Thrips 101: A guide to Identifying and Understanding These Tiny Pests

Thrips are tiny, slender insects that can cause damage to a wide variety of plants. In this article, we will provide a guide to identifying and understanding these tiny pests. By learning how to identify thrips, you can effectively control their populations and prevent the spread of invasive species.

Thrips Identification
Thrips are small, usually less than 1/8 inch in length, and can be difficult to see with the naked eye. They are often found on the undersides of leaves, where they feed on plant tissue. Thrips can be identified by their long, narrow bodies and fringed wings. These pests come in a variety of colors, including black, brown, yellow, and green.

How to Identify Different Types of Thrips

There are over 6,000 species of thrips worldwide, with over 600 species found in the United States alone. Thrips are found in every state in the US, but are most commonly found in warmer climates such as the southern and western states. Some species of thrips are invasive and have caused significant damage to crops and ornamental plants in the US. For example, the western flower thrips (Frankliniella occidentalis) is an invasive species that is known to cause significant damage to greenhouse-grown crops and ornamental plants in many parts of the US. In addition, the chilli thrips (Scirtothrips dorsalis) is an invasive species that is known to attack a wide variety of plants, including fruit, vegetable, and ornamental crops. It is important to properly identify the species of thrips in order to effectively control them and prevent the spread of invasive species.

1. Western Flower Thrips (Frankliniella occidentalis): These thrips are light yellow to dark brown in color and have fringed wings. They are known to attack a wide variety of plants, including vegetables, fruits, flowers, and ornamental plants. Western flower thrips are common in greenhouses and can cause significant damage to crops.
2. Onion Thrips (Thrips tabaci): Onion thrips are yellow to brown in color and have fringed wings. They primarily attack onion and garlic crops, but they can also affect vegetables like cabbage and broccoli. Onion thrips can cause stunted growth and reduced yields.
3. Tomato Thrips (Frankliniella schultzei): Tomato thrips are light yellow to brown in color and have fringed wings. They target tomato crops, as well as other vegetable and fruit crops. Tomato thrips cause leaf curling, discoloration, and reduced yields.
4. Citrus Thrips (Scirtothrips citri): These thrips are yellow to brown in color with fringed wings. They attack citrus crops, as well as other fruit and nut crops. Citrus thrips can cause reduced fruit size and quality.
5. Pea Thrips (Kakothrips robustus): Pea thrips are dark brown in color and have fringed wings. They are known to attack pea crops and other legume crops. Pea thrips cause stunted growth and reduced yields.
6. Tobacco Thrips (Frankliniella fusca): These thrips are dark brown to black in color and have fringed wings. They primarily attack tobacco, but they can also affect vegetable and fruit crops. Tobacco thrips cause leaf distortion and reduced yields.
7. Cotton Thrips (Thrips hawaiiensis): Cotton thrips are light yellow to brown in color with fringed wings. They target cotton crops, as well as other vegetable and fruit crops. Cotton thrips can cause reduced yields and quality.
8. Bean Thrips (Caliothrips fasciatus): Bean thrips are light yellow to brown in color and have fringed wings. They attack bean crops and other legume crops. Bean thrips cause leaf distortion and reduced yields.
9. Rose Thrips (Thrips fuscipennis): These thrips are light yellow to brown in color and have fringed wings. They primarily attack rose bushes and other ornamental plants. Rose thrips cause leaf curling and discoloration.
10. Avocado Thrips (Scirtothrips perseae): Avocado thrips are light yellow to brown in color with fringed wings. They primarily attack avocado trees, as well as other fruit and nut crops. Avocado thrips can cause reduced fruit size and quality.

Thrips Damage
Thrips can cause significant damage to plants, especially when present in large numbers. They feed on plant tissue, leading to discoloration, distortion, and even death. Moreover, thrips are known to transmit plant viruses, which further damage plants and reduce crop yields.

According to the University of California Agriculture and Natural Resources, thrips are a major pest of greenhouse-grown crops, causing an estimated $300 million in damage each year. They are also a major pest of ornamental plants like roses, chrysanthemums, and lilies.

Controlling Thrips
Controlling thrips can be challenging due to several factors.

1. Their small size makes them difficult to detect and target with insecticides.
2. Additionally, thrips have a short life cycle and reproduce rapidly, making it difficult to control their populations once they become established.
3. Thrips can also develop resistance to insecticides over time, further complicating control efforts.
4. Another challenge is that thrips can feed on both the leaves and flowers of plants, making it difficult to completely remove them with insecticides without damaging the plant itself.
5. Finally, some species of thrips are known to hide in plant crevices or in the soil, making them difficult to reach with insecticides.

As a result, integrated pest management strategies (IPM) that combine multiple control methods, such as cultural practices, biological control, and targeted insecticide applications, are often necessary to effectively control thrips populations.

Methods for Thrips Control

1. Cultural Controls: One of the first steps in thrips control is removing weeds and debris from around plants. Thrips can overwinter in these areas, so keeping them clear helps disrupt their life cycle.
2. Biological Controls: Introducing natural predators like ladybugs and lacewings to the garden can provide effective biological control of thrips. These predators feed on thrips, reducing their population naturally.
3. Chemical Controls: When other methods are insufficient, the use of insecticides can be considered. However, it’s important to use harsh chemical insecticides as a last resort and only when necessary. Protection Plus, registered as a natural 25b exempt insecticide, is the best insecticide for thrips that does not create insect resistance or leave harmful residue on plants and can be used as a foliar spray or soil drench.

Conclusion
In conclusion, understanding how to identify thrips is essential for effectively controlling their damage to plants. By implementing cultural controls, promoting biological controls, and using chemical controls as a last resort, you can manage thrips populations successfully. Remember to rotate the use of insecticides to prevent resistance. By adopting a comprehensive and environmentally conscious approach, you can protect your plants from thrips’ destructive effects. For more detailed information on the types of Thrips, make sure to check out this external resource.