How to prevent and control cypress pests and diseases? Latest technical method tutorial

Cypress is a general term for plants of the cypress family. Cypress includes multiple genera such as Oriental arborvitae, Chinese juniper, Hinoki cypress, and false cypress. It is widely distributed in China, from Inner Mongolia and Jilin in the north to Guangdong and northern Guangxi in the south. Its cultivated range covers almost the entire country, and it is an excellent landscaping tree species. Let us now take a look at cypress pest and disease control techniques!

Oriental arborvitae giant aphid

1. Use natural enemies: such as the seven-spot ladybird, harlequin ladybird, sunbeam wasp, aphid wasp, large gray hoverfly, green lacewing, and aphid fly. When the spring outbreak is not severe, try not to apply pesticides; you can spray clean water to wash off the aphids, so as to protect the reproduction and development of natural enemies later.

2. Chemical control: When the outbreak is severe, spray 25% Actara water-dispersible granules or 20% Confidor soluble concentrate at 5000 times dilution. About 20 generations occur each year, the body size is relatively large, and it causes damage year-round. For control, you can use 1.2% nicotine-soap emulsifiable concentrate at 1000-1500 times dilution for spraying, and you can also spray 10% imidacloprid wettable powder at 2000 times dilution for control.

Oriental arborvitae red spider mite

1. When it does not affect tree growth and ornamental value, you can spray clean water to wash them off, or spray 0.1-0.3 degree lime sulfur mixture for cleaning.

2. Evenly scatter the granules at the bottom of the trench, then cover with soil and water thoroughly. Alternatively, in curved trenches (or opened tree basins), irrigate with 40% omethoate emulsifiable concentrate at 100 times dilution, applying 2-3 kg per cm of trunk diameter; after it seeps in, seal the basin. The effective period is long, the effect is good, and it does not pollute the air or harm natural enemies. For spraying, use acaricides such as 20% dicofol emulsifiable concentrate at 800 times dilution or 73% propargite emulsifiable concentrate at 2000 times dilution. When spraying, be sure to seize the early stage of occurrence, spray evenly, and strive to spray once in early May and once in early October each year, which can basically control mite damage.

Oriental arborvitae leaf blight

1. In autumn and winter, sweep up diseased leaves under the trees and burn them to remove the source of infection. Eliminate overwintering pathogens and reduce the first infection.

2. From May to August, spray Bordeaux mixture at 1:1:100 once every two weeks for prevention. Pay special attention to strictly controlling primary infection. If an initial infection focus is found, blockade it to prevent spread.

3. Overly dense cypress forests should be appropriately thinned to improve ventilation and light penetration in the forest and reduce conditions for disease development.

Oriental arborvitae leaf blight (leaf withering disease)

1. Prune branches moderately to improve the growing environment of Oriental arborvitae and reduce sources of infection.

2. Apply more fertilizer to promote growth.

3. During the peak period of ascospore release, spray 40% Miebingwei, or 40% carbendazim, or 40% chlorothalonil at 500 times dilution for control.

4. Select disease-resistant varieties.

Oriental arborvitae caterpillar

1. Agricultural control: Strengthen forest management, prune and fell in a timely and appropriate manner, ring-bark the trees during the pest's overwintering period, and burn the bark in a concentrated manner. During major outbreaks of larvae, manual collection can also be carried out.

2. Physical control: Based on the adult's phototaxis, set up black light traps to kill adults.

3. Biological control: This pest has many kinds of natural enemies. When the occurrence level is not large, try not to use chemical control; pay attention to protecting natural enemies, such as releasing parasitic wasps.

4. Chemical control: When larval density is high, it is best to treat early. Use aircraft low-volume spraying of 25% diflubenzuron No. 3 to control larvae, using 23-45 grams of pesticide per mu, with a spray volume of 10.5 kg; the control effect can reach 98%. Aerial control should be carried out under sunny conditions with wind force below level 3. For manual spraying of 25% diflubenzuron No. 3, a 1:1500 dilution can control larvae, with an effect of more than 90%. Generally, control should be carried out during the 2nd to 4th instars, and a small amount of pyrethroid pesticides can be added as needed.

Double-striped juniper longhorn beetle

1. Strengthen management: (1) Deeply dig and loosen the soil, dig trenches and press in green manure, and apply farmyard manure to promote rapid growth of seedlings and enhance tree vigor. (2) In winter, carry out thinning, removing pest-infested trees, weakened trees, suppressed trees, etc., so that the stand density is appropriate, ventilation and light penetration are good, trees grow vigorously, and resistance to pests is enhanced. (3) In summer, promptly cut down dead trees and wind-broken trees, remove root-collar sprouts, clear branches and twigs in the forest, and maintain forest sanitation.

2. Manual capture: (1) Before overwintering adults leave for activity, in forest land where pest damage occurred the previous year, brush whitewash onto tree trunks below 2 m to prevent adults from laying eggs. (2) During the period when overwintering adults leave for activity and mating, capture adults in the forest. (3) At the damage sites of newly hatched larvae, use a small knife to scrape open the bark and search for and kill the larvae. You can also use a wooden mallet to strike the resin-flowing spots to kill newly hatched larvae.

3. Chemical control: (1) During the adult stage, in forest areas with high pest population density and high canopy closure, dichlorvos smoke agents can be used for fumigation. (2) During the newly hatched larval stage, you can use 6% wettable benzene hexachloride, 50% methyl omethoate emulsifiable concentrate, 20% Yiguo emulsifiable concentrate, 20% shuguophosphorus emulsifiable concentrate, or 25% chlordimeform aqueous solution at 100 times dilution, or a mixture of 8% dichlorvos at 1 part and No. 1 oil (diesel or kerosene) at 9 parts, and spray tree trunks below 3 m until wet, or focus spraying on resin-flowing spots; the effect is very good.

4. Use natural enemies: During the larval and pupal stages of the double-striped juniper longhorn beetle, there are many natural enemies such as braconid wasps with stalked abdomens, sclerodermus wasps, red-headed braconid wasps, and white-bellied braconid wasps, which should be protected and utilized.