Four Major Pests to Focus on Preventing and Controlling in Garlic Cultivation

Garlic has medicinal properties and generally does not contract diseases, so it rarely develops illness, which is already widely known. However, garlic can only suppress the occurrence of certain diseases; it cannot suppress the harm caused by pests. For pests such as aphids, seed maggots, thrips, and leafminers, careful prevention and control should be carried out to ensure garlic quality and improve cultivation benefits:

1. Aphids

The aphids that mainly harm garlic include: turnip aphid, cotton aphid, green peach aphid, and mustard aphid, appearing respectively in yellow, green, yellow-green, and some in cherry red. When temperatures are higher, they are more favorable for continued reproduction and damage. Because these insects pierce and suck sap, they can cause garlic leaves to curl and become deformed; in severe infestations, the garlic leaves wither and die.

Prevention and control methods

1. Use 50% pirimicarb wettable powder at 10-18 grams per mu, diluted in 40-50 kg of water for spraying.

2. Spray with 40% omethoate emulsifiable concentrate at 1000-1500 times dilution.

3. Spray with 20% fenvalerate emulsifiable concentrate at 3000 times dilution.

2. Seed maggots

Seed maggots are also known as soil maggots. The main species harming garlic are the seed maggot and the onion maggot. These two flies are similar in appearance; the larvae are cream-yellow maggots, 0.7-0.9 cm in body length, with 7 pairs of fleshy protrusions at the tail end. The larvae damage garlic bulbs underground, causing the garlic tissue to gradually rot. The central leaves turn yellow due to loss of nutrient supply, and in severe cases the entire plant withers and dies.

Prevention and control methods

1. For fields where seed maggots have already occurred, when topdressing, replace various types of manure with refined organic compound fertilizer or multi-element compound fertilizer.

2. Spray with 90% trichlorfon crystal at 1000 times dilution; where dead clusters are found, root drenching can be used for control.

3. In places with convenient drainage and irrigation, continuous flooding can be carried out 2-3 times, each time for 24 hours, to suffocate the soil maggots, followed by rapid drainage.

3. Thrips

The thrips harming garlic are mostly onion thrips, often occurring in warm, dry seasons. There are 6-10 generations per year. Adults and nymphs are small in body length, light yellow or dark brown. They generally suck sap on garlic leaves and leaf sheaths, causing leaf color to fade and photosynthesis to be hindered. They cause the greatest harm to garlic grown mainly for green garlic.

Prevention and control methods

1. Spray with 40% dimethoate emulsifiable concentrate at 1000-2000 times dilution, using 50 kg of spray solution per 667 sq m.

2. Use 20% fenvalerate at 10-25 ml per 667 sq m, diluted in 50 kg of water for spraying.

4. Leafminers

Leafminers have 4 generations per year and overwinter as larvae or pupae inside host plant leaves. The larvae resemble small cylindrical maggots and mostly cause damage after autumn and in April of the following year. After the larvae burrow into the leaves, they feed on the leaf mesophyll, causing gray-white curved mines to appear on the leaf surface, seriously hindering the growth and development of garlic.

Prevention and control methods

1. Remove damaged garlic residue leaves from the field and compost or burn them to reduce the spread of pest sources.

2. Spray with 40% dimethoate emulsion at 3000 times dilution or 80% dichlorvos emulsion at 2000 times dilution.

3. Use a high-efficiency, residue-free biological pesticide, namely 2% Bacillus thuringiensis-abamectin wettable powder, at 50-60 grams of spray solution per 667 sq m, diluted in 50 kg of water for spraying.

4. Spray with 2.5% deltamethrin or 20% fenvalerate at 3000 times dilution.