Effects of Imidacloprid on Spider Mite (Acari: Tetranychidae) Abundance and Associated Injury to Boxwood (Buxus spp.)

Boxwoods are one of the most widely used woody shrubs in managed landscapes, but they suffer frequent attack by the boxwood leafminer (Monarthropalpus flavus). The neonicotinoid insecticide imidacloprid is highly