People often refer to people who endanger the collective as "black sheep". However, what many people don't know is that there is also a "vegetable horse" living among various vegetables. Its name is thrips . Thrips actually have nothing to do with horses. The reason why the name contains the word "horse" is because this insect likes to live on plants of the thistle family, and because it can fly and jump well, it is called "thrips". Although these insects are as small as ants, because they reproduce quickly and in large numbers, they can easily cause insect pests. If not prevented and controlled in time, they can easily cause harm to vegetables, limiting their growth and reducing their yields. Let’s get to know thrips below and have a comprehensive understanding of its characteristics and living habits so that we can prevent and control it.
Yellow thrips
A huge "family" of thrips
Thrips Insecta In the order Thysanoptera . Its larvae come in three colors: white, yellow, and orange. Correspondingly, the adults also come in three colors: yellow, brown, and black. They harm vegetables by sucking their juices. Although they are very harmful, their individuals are really small, most of them are between 0.5 and 2 mm, and few exceed 7 mm.
Thrips are a huge family in the world. There are 276 genera and more than 2,000 species of thrips found around the world. Some of them eat plants, some eat fungi, and some attack other insects. However, most species eat herbivorous thrips that live on leaves and flowers.
There are more than 600 varieties of thrips in my country. The main ones that cause harm to fruits and vegetables are melon thrips, onion thrips , rice thrips and western flower thrips .
Brown thrips
Morphological characteristics of thrips
Adult thrips come in three types: black, yellow, and brown. The mouthparts on the head are relatively far back. It does not harm vegetables by biting, but uses its mouthparts to crush vegetable leaves and suck the juice inside. There are two pairs of rosary-shaped antennae with 6 to 9 segments on the head. The wings are narrow and long, with downy edges. For some reason, its claws have degenerated, and the ends of its legs are just ball-shaped pads. The female's abdomen is conical or cylindrical.
Living habits of thrips
As long as the environment and temperature are suitable, thrips can reproduce and harm crops all year round. It affects vegetables in the open field in spring, summer and autumn, and affects vegetables in greenhouses in winter. Thrips have two peak reproduction periods each year, from March to May and throughout autumn. The peak reproduction period in greenhouses in winter is from November to December. Therefore, these time periods are important time periods for thrips control.
Most thrips do not require male insects to reproduce, and thrips are also particularly capable of reproducing. They can reproduce for 10 to 17 generations every year. Each thrip can lay up to 35 eggs at a time. The eggs can hatch in 6 to 7 days and the larvae can harm vegetables.
thrips like to live in warm and dry environments. When the temperature reaches 31°C and the humidity reaches 100%, the nymph will die because it cannot adapt to the environment. If the vegetables grown in the open air encounter continuous cloudy days and the environment where the nymphs live is filled with water, they will also die. Therefore, this weakness of thrips can be exploited to control them.
Common thrips varieties
1. Melon thrips
Melon thrips, also known as melon thrips, mainly likes melon vegetables, solanaceous vegetables and legume vegetables. Adults and nymphs use razor-sucking mouthparts to feed on heart leaves, buds, flower organs, and young juices. The injured areas of young leaves and shoots will become hard and smaller, and the hairs that have not been removed will turn gray-brown or dark brown, and the plant will grow slowly and not grow taller. If the young melons are damaged, the fruits will harden and the melon hairs will turn black, causing the melons to drop.
2. Onion thrips
Onion thrips are the larger species of thrips, with body colors ranging from light yellow to dark brown. As the name suggests, onion thrips mainly damages crops such as onions, onions, garlic and other Liliaceae vegetables. It can also harm crops such as Cucurbitaceae, Solanaceae vegetables and cotton. Greenhouse and greenhouse environments are conducive to the reproduction of onion thrips.
3. Western flower thrips
Western flower thrips is an exotic species from the Americas. It is the most harmful of all thrips species.
Western flower thrips can not only harm the stems, leaves, flowers, and fruits of vegetables, causing plants to wither, but they can also spread a variety of viral diseases. The crops it can harm include not only a variety of vegetables, but also flowers, cotton and other cash crops. The climate conditions in my country's warm southern provinces and northern greenhouses in spring, summer, autumn and winter are suitable for its hazards.
Symptoms of damage caused by thrips to vegetables
Adults and nymphs of thrips mainly harm the twigs, leaves, flowers and fruits of vegetables. Gray-white dotted and linear spots will appear on the damaged areas. The flowers of severely damaged vegetables will fall off, the leaves will dry up, and the top buds of the young shoots will not grow. The leaves with less damage will curl, some will be wavy, and the veins will turn light yellow-green.
Prevention and Control Methods
Thrips reproduce quickly and can easily cause insect disasters. It may be too late to control thrips when you find them. Therefore, the prevention and control of thrips should be based on prevention and comprehensive control. The prevention and control measures are as follows:
1. Agricultural prevention and control Weeds and dead leaves in vegetable fields should be removed frequently, and then taken out for centralized destruction, because these things contain thrips eggs, nymphs, and overwintering adults. Water frequently as thrips are most afraid of high humidity. If it is grown in a greenhouse, after the first crop of vegetables is over, if it is summer, the greenhouse can be filled with high temperature. Thrips are also afraid of high temperatures and can be killed by an environment above 31 degrees.
2, natural enemy control The natural enemies of thrips include small flower bug , hunting bug , predatory mite , parasitoid wasp , etc. Planters who have the conditions can use these natural enemies for prevention and control. In addition, some microorganisms can also kill thrips, and microbial agents can also be used in this regard.
3. Physical control Thrips, like other insects, also have color preferences. It likes blue, so you can use the blue sticky insect board to trap and kill it. If it is grown in a greenhouse, insect-proof net should be hung for protection.
4. Drug control Drug control should be carried out when thrips are still very few, because thrips reproduce too fast. If there are too many thrips, it will be impossible to prevent them by then. There are many drugs that can kill thrips. For example, 10% , imidacloprid , 1.8% , abamectin , 70% Aimela, and 20% Kangfuduo can be used. When using the medicine, dilute it according to the dilution ratio required in the instructions, spray it once every 5 days, and spray it three times in a row. Because thrips like to be active in the flowers, young leaves and tender fruits of vegetables, these places are the places where spraying is the most important. Only in this way can the thrips be killed to the greatest extent.
In short, because thrips reproduce quickly and the amount of reproduction per generation is large, it is necessary to prevent and control thrips as early as possible. Otherwise, it will be too late to control thrips after they reproduce in large numbers, and it will be difficult to control.
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