Spider mites are common, tiny garden pests, related to spiders and ticks. Usually microscopic, mites can be found in almost any habitat, including the human body. We refer to some mites based on where they are found: cheese mites, dust mites, eyelash mites.
The term “spider mite” is often used to refer to mites that attack plants. For instance in Oregon, spruce mite is a common pest of spruce and a few other trees. The two-spotted spider mite is a spider mite that feeds on many types of plants. The following information pertains specifically to two-spotted spider mite, and may also be true for other plant-feeding mites.
Spider mites thrive in hot, dry weather and cause damage to many types of ornamental and vegetable plants. In this article you will find information about:
Spider mites are a common and extremely frustrating pest for anyone growing cucumbers. These tiny sap-sucking creatures can quickly get out of control, causing major damage to your cucumber plants. In this comprehensive guide, we’ll provide key information on identifying, preventing, and eliminating spider mites on cucumber plants.
What Are Spider Mites?
Spider mites are not actually insects, but tiny arachnids closely related to spiders. There are many species, with the two-spotted spider mite being most common. Adults are less than 1 mm long and vary in color from yellowish-green to red.
Spider mites live in colonies, mostly on the undersides of leaves They use needle-like mouth parts to pierce plant cells and suck out the contents. This results in stippling, yellow spots, browning, and leaf loss Spider mites thrive in hot, dry conditions.
Signs of Spider Mite Damage on Cucumber Plants
- Small stippling spots or yellowing on leaves
- Browning and drying of leaves
- Premature leaf drop
- Fine webbing on leaves or stems
If you suspect spider mites examine the undersides of leaves closely. You may see the mites themselves which are just barely visible to the naked eye. Catching infestations early is crucial to protect your cucumber plants.
How to Prevent Spider Mites on Cucumber Plants
Prevention is the best medicine when it comes to spider mites Here are some key ways to help avoid infestations
- Keep plants consistently watered – spider mites thrive on drought stressed plants
- Prune out any infested leaves/stems immediately
- Consider using row covers as a physical barrier
- Release beneficial predatory insects like ladybugs or lacewings
- Avoid excessive nitrogen fertilization which produces soft, susceptible growth
- Wash plants with a strong spray of water to dislodge mites
Safe, Natural Ways to Get Rid of Spider Mites
If prevention fails and mites gain a foothold, act quickly using gentle, non-toxic methods:
-
Insecticidal soap: This natural soap disrupts mites’ cellular membranes. Spray cucumber plants thoroughly every 5-7 days.
-
Neem oil: Extracted from the neem tree, this oil coats mites to prevent feeding and egg laying. Apply weekly.
-
Horticultural oil: These oils smother mites on contact. Use a 1-2% solution, spraying all leaf surfaces.
-
Predatory mites: Release mite species that feast specifically on spider mites. They are voracious predators that establish colonies.
-
Strong water spray: Blast plants daily with water to detach and kill mites. Pay extra attention to the undersides of leaves.
Focus on getting complete coverage of all plant surfaces when treating. Always follow label directions. For heavy infestations, it often takes multiple applications to get the mite population under control.
When to Use Pesticides for Spider Mites
Spider mites frequently develop resistance to chemical pesticides. Their populations can actually increase after pesticide use kills off natural predatory insects and mites. For this reason, only use pesticides as an absolute last resort if all other options have failed.
If you must use a traditional pesticide, opt for the least toxic choices like insecticidal soaps, horticultural oils, or neem oil. Spot treat only the most heavily infested areas. After treatment, release predatory mites or insects to reestablish natural control.
Avoid broad spectrum pesticides that kill all insects indiscriminately. Also be aware that many traditional miticides and pesticides are highly toxic to bees. Always follow label precautions carefully.
Removing Severely Infested Cucumber Plants
In cases of severe infestations, the most effective option is often to pull up heavily damaged plants entirely. This curbs the source of the exploding mite population. Just be sure to dispose of the plants immediately in sealed bags or by burning – do not add them to the compost pile.
For milder cases, prune off just the most badly infested leaves and stems. Regularly check surrounding plants and treat at the very first signs of mites before they get out of hand. Early intervention is key.
