Pea colorful fly

Scientific Name: Chromatomyia horticola (Goureau), Diptera, Liriomyza. Synonym: Phytomyza atricornis Meigen, P. nigricornis horticola (Gourean). Common name: pea leafminer. This pest is found throughout the country.

Host Plants: Peas, beans, cowpeas, cabbage, cauliflower, broccoli, rape, radish, lettuce, tomatoes, eggplant, garlic, and potatoes, among others.

Damage Symptoms: The larvae cause damage by tunneling within the leaves, feeding on the upper and lower epidermis. This creates winding trails that reduce the plant’s ability to photosynthesize, affecting overall growth and yield. In peas, infestation can lead to poor pod development and reduced seed quality and yield.

Morphological Features: Adults are about 2 mm in length, with a yellow head and red-brown compound eyes. The thorax, abdomen, and legs are dark gray, but the mid-thoracic plate, base of the wings, joint ends of the legs, and the posterior edges of abdominal segments are yellow. Wings are transparent with iridescent reflections. Eggs are approximately 0.3 mm long, oval, and milky white. Mature larvae measure 2–2.6 mm, smooth, and transparent. Their front end has a forked structure extending forward, while the rear has two small brown-tipped protrusions. The pupae are oblong, yellow-brown to dark brown.

Life Habits: This pest is widespread across the country. In North China, it completes 4–5 generations per year. Overwintering occurs within the leaves of host plants. In late spring and early April, the first generation of adults attacks young seedlings, particularly cruciferous vegetables, rapeseed, and peas. Damage peaks between May and June, while high summer temperatures reduce their activity. In autumn, some activity occurs but is less intense. Adults are diurnal, feeding on nectar and mating. They prefer to lay eggs on tender, green leaves, especially near the leaf tips. Each female lays 50–100 eggs, scattered individually. After hatching, larvae feed inside the leaves, creating tunnels that expand as they grow. Larvae reach maturity at the third instar, typically ending their development within the tunnels. The developmental duration varies with temperature. At 13–15°C, the egg stage lasts 3.9 days, larval stage 11 days, and pupal stage 15 days, totaling about 30 days. At 23–28°C, the stages take 2.5, 5.2, and 6.8 days respectively, with a total of around 14 days. Adult lifespan ranges from 7–20 days, dropping to 4–10 days in higher temperatures.

Prevention and Control Measures:

1. Cultural Control: Remove weeds promptly after harvest, especially along roadsides and field edges. Weeds serve as breeding grounds for the pest, so keeping these areas clean is essential.
2. Chemical Control: Apply insecticides when the first signs of infestation appear, ideally during the active adult phase (mid to late May). At this time, larvae are still in the early stages and have not yet formed tunnels. Recommended insecticides include 50% malathion EC diluted 1000–2000 times, 20% fenvalerate EC, 2.5% deltamethrin EC, 20% fenpropathrin EC diluted 6000–7000 times, or 40% phoxim EC diluted 1000 times. Spraying should be done every 7–10 days for 2–3 applications. Additionally, since adults often gather in weedy areas and along roadsides, it's important to treat these zones as well. Farmers are encouraged to implement unified control measures for better effectiveness.
3. Alternative Insecticides: If the above-mentioned agents show limited efficacy, consider using insecticides designed for Liriomyza sativae. For detailed application methods, refer to the guidelines for controlling Liriomyza sativae.

Fire Alarm Series

Fire Alarm Series,Fire Detector,WiFi Smoke Detector,Photoelectric Smoke Alarm

Guangdong Isafenest Co.,Ltd. , https://www.isfenest.com