What are Spider Mites?
Spider mites are tiny, versatile pests that affect almost any type of vegetation including fruit trees, evergreen trees, grasses and shrubs. These pests belong to the family of arachnids; thus are more closely related to spiders and ticks. They survive by sucking sap from plants.
How to Identify Spider mites
Spider mites measure less than a millimeter in length. They possess characteristics that make them clearly
distinguishable from insects. For instance, they have eight legs, unsegmented bodies, and lack wings or antennae.
They come in a variety of colors which include green, red, yellow or brown depending on the species. An example of a spider mite found in America is the two-spotted spider mite. This specie has two dark spots on its back and, like other spider mites, uses its needle-like mouthpart called a stylet to pierce plant cells and suck sap. When found in large numbers, these two-spotted spider mite pests can cause serious damage to fruits, vegetables, and flowering plants.
Since spider mites are small enough to be difficult to identify without a magnifying glass, it’s essential that gardeners use a hand lens or look for other signs of spider mites which include the silk-like webbing they produce during an infestation.
The Life Cycle of Spider Mites
Spider mites can develop several generations in any given year. Depending on the species and the time of year, these pests can complete an entire generation in only a few weeks.
Some species like the spruce spider mite appear in early spring after overwintering as eggs. They thrive best in cool temperatures while other species like the two-spotted spider mite thrive best in dry, humid weather. The two-spotted spider mite is most active during summer and early autumn and will inflict the most damage to plants while producing several generations during these dry months.
Spider mites experience several stages including egg, larva, nymph, and adulthood. These arachnids usually lay their eggs on the underside of leaves. The eggs take a few days to develop into larvae. Overall, a spider mite takes 2-4 weeks to develop from egg to adult. The two spotted spider mite lays yellowish eggs that look like tiny pearls while spruce spider mites lay red or yellow eggs, usually on the bases of needles on coniferous plants.
Signs of a Spider Mite Infestation
Spider mites are so small they are almost microscopic. But a keen gardener can easily spot signs of a spider mite infestation if the gardener knows exactly what to look for. Though these pests are tiny, they leave significant damage in their wake and also produce telltale features when they infest your garden or lawn. Signs of spider mite infestation include the following:
- Yellow or whitish stippling on leaves
Spider mites infestation results in yellow or whitish stippling or spots on the leaves of plants. This occurs when the mites strip plants of sap and even chlorophyll.
- Bent leaves
Leaves may bend or drop due to dehydration. This occurs when large populations of spider mites suck moisture from plant cells.
- Presence of silk webbing on plants
Spider mites produce webbing on cones, leaves and other areas of plants which they attack. Look for this silk webbing to verify whether or not spider mites are present in your garden or lawn.
Spider mites are best known for their spider-like appearance and the ability to produce silk webbing. Popular species such as the spruce spider mite and two-spotted spider mite differ in color but exhibit the same spider-like characteristics while feeding on plant sap.
Removal and Preventative Procedures
Spider mites can have a deadly impact on your plants. Fortunately, there are several options available to remove as
well as prevent further infestation. These methods usually involve the use of natural or biological control measures since miticides – chemicals that kill mites – are not usually available to individuals who do not possess a pesticide applicator license.
Apply the procedures below for best results:
- Use hose or bug blaster to spray away spider mite pests from leaves.
- Create DIY insecticide soap using 1-part soap to 9 parts water and spray on affected leaves and plant surfaces.
- Quarantine new plants until mite infestation is under control
- Purchase predatory insects such as predatory mites, lacewings, and ladybugs and apply them to infested plants.
Instore or Chemical
Chemicals are available for use in controlling spider mite infestation. However, according to the Ohio State University’s insecticide control site, there are at present no effective spider mite insecticides available for over-the-counter use.