Control Methods for the Silver Y Moth Pest on Perilla

Perilla leaf can disperse exterior cold and has a relatively strong diaphoretic effect. It is used for wind-cold exterior syndromes presenting with aversion to cold, fever, and absence of sweating, and is often used together with ginger; if the exterior syndrome is accompanied by qi stagnation, it can also be used together with cyperus rhizome and dried tangerine peel. For moving qi and relieving fullness in the middle, perilla leaf is used for spleen-stomach qi stagnation, chest tightness, and nausea. Native to China, it is mainly distributed in countries such as India, Myanmar, Japan, Korea, South Korea, Indonesia, and Russia. In China, wild and cultivated varieties are found in North China, Central China, South China, Southwest China, and Taiwan, China.

Morphological characteristics of perilla leaf:

Annual herb, plant height 1-1.5 m. Stem four-angled, upright, covered with fine hairs, purple or green-purple, much branched. Leaves opposite, with long petioles, leaf blades elliptical to broadly ovate, apex abruptly acute or gradually acuminate, margins serrate, both surfaces purple, covered with soft hairs. Verticillasters form one-sided terminal or axillary racemes; each flower has one bract, ovate, apex gradually acuminate; calyx campanulate, apex 5-lobed; corolla bilabiate, purple-red or pink; stamens 4, didynamous; ovary 4-lobed, stigma 2-cleft. Nutlets nearly spherical, gray-brown. Flowering period June-July, fruiting period July-September.

Varieties and types of perilla leaf

Perilla leaf commodities are often divided into two types according to differences in character and source:

Red perilla: also known as cultivated perilla leaf, it is a cultivated product and is the mainstream commodity. Its leaf blades are mostly shrunken and curled, often broken; intact leaf blades are ovate, 5-12 cm long, 4-8.5 cm wide, leaf apex acute, margins serrate, base broadly cuneate, with petioles. The leaf blades are purple on both surfaces, or green on the upper surface and purple or purple-red on the lower surface; the upper surface is covered with sparse gray-white hairs; texture brittle and easily broken, aromatic odor, slightly pungent taste.

Green perilla: also known as wild perilla leaf, mostly wild products. It differs from red perilla in that the leaf blades are smaller, the leaf shape is gradually acuminate, both surfaces of the leaf are green or gray-green, covered with gray-white hairs, with a faint odor but carrying a grassy smell.

Control of the perilla pest silver Y moth

Damage and habits of the perilla pest silver Y moth:

Young larvae gather on the undersides of tender leaves and feed on the leaf mesophyll, leaving a layer of epidermis. After the 3rd instar, larvae spin silk and hang down, dispersing to cause damage; the amount of leaf consumed increases with instar, and they can bite leaves into holes or notches; older larvae feed on entire leaves, leaving the main veins. It generally occurs more heavily in July and August when there is abundant rain.

Control methods for the perilla pest silver Y moth:

Spray pesticide by taking advantage of the characteristic that larvae before the 3rd instar have a small food intake. You can first use 80% dichlorvos emulsion or crystalline trichlorfon at 1000 times dilution; 20% fenvalerate emulsifiable concentrate or 2.5% deltamethrin emulsifiable concentrate at 2500 times dilution, spraying 50 kg of liquid per mu.