15/11/2024
Spider mites, part of the Tetranychidae family with around 1,200 species, are a significant concern in the plant world. They belong to the Acari subclass and are usually found on the undersides of plant leaves.
What Do Spider Mites Look Like?
These pests are extremely small, less than 1 mm. They lay small, spherical and initially transparent eggs. Many of them create silk webs, which is where they get the "spider" in their name. These webs help protect them and their colonies.
Their Life Cycle
Hot and dry conditions often lead to a growth in spider mite populations. The two-spotted spider mite, for example, can hatch in 3 days and become an adult in 5 days under about 27 °C. A single female can lay up to 20 eggs daily and live for 2 - 4 weeks, producing hundreds of eggs. This fast reproduction makes them able to resist pesticides easily. They have a unique reproductive system where females can choose to produce male or female offspring. They also use ballooning to spread to new places.
Common Types
The Tetranychus urticae is very well-known and can attack many plants like peppers, tomatoes, and strawberries. The Panonychus ulmi (fruit tree red spider mite) and Panonychus citri (citrus red mite) are also important pests for commercial plants.
How to Deal with Them?
1. Predatory Mites: The Phytoseiidae family, like Phytoseiulus persimilis, eats spider mites. They can consume several adult mites or eggs each day.
2. Harpin Alpha Beta: Acaricides such as 0.5% matrine AS and 43% bifenazate SC can be applied to crops for spider mite control.
3. Environmental Changes: Changing the levels of oxygen and carbon dioxide can control spider mites. High temperatures with low oxygen and high carbon dioxide can kill them, but mild carbon dioxide increase might help them reproduce.
Spider mites are a complex pest issue. We need to use a combination of methods to protect our plants and keep the environment healthy.
