3-7 days after application.

Common insect pests of Ginkgo biloba: damage of tea yellow thrips

Most of them occur between June and August. Adults often gather on the back of the leaves to suck the sap of the young leaves, making the leaves lose green and turn gray. When serious, the leaves dry up and fall off.

Prevention and cure method

It can be sprayed with 50% phoxim, or 3000 times of chlorhexidine, or 1000 times of omethoate EC. The first spray is usually carried out in mid-June and the second in mid-and late July. If the pest is not serious, spray it twice.