- On annual vegetable crops — such as squash, melons and watermelons — loss of leaves can have a significant impact on yield and lead to sunburning.
- On crops such as sugar peas and beans, where pods are attacked, spider mites can cause direct damage.
- On ornamentals, mites are primarily an aesthetic concern, but they can kill plants if populations become very high on annual plants. Spider mites are also important pests of field-grown roses.
Spider mites, almost too small to be seen, pass into our gardens without notice. No matter how few, each survives by sucking material from plant cells. Large infestations cause visible damage. Leaves first show patterns of tiny spots or stipplings. They may change color, curl and fall off. The mites activity is visible in the tight webs that are formed under leaves and along stems.
Large populations are often accompanied by fine webbing. Host plants are many and include strawberries, melons, beans, tomatoes, eggplant, ornamental flowers, trees and most houseplants.
Chemical pesticide use actually encourages the spread of spider mites by killing the beneficial insects that prey on them. Mites are also known to develop quick resistance to various pesticides. For these reasons, it’s important to control mites with effective natural and organic methods.
Many species of the spider mite (family: Tetranychidae), so common in North America, attack both indoor and outdoor plants. They can be especially destructive in greenhouses.
- Prune leaves, stems and other infested parts of plants well past any webbing and discard in trash (and not in compost piles). Don’t be hesitant to pull entire plants to prevent the mites spreading to its neighbors.
- Use the Bug Blaster to wash plants with a strong stream of water and reduce pest numbers.
- Commercially available beneficial insects, such as ladybugs, lacewing and predatory mites are important natural enemies. For best results, make releases when pest levels are low to medium.
- Nuke Em, a relatively new organic insecticide containing food-grade ingredients, works fast and kills most indoor gardening pests at the egg, larvae or adult stage. Best of all, it does this without leaving a residue on the leaves that can impact flavor.
- BotaniGard ES is a highly effective biological insecticide containing Beauveria bassiana, an entomopathogenic fungus that attacks a long-list of troublesome crop pests – even resistant strains! Weekly applications can prevent insect population explosions and provide protection equal to or better than conventional chemical pesticides.
- Mix Pure Neem Oil with Coco-Wet and apply every 3-5 days to kill pest eggs indoors and interrupt the reproductive cycle. Make sure to spray all plant parts, including the undersides of leaves. Do NOT apply when temperatures exceed 90˚F and wait at last six hours before turning lights on.
- If populations are high, use a least-toxic, short-lived pesticide (Take Down Spray, Doktor Doom Foggers) to reduce infestations, then release predatory mites to maintain control.
- Insecticidal soap or botanical insecticides can be used to spot treat heavily infested areas.
- On fruit trees, horticultural oil should be applied early in the season or late in the fall to destroy overwintering eggs.
- Dust on leaves, branches and fruit encourages mites. A mid-season hosing (or two!) to remove dust from trees is a worthwhile preventative.
- Water stress makes both trees and garden plants more susceptible to mite infestations. Make sure your plants are properly watered.
Mites live in colonies, mostly on the underside of leaves, and feed by piercing leaf tissue and sucking up the plant fluids. Feeding marks show up as light dots on the leaves. As feeding continues, the leaves turn yellow and may dry up and drop off.
Note: Spider mites are wind surfers. They disperse over wide areas riding their webbing on the breezes. Careful containment and disposal of infested plants is crucial.
The University of California Agricultural and Natural Resources division’s Integrated Pest Management website says the following about the damage mites cause:
Found on the undersides of leaves, these tiny plant pests can wreak-havoc on indoor and outdoor gardens. Learn methods for organic spider mite control here.
Pesticides and miticides are the best options if you need to completely rid your plants of spider mites. However, you are advised to use non-toxic, organic options for two main reasons:
These infestations tend to get worse during spring and summer. That is because the spider mite eggs can overwinter on dead leaves and fallen twigs. Once the weather gets warmer, the little buggers hatch, start eating, and mature in just a few days. They then immediately start reproducing and the circle continues. Are you starting to get a clear picture of why they can be so difficult to control?
What was an attack on one leaf quickly snowballs into a domino effect that will see the plant lose its ability to photosynthesize and repair itself. Slowly, it dies off, as the leaves fall off and the plant’s entire system stops functioning. Now imagine this happening to entire crops.
- Spider mites are tiny (about 1 mm in size)
- They tend to exclusively live on the underside of leaves
The worst part of spider mite control is populations grow so quickly and they spread so fast that by the time a farmer recognizes the first signs of an infestation, there is a good chance that it will be already too late and even spider mite killer or insecticidal soap may not be enough.
These pests are referred to as spider mites because they have a habit of making webs on the underside of plant leaves. This is also where they lay their eggs and tend to live. Spider mites only live for about four weeks. Their eggs hatch in three days and they lay a new batch every single day.
To understand the kind of damage spider mites can cause, you first must understand how a typical plant works. Healthy plants regulate their water retention through their leaves. These leaves have a vast array of stomata that tend to open and close in accordance with prevailing environmental conditions thus allowing water to either escape or be retained.
The toxic kind might also get rid of other natural predators that help keep spider mite infestations under control
Because they breed so fast, spider mites quickly develop a resistance to most pesticides and miticides. Additionally, organic pesticides and miticides are just safer for use around the house and on your farm as well. Here is a quick list of some pesticides that you should consider using to get rid of spider mites:
Spider mites tend to migrate from plant to plant and they can windsurf across different leaf clusters. Once you start seeing the telltale white and yellow spots on leaves as well as silk webs on the undersides, then you should immediately isolate those plants. Keep the rest clustered so that they maintain a moist environment in which spider mites do not thrive.
How To Get Rid Of Spider Mites 7 minutes to read | Updated for 2019 What’s In This Guide Most growers around the world know about spider mites. As part of the mite family and closely