Spider Mite Outbreaks

— Written By and last updated by

Originally posted on ecoIPM.org

Photo Jun 24, 6 07 00 p.m.

Things are heating up and the twospotted spider mite, Tetranychus urticae, thrives in hot dry weather. I have found many spider mites in the landscape on roses and many other plants. My butterfly bushes (Buddleja), which are particularly susceptible, are losing leaves (which have turned yellow anyway) due to mite damage. It is important to scout for twospotted spider mites now because they reproduce most rapidly in hot dry weather. Under these conditions they can mature from egg to reproducing adult in 5 days! Nursery crops are especially susceptible because they may be exposed to more sun than landscape plants and tolerance for damage is lower.

Orius nymph on butterfly bush leaf with spider mites. Photo: SD Frank

My plants had predatory minute pirate bug (Orius) nymphs mixed in with the spider mites but so far they were not keeping up with the rapid spider mite population growth. I rarely see spider mite webbing on plants especially outdoor plants.

buddleji damage

Twospotted spider mites feed on over 100 plant species sucking the fluid out of leaf cells. This ‘stippling’ damage can rapidly cause entire plants to take on a bronzed appearance. Look on the underside of leaves on susceptible hosts or beat foliage on a white piece of paper to scout for spider mites. If you notice mites or damage a range of control options are available the best of which are several new miticides that provide efficacy against many mite life stages. Pyrethroids can make mite populations worse by killing natural enemies. Imidacloprid can also cause spider mite outbreaks. For more information and product suggestions visit a comprehensive guide from University of Florida.

Written By

Photo of Steven Frank, N.C. Cooperative ExtensionDr. Steven FrankProfessor and Extension Specialist (919) 515-8880 steven_frank@ncsu.eduEntomology & Plant Pathology - NC State University
Updated on Jan 11, 2016
Was the information on this page helpful? Yes check No close
Scannable QR Code to Access Electronic Version This page can also be accessed from: go.ncsu.edu/readext?363262