Introduction and control of cabbage moth

Mustard (Brassica juncea) is an annual or biennial herb of Brassica in Cruciferae. It is a famous vegetable native to China. It is a commonly used vegetable cultivated all over the country, mostly distributed in the provinces south of the Yangtze River.

Mustard (original variety) annual herbs, 30-150 cm tall, often glabrous, sometimes young stems and leaves prickly, powdery, spicy; stems erect, branched. Basal leaves broadly ovate to Obovate, 15-35 cm long, tip rounded-obtuse, base cuneate, pinnatifid, with 2-3 pairs of lobes, or indehiscent, margin notched or dentate, petiole 3-9 cm long, with lobules; lower stem leaves smaller, margin notched or dentate, sometimes obtusely serrate, not clasping. Upper leaves of stem narrowly lanceolate, 2.5-5 cm long and 4-9 mm wide, margin inconspicuously sparsely dentate or entire.

Racemes terminal, elongated after anthesis; flowers yellow, 7-10 mm in diam.; pedicels 4-9 mm long; sepals yellowish, oblong-elliptic, 4-5 mm long, erect; petals Obovate, 8-10 mm long, 4-5 mm long. Siliques linear, 3-5.5 cm long and 2-3.5 mm wide, petals with 1 prominent midrib; beak 6-12 mm long; fruiting pedicel 5-15 mm long. Seeds globose, ca. 1 mm in diam., purple-brown. The flowering period is from March to May and the fruiting period is from May to June.

What is the mustard pest, Plutella xylostella, and what are the hazards?

Plutella xylostella is commonly known as square moth, diamondback moth, small green worm, hanging ghost, tip and so on. It belongs to Lepidoptera and Plutella xylostella.

1) the damage status of Plutella xylostella is a worldwide pest, which is distributed all over the country, and the damage is more serious in the south. It is one of the important pests of vegetables. Plutella xylostella mainly harms as many as 40 species of cruciferous vegetables and other cruciferous hosts, such as cabbage, radish, cauliflower, cabbage, mustard, turnip, rape and so on. In addition, it can also harm tomatoes, potatoes, ginger, onions and so on.

The first instar larvae of Plutella xylostella do harm to the hidden leaves, drill and feed on the mesophyll, leaving two layers of epidermis. Or eat in petioles and veins. Feed on the leaves after 2 years old, leaving only a layer of epidermis, commonly known as opening the skylight. The larger larvae bite the leaves into small holes. Larvae like to harm the heart leaves of seedlings and affect the development of vegetables. In the case of damage to the remaining seed plant, the tender leaves, stems, pods and seeds can be eaten, and the seed yield can be affected. Control methods of Plutella xylostella caused by mustard pests

The annual continuous cropping of cruciferous vegetables should be avoided in ① rational distribution of vegetable fields. The early, middle and late varieties are planted with other vegetables, or at a certain distance. To prevent the continuous occurrence of serious damage to pests.

② cleans the field to remove the residual branches and leaves in time after harvest, take them out of the field and bury them or burn them, kill the larvae or pupae, and reduce the density of insects in the field.

③ lights and sex attractants can be installed in the field to trap and kill adults during the occurrence period of adults. It is also available to trap and kill the female moth with the same day's feathering female moth, take the end of the abdomen, use dichloromethane, alcohol and other solvents for rough extraction, apply the crude extract on the paper, hang it in the field to attract male moths, trap and kill.

④ is sprayed in time at an early age. The commonly used agents are Bacillus thuringiensis 500-1000 times, or BT emulsion, 100g per mu, or thiazuron No. 1 and No. 3 500-1000 times, or 40% chrysanthemum EC 2000-3000 times, or 40% chrysanthemum horse EC 2000-3000 times, or 10% cypermethrin EC 2000-3000 times, or 20% fenvalerate EC 2000-3000 times, or 5% nongmonte 3000 times. Or use 5000 times liquid of Jinan-79 strain (Pieris rapae granulosis virus), or 1000-1500 times liquid of 50% Batan wettable powder, or 10000-20000 times liquid of 10.8% Caesar EC.