The cabbage moth, also known as *Mamestra brassicae*, is a member of the family Noctuidae in the order Lepidoptera. It is commonly referred to as the cruciferous caterpillar due to its preference for plants in the Brassicaceae family. This pest has a wide range of host plants, with over 100 species across 45 families. The primary vegetables affected include cabbage, broccoli, cauliflower, radishes, rapeseed, eggplants, beans, melons, and potatoes.
**Harmful Characteristics:**
Newly hatched larvae tend to cluster on the underside of leaves, feeding on the leaf tissue while leaving the epidermis intact. As they grow, they become more scattered, creating holes in the leaves. By the fourth instar, they feed voraciously at night, often leaving only the veins and petioles. Older larvae can burrow into the heart of cabbages or other cruciferous crops, causing significant damage and promoting bacterial soft rot, which reduces the market value of the produce.
**Morphological Features:**
Adults measure 18–25 mm in length and have a wingspan of 45–50 mm. Their wings are gray-brown with distinct patterns: a grayish-black ring on the front wings, a kidney-shaped marking, and three small white dots near the leading edge. The submarginal line is white and fine, with a black dot along the outer edge. The hind wings are plain gray without any markings.
**Eggs:**
The eggs are hemispherical, with a diameter of 0.6–0.7 mm. They feature radial ridges and cross-ribs on the surface. Initially yellow-white, they turn dark purple before hatching.
**Larvae:**
The final instar larvae can reach up to 29.1 mm in length. Newly hatched larvae are blackish green, and their color varies from light green to dark brown. They have white dots on the back and grayish-white lines along the sides, with black streaks on the dorsal surface. Younger larvae move like rulers due to the absence of the first two pairs of prolegs.
**Pupae:**
Pupae are about 20 mm long, reddish-brown or dark brown, with a central dark vertical band and long spines. They typically pupate in the topsoil 6–10 cm deep.
**Life Habits:**
The life cycle varies by region. In Tibet, it completes one generation per year, while in Sichuan and Hunan, it may complete 3–4 generations. Overwintering occurs in the soil, often under host plants or weeds. Adults emerge in spring when temperatures rise above 15°C, with peak activity during the night. Females are more attracted to light than males and lay between 500–1,000 eggs over their lifespan. Eggs hatch within 4–5 days at 23.5–26.5°C. Larvae feed primarily at night, with the most severe damage occurring in the later instars.
**Environmental Preferences:**
Cabbage moths thrive in warm, humid conditions, with an ideal temperature range of 18–25°C and humidity of 70–80%. Extreme temperatures or humidity levels outside this range are unfavorable.
**Natural Enemies:**
Several natural enemies help control populations, including parasitic wasps like *Trichogramma* and predatory insects such as ants, spiders, and ladybugs. In Chongqing, certain nematodes and parasites play a key role in suppressing second-generation larvae.
**Control Methods:**
1. **Cultural Control:** Deep plowing after harvest helps reduce overwintering populations. Removing infested leaves and larvae promptly can also limit spread.
2. **Physical Control:** Using black lights or sweet-and-sour traps (sugar, vinegar, water in a 10:1:1:8 ratio) can effectively capture adults.
3. **Biological Control:** Applying *Bacillus thuringiensis* (Bt) before the third instar is effective. Releasing *Trichogramma* wasps at 6–8 points per 667 m², every 5 days for 2–3 times, also helps.
4. **Chemical Control:** Pesticides should be applied when third-instar larvae are active and vulnerable. Alternating insecticides prevents resistance, and sufficient water coverage ensures better efficacy.
Medical Spray,Bissell Antibacterial Carpet Cleaner Solution,Clorox Commercial Solutions Clorox Disinfecting Wipes,Swiffer Wet Jet Antibac
Jilin Manyitang Pharmaceutical Co., Ltd , https://www.likangpharmaceutical.com