Talking about sending and planting tobacco seedlings

Gecko is a larva or caterpillar of Noctuidae, which harms the underground or aboveground stems of tobacco. Gecko is an omnivore, which eats a lot and harms any plant except woody plants. The stems of tobacco seedlings were cut off mainly in seedbed stage, transplanting stage and shortly after transplanting, which directly caused the tobacco seedlings to lodging or indirectly weakened the stems. Spodoptera litura larvae also eat a lot of leaves of seedlings, leaving only midrib.

Ground cutworms are usually controlled by exposure to pesticides, which are applied in the soil at the base of tobacco plants or in combination with widely used fertilizers.

Aphids are divided into winged and wingless, and their body color is black. Adult aphids or shepherd's purse cluster on the back of leaves, tender stems, growing points and flowers of zucchini, and suck the juice of plants with needle-shaped sucking mouthparts, so that the cells are destroyed, the growth is out of balance, the leaves curl to the back, and the heart leaves grow in the shade. In severe cases, plants stop growing, or even the whole plant withers and dies. When aphids do harm, a large amount of water and honey dew are discharged and dripped on the lower leaves, causing mold disease, hindering the physiological function of leaves and reducing the accumulation of dry matter.

When a large number of aphids are found, they should be isolated in time, and the pests should be eliminated immediately by drugs or indigenous methods. Specific measures are as follows:

1. Prepare tobacco leaf water according to the ratio of 1: 15, soak for 4 hours and then spray.

2. Prepare a solution of washing powder, urea and water according to the ratio of 1:4:400 for spraying.

3. Spray with 10% omethoate emulsion 1000 times or malathion emulsion 1000 to 1500 times or dichlorvos EC 1000 times.

4. Myzus persicae should be covered with wax powder, and 1‰ neutral soapy water or washing powder should be added when applying any medicine.

Thrips: Because many insects of this order often inhabit the flowers of Cirsium japonicum, Cirsium japonicum and other plants, it is named Thrips. Small in size, quick in action, good at jumping, living in plant flowers and feeding on pollen and nectar, or feeding on plant buds, leaves and fruits, has become a hazard to crops, flowers and forest fruits.

Prevention and control:

① Early use of drugs to control thrips. Spraying 60 ml water of 40% dimethoate emulsifiable concentrate per mu; 50% carbaryl wettable powder was sprayed with 800 ~ 1200 times solution; Spraying 50 grams of 90% trichlorfon powder and 75 kilograms of water per mu; 10% imidacloprid wettable powder 20-30g per mu; 70% Aimeile water dispersible granule is 2g per mu.

② Using natural enemies, such as spiders and predatory thrips, to control thrips.

③ Breeding of insect-resistant varieties.

corn earworm

Noctuidae 1 species. It is a big pest in cotton boll bud stage. Distributed between 50 degrees south latitude and 50 degrees north latitude. It is distributed in all cotton areas in China, especially in North China, Xinjiang, Yunnan and other cotton areas. Adult body length15 ~17 mm. Wings spread 30 ~ 38 mm Forewings are bluish gray, taupe or auburn, and lines are dark brown and unclear. There is a dark brown line in front of the renal line; The hind wing is gray-white, with a wide band of dark brown at the end area and two connected white spots at the outer edge. The body color of larvae varies greatly, such as green, yellow and reddish. And there are brown-gray spikes on the body surface; There are small black or dark brown thorns on the ventral surface; Pupa changes from green to brown.

Prevention and control:

Parasitic natural enemies such as Trichogramma, Agkistrodon halys and flies, and predatory natural enemies such as Chrysopa, wasp and locust are known. In addition to chemical control, branches can also be trapped and killed, and corn trapping areas can be established for trapping and killing.