Spider mites spell trouble for any cucumber grower. The best plan of attack is premised on preventive measures like proper watering, releasing beneficial insects, and prompt removal of early infestations before they spread.
If mites become established, use gentler tactics like horticultural oils and insecticidal soaps. Always target the undersides of leaves. While not a cure-all, these methods help reduce mite numbers so natural predatory insects can take over.
With persistence and a multi-pronged approach, you can gain the upper hand over destructive spider mites and protect your cucumber crop. Just be vigilant in scouting for the very first signs of infestation. By staying on top of spider mites, you can successfully grow healthy, productive cucumber plants.
Conditions that allow spider mites to thrive
Spider mites thrive in hot, dry weather. Ideal conditions for spider mites are temperatures in the 80s (F) and above, and low humidity (less than 50%). However, populations can build up any time humidity is lower than 90%. When these conditions persist—and especially when nights are also warm—a new generation of spider mites develops every 5–7 days. Small size that makes mites hard to see and fast population growth combine to make it seem as if large numbers of mites appeared overnight.
Drought-stressed plants are easily damaged by spider mites. In crops where both drought stress and spider mites are present, crop loss of 50% or more is possible.
Mite flare is often attributed to pesticides killing predatory insects and mites that would have otherwise kept the mites in check.
Another situation that contributes to large spider mite populations is the use of particular broad-spectrum chemicals for other insect pests. When such pesticides are applied to control other pests, it sometimes contributes to a condition called mite flare, whereby mite populations surge.
Mite flare is often attributed to pesticides killing predatory insects and mites that would have otherwise kept the mites in check. It can also happen because some insecticides cause mites to reproduce more quickly than they otherwise would (spider mites are not insects). Therefore, consider using “soft” pesticides that are of reduced risk in harming beneficial insects and mites.
Chemicals with low environmental impact
- Insecticidal soap. For soap to be effective, it must cover mites’ bodies. It may be necessary to move leaves around and upside down to get good coverage. Soap must usually be applied multiple times for effective control. Apply a thorough spray over the entire plant, then again 2–3 days later to cover the new mites that have hatched (eggs are not affected by a soap spray).
- Neem oil. Apply as for soap to cover mites’ bodies. To protect pollinators, avoid using neem oil when plants are blooming;
- When temperatures exceed 80°F, both soap and neem oil can further damage plants. Test a small area of the plant before applying these products during high temperatures.
- Find specific chemical options in the “PNW Handbook” Chemical Control of Landscape Pests | Pacific Northwest Pest Management Handbooks.
- Numerous chemical products available to the homeowner are effective against spider mites. Most are contact products: the chemical must directly contact the mites’ bodies to work. It’s usually necessary to apply a thorough spray, more than once, for effective control.
- As always, read product labels carefully. Apply product at exactly the rate outlined on the label to reduce pesticide resistance — spider mites are notorious for building up resistance when the same product is used repeatedly. The pesticide label will also have information regarding appropriate temperatures for treatment.
How to Grow Cucumbers – Insect Dust & Peppermint Oil Spray Mix: Spider Mites & Cucumber Beetles
FAQ
How do you get rid of spider mites on cucumber plants?
Use a strong jet of water to knock off spider mites from the leaves. Make sure to get the undersides of the leaves where they often hide. Apply insecticidal soap, which suffocates the mites. Make sure to cover all surfaces of the plant. Repeat every 5-7 days as needed. Neem oil is an effective natural pesticide.
What is the best treatment for spider mites?
If a treatment for mites is necessary, use selective materials, preferably insecticidal soap or insecticidal oil. Both petroleum-based horticultural oils and plant-based oils such as neem, canola, or cottonseed oils are acceptable.
Can a plant recover from spider mites?
Plants with mite damage limited to a few leaves will usually recover without special care. But plants stressed by more significant spider mite damage will require extra attention. Make sure your plant gets the appropriate amount of sunlight. Keep soil moisture consistent so the soil is never soggy or too dried out.
Is vinegar good for spider mites on plants?
Step 2: How to Treat Spider Mites on Lucky Bamboo
This works for mild infestations. This is effective also: Mix 1/4 cup apple cider vinegar (white vinegar is fine too) with 1 cup of water, 1 t of baking soda & a few drops of mild dish soap into a spray bottle.