Thrips are small insect about 0.5-2mm body length and rarely more than 7mm. The larvae are white, yellow, or orange, while adults are brown or black.
They have conical mouthparts that can break the epidermis of plants to absorb juice. Due to its small size, thrips are difficult to find in plants. Thrips occur all year round and have strong drug resistance.
Damage of Thrips
Thrips are a common pest with a wide range of activities. It likes to patronize both open-air crops and greenhouse crops, especially melons, fruits, and vegetables.
A thrips is easy to find on the tender new growth of plants. Young tissues such as new shoots, new leaves, tender buds, tender stems, flowers, and young fruits are all thrips food. Which makes the plant grow slowly and seriously affects the yield and quality.
Thrips Damage Symptoms
The main food source of thrips is the juice of flowers, leaves and branches, which will cause the plant to wither gradually. Therefore, it is urgent to identify thrips. An easy way to check thrips is shaking injured young leaves, buds, and fruits over a piece of clean paper.
Damage to Leaves and Shoots
Damage to Flowers and Tender Fruits
Damage to Vegetables
Thrips will destroy the growth points, flowers, leaf backs and other young tissues of vegetables, which is harmful to the quality of vegetables.
Damage to Spread Viral Diseases
In addition to directly harming plants, thrips can also spread viral diseases.
Why are thrips so hard to get rid of?
Thrips have some characteristics, which makes it difficult to permanently get rid of thrips.
Thrips dont have biological enemies and have the ability of asexual reproduction. When they are not controlled, they have a powerful expansion speed.
A thrip life cycle is very short. Thrips breed many generations a year (up to 15). When the weather is warm, thrip can be transformed in only 2 weeks from egg to adult.
Thrips eggs in the soil. One key reason why thrips are hard to eradicate is only to pay attention to killing insect audits, not eggs. Thrips’ eggs, nymphs and adults reside not only in plants, but also in soil cracks.
Adults thrip overwinter in plant debris, dead grass, or tree bark. They become active in early spring, surviving on young leaves of grass and laying eggs in plant tissue. Clearing weeds before plowing is therefore an reliable measure to avoid thrips.
This is also induced by its strong reproduce. After five times of continuous use of ethyl spinosad, which is known as a specific effect on thrips, in a greenhouse, the control effect became very poor. A new pesticide was changed to control it.
Strategies to get rid of thrips
Survival Temperature and Humidity of Thrips
Thrips survive and hatch at temperatures ranging from 23° to 28°, with humidity ranging from 40% to 70%. It’s afraid of the humid environment, thrips larvae will die at 100% humidity and 31℃. Taking advantage of this feature, We can take regular control of temperature and humidity to eliminate thrips. When thrips occur more, it is recommended to spray water and close the greenhouse at high temperature. The high temperature and humidity is enough to kill thrips.
Active Time of Thrips
Thrips tend to flower, so pesticides before planting flowering are the best. And thrips like lying in the daytime and coming out at night. Pesticide in the evening is the best.
Common drugs include 25% thiamethoxam and avermectin, ethyl spinosad and acetamiprid, ethyl spinosad + imidacloprid + Organosilicon / brown sugar, ethyl spinosad + deltamethrin + Organosilicon / brown sugar, spirulina ethyl + imidacloprid, bifenthrin + thiamethoxam. It is better to use the above formula alternately.
If you want to control thrips well, you should increase the scope of spraying pesticides and increase the dosage. Not only spray plants, but also spray the ground, and spray strictly and thoroughly. It is forbidden to use any pesticide during bee active time.
Anti insect net
If thrips are disturbed in one site, they will migrate to the buds of other plants. When moving, you can use anti thrips net to prevent it.
Generally, anti-insect nets with an aperture of less than 1mm can be used to prevent and block thrips at the vent. An insect net is considered to be the most effective physical defense due to its small mesh. Let air and water pass through while thrips are blocked, it works well to protect crops from thrips.
Blue Sticky Insect Traps
Blue attracts thrips, which can be killed by hanging blue sticky insect traps at relative height to the young leaves of the plant.
Weed Barrier Fabric
The thrips will overwinter in the soil. During the garden clearing period in winter and the beginning of spring, thrips will be cleaned up in large quantities, including thrip eggs and other insects.
The pupal stage and pre pupal stage of thrips usually occur on the ground. Rank grass on the plant surroundings can be used as the habitat of thrips, and weeds barrier fabric can be used to eliminate the habitat of thrips. Try to pull out weeds around the greenhouse.