English ivy, also known as Hedera helix, is one of 25 species of ivy grown in the United States. The University of Florida reports that this plant is the most popular ivy in this country and that it is used both indoors and outdoors. Many cultivars of English ivy exist; each demonstrates slight differences in the shape, color and size of leaves and the way it grows. Insect pests include aphids, mealybugs and spider mites.
English ivy and Irish ivy are similar plants, both of which belong to the Hedera genus. Both of these species of ivy originated in Asia and Europe and were widely introduced to temperate climates around the world as a landscape plant. According to the King County, Washington, website, this plant first appeared in the American Pacific Northwest in the late 19th century. Unfortunately, it has escaped cultivation and become a problem as an invasive species by growing up into the tree canopy.
What Are Spider Mites?
Colorado State University reports on its website that spider mites are common garden pests. They belong to the insect family known as Tetranychidae and are classified arachnids, as are spiders, scorpions and ticks. These are very small insects that you might not notice until a large colony exists on your plant. They range in color from yellow to green, brown and red. Different species of spider mites have varying appearances and the insect's color can change from season to season.
What to Watch For
Because you might not be able to see spider mites with your naked eye, you'll need to watch for the webbing they create on your plant to determine if you have an invasion of this destructive insect. When a spider mite population becomes large, their webs can be quite noticeable. It gives both the insects and their eggs protection from the weather and their enemies. Your plant will develop leaves that appear flecked, bronzed and scorched. Leaf loss will occur when an infestation becomes severe and plant death can result.
Controlling Spider Mites: Natural Enemies
The Colorado State University website states that the widespread use of insecticides has killed some of the natural predators of spider mites. If your outdoor English ivy becomes the victim of spider mites, you can purchase ladybugs and release them in your yard near your English ivy. Most of the ladybugs will disappear, but some will remain as long as their favorite foods exist. Other beneficial insects that prey on spider mites include predatory mites, big-eyed bugs, minute pirate bugs and predatory thrips. Some of these insects are available for purchase through specialty catalogs and websites.
Controlling Spider Mites: Cultural Methods, Natural Sprays and Insecticides
The Flower Shop Network website recommends cutting off affected leaves from your English ivy plant. When you have a known insect problem, it's wise to bag your cut plant parts and dispose of them in your local landfill and not your compost pile, where they can breed an even larger population. Colorado State University suggests keeping your ivy well watered during dry spells and also shooting your plant with a sharp stream of water to knock these insects off. The Flower Shop Network advises the use of insecticidal soap spray. If you decide to use a chemical miticide, repeat your application every 10 to 14 days because such products do not kill spider mite eggs.