Agri Leader

Two-spotted spider mites prefer hot weather

As the temperatures continue to rise this summer, so does insect activity. While outdoor plants are most often affected by these pests, indoor plants may be infested as well. Mites are common pests of plants in central Florida. There are many species of mites that appear in the home and the garden, but the two-spotted spider mite is most active during the hottest months of the year. According to the University of Florida, IFAS Extension, over 200 species of woody plants are susceptible to infestation of two-spotted spider mites. Ornamental plants such as evergreens, ligustrum, hollies, azalea, citrus, rose and viburnum are often damaged by mite feeding. These pests also attack food crops such as squash, eggplant and tomatoes both in the home garden and in commercial fields. Strawberry growers are finding it increasingly difficult to control spider mites, one of the most important food crops in Florida. Our warm fall temperatures and mild winters are well-suited to the development of a variety of arthropods, especially two-spotted spider mites.
If you suspect your plants are sustaining spider mite damage, you can look certain places for mites and signs of feeding damage. Spider mites are very tiny, so it is best to use a magnifying glass when inspecting plants leaves. These mites have an oval shaped body and come in a variety of colors such as orange, green or yellow. Two-spotted spider mites can also have a translucent appearance. To find these tiny pests, examine the undersides of plant leaves for mites, skin casts or webbing. One way to see these mites more easily is to hold a white sheet of paper underneath plant leaves and tap the foliage sharply. This will cause mites to fall onto the white paper, where you can examine them more easily. Since these pests remove plant sap from foliage, the leaves of infested plants often appear yellow or brown and they may develop leaf spots. Eventually, heavy infestations of spider mites will cause plants to become completely defoliated and they may die. All species of spider mites place a silky web on infested plants, making this a tell-tale sign of their presence. This webbing makes it easier for mites to move from plant-to-plant. Treating spider mite infestations depends on where they are causing damage. If your indoor plants are infested, you can place them in the shower underneath a hard stream of water, two or three times a week. This will remove the mites and hopefully reduce their numbers. It is usually best to quarantine plants infested with spider mites, as they can spread to other plants rapidly. When your garden plants are sustaining mite damage, you can spray them with the water hose to remove mites from the foliage. A variety of predatory mites attack spider mites in central Florida, which helps keep them under control naturally. However, if your plants are sustaining heavy feeding damage you may need to use a chemical control product. Horticultural oils and insecticidal soaps are a good option because they kill mites and are not toxic to humans. These products work by clogging the breathing holes of mites and kills them. Before using soaps or oils, be sure to check with a professional because some species of plants are more likely to develop leaf burns than others. A variety of miticides are also available at your local garden center for mite control, but mites can develop a resistance to these products if used for prolonged periods of time so use them with care. Preventing spider mite infestations in the first place is the best way to avoid damage to your plants. In your garden, you can place certain species of plants near your ornamentals that are known to repel spider mites. Onions, garlic and cilantro are just a few plants that help keep spider mites away. Healthy plants are less likely to become infested with spider mites. Be sure your plants are getting the proper nutrients, sunlight and water each day for optimal health. Before bringing new plants into your home, always inspect them thoroughly before purchase and avoid any plants that have an unhealthy appearance. After bringing new plants home, keep them away from your other houseplants for ten days to be sure there are no pests present. Regular inspections and proper plant care are the most important aspects of controlling two-spotted spider mites. You have the best chance of keeping your plants healthy when you treat mites before they become fully established in your garden or houseplants.