Spider Mites

Spider Mites Spider Mites The most common spider mites that attack The most common spider mites that attack plants are two spotted spider mite (Tetranychus plants are two spotted spider mite (Tetranychus urticae) and spruce spider mite (Oligonychus urticae) and spruce spider mite (Oligonychus ununguis). These tiny arachnids feed by piercing ununguis). These tiny arachnids feed by piercing individual plant cells and removing individual plant cells and removing the contents. This causes tiny yel- the contents. This causes tiny yellow or white speckles on infested low or white speckles on infested leaves. When a large number of leaves. When a large number of these feeding spots occur near these feeding spots occur near each other, the foliage takes on a each other, the foliage takes on a yellow or bronzed appearance. Heavily infested yellow or bronzed appearance. Heavily infested plants may be discolored, stunted or even killed. plants may be discolored, stunted or even killed. Control Control • Knock spider mites off the plant with a forceful • Knock spider mites off the plant with a forceful stream of water from a hose. stream of water from a hose. • Apply insecticidal soap, being sure to cover • Apply insecticidal soap, being sure to cover both the upper and lower leaf surfaces. both the upper and lower leaf surfaces. • Use a pesticide. Spider mites are not killed by • Use a pesticide. Spider mites are not killed by regular insecticides, so be sure the pesticide regular insecticides, so be sure the pesticide label indicates it is a “miticide.” label indicates it is a “miticide.” Provided by Provided by wimastergardener.org wimastergardener.org

Additional Resources Additional Resources Spider Mites Spider Mites • UW-Extension Fact Sheet XHT1109, Spruce • UW-Extension Fact Sheet XHT1109, Spruce Spider Mite, at https://hort.uwex.edu/articles/ Spider Mite, at https://hort.uwex.edu/articles/ spruce-spider-mite/ spruce-spider-mite/ Spider Mites Spider Mites The most common spider mites that attack The most common spider mites that attack plants are two spotted spider mite (Tetranychus plants are two spotted spider mite (Tetranychus urticae) and spruce spider mite (Oligonychus urticae) and spruce spider mite (Oligonychus ununguis). These tiny arachnids feed by piercing ununguis). These tiny arachnids feed by piercing individual plant cells and removing the individual plant cells and removing the contents. This causes tiny yellow or contents. This causes tiny yellow or white speckles on infested leaves. white speckles on infested leaves. When a large number of these feed- When a large number of these feeding spots occur near each other, the ing spots occur near each other, the foliage takes on a yellow or bronzed foliage takes on a yellow or bronzed appearance. Heavily infested plants may be dis- appearance. Heavily infested plants may be discolored, stunted or even killed. colored, stunted or even killed. Control Control • Knock spider mites off the plant with a forceful • Knock spider mites off the plant with a forceful stream of water from a hose. stream of water from a hose. • Apply insecticidal soap, being sure to cover • Apply insecticidal soap, being sure to cover both the upper and lower leaf surfaces. both the upper and lower leaf surfaces. • Use a pesticide. Spider mites are not killed by • Use a pesticide. Spider mites are not killed by regular insecticides, so be sure the pesticide regular insecticides, so be sure the pesticide label indicates it is a “miticide.” label indicates it is a “miticide.” Provided by Provided by wimastergardener.org wimastergardener.org

Spider Mites Spider Mites The most common spider mites that attack The most common spider mites that attack plants are two spotted spider mite (Tetranychus plants are two spotted spider mite (Tetranychus urticae) and spruce spider mite (Oligonychus urticae) and spruce spider mite (Oligonychus ununguis). These tiny arachnids feed by piercing ununguis). These tiny arachnids feed by piercing individual plant cells and removing the individual plant cells and removing the contents. This causes tiny yellow or contents. This causes tiny yellow or white speckles on infested leaves. white speckles on infested leaves. When a large number of these feed- When a large number of these feeding spots occur near each other, the ing spots occur near each other, the foliage takes on a yellow or bronzed foliage takes on a yellow or bronzed appearance. Heavily infested plants may be dis- appearance. Heavily infested plants may be discolored, stunted or even killed. colored, stunted or even killed. Control Control • Knock spider mites off the plant with a forceful • Knock spider mites off the plant with a forceful stream of water from a hose. stream of water from a hose. • Apply insecticidal soap, being sure to cover • Apply insecticidal soap, being sure to cover both the upper and lower leaf surfaces. both the upper and lower leaf surfaces. • Use a pesticide. Spider mites are not killed by • Use a pesticide. Spider mites are not killed by regular insecticides, so be sure the pesticide regular insecticides, so be sure the pesticide label indicates it is a “miticide.” label indicates it is a “miticide.” Provided by Provided by wimastergardener.org wimastergardener.org