Introduction to the Identification and Control Methods of Cutworms on Angelica sinensis
Angelica sinensis (scientific name: Angelica sinensis), a plant of the Apiaceae family. It is generally used as medicine. In China it is distributed in Gansu, Yunnan, Sichuan, Qinghai, Shaanxi, Hunan, Hubei, Guizhou and other places, and is cultivated everywhere. The root of Angelica sinensis can be used as medicine, and it is one of the most commonly used traditional Chinese medicines. It can also usually be used in the ingredients of braised products, and its main feature is removing fishiness and enhancing aroma, increasing the meaty and medicinal aroma of meat products.
Morphological characteristics
Perennial herb. Height 0.4-1 m. Stem erect, with longitudinal straight grooves, hairless, stem purplish. Basal leaves and lower stem leaves ovate, 2-3 times ternate or pinnately parted, ultimate lobes ovate or ovate-lanceolate, 3-lobed, veins and margins with white fine hairs; petiole with large leaf sheath; upper stem leaves pinnately divided. Compound umbel; rays 9-13; bracteoles 2-4; pedicels 12-36, densely covered with fine soft hairs; flowers white. Schizocarp ellipsoid, lateral ribs winged. Flowering period June-July, fruiting period July-September.
Cutworm, also known as “ground silkworm” and “black ground silkworm”. It belongs to the Lepidoptera, Noctuidae. The main cutworms on Angelica sinensis are the black cutworm and the yellow cutworm, and their damage conditions and control measures are the same.
1. Damage conditions The larvae damage Angelica sinensis seedlings, hiding by day and emerging at night. In the young instar stage they mostly damage tender leaves and tender tips, biting off the root stem, causing missing seedlings and broken rows.
2. Morphological characteristics The adult black cutworm has a body length of 16-23 mm and a wingspan of 42-54 mm. The female moth's antennae are filiform, and the male moth's are bipectinate. The area between the anterior margin and the outer transverse line of the forewing is dark brown. Between the inner transverse line and the outer transverse line there are obvious kidney-shaped markings, ring-shaped markings and rod-shaped markings. The hindwing is grayish white, with the veins and margin dark brown. The abdomen is gray. The egg is hemispherical, initially milky white, later turning yellow, and grayish purple just before hatching. Larvae The grown larva has a body length of 37-47 mm. The head is yellowish brown, the body is yellowish brown to dark brown, with a pale longitudinal band on the back. The body surface is rough, covered with round black small granules. The anal plate is yellowish brown, with two dark brown longitudinal bands. Pupa body length 18-24 mm. Reddish brown, glossy.
3. Occurrence pattern The adult black cutworm hides during the day and is active at night, being most active around dusk each day, and has a relatively strong taxis to black light lamps and sugar-vinegar-wine substances. Adults lay eggs on low weeds below 5 cm, and prefer to lay eggs on the undersides of leaves or tender stems close to the ground. The larvae have 6 instars in total. Before the 3rd instar, the larvae mostly gather on the host's heart leaves and tender leaves and on field weeds, and can feed day and night without entering the soil. After the 3rd instar, the larvae lurk in the surface soil layer during the day and come out at night to bite off seedlings and drag them into burrows. Mature larvae have a feigning-death habit, and when disturbed they immediately curl into a ring.
The black cutworm likes warmth and moisture. At a temperature of 18°C-26°C, a relative humidity of about 70%, and a soil moisture content of about 20%, conditions are favorable for growth, development and activity, and the damage is severe.
4. Control measures First, promptly clear field weeds, reduce transitional hosts, and eliminate eggs and young larvae. Second, set up sugar-vinegar-wine liquid in the field to trap adults, use palm fiber and burlap pieces to trap moths for egg-laying, and use paulownia leaves to trap larvae. Third, apply 50% phoxim emulsifiable concentrate at 1000 times and 2.5% deltamethrin at 1000 times solution at the root zone of seedlings to kill the pests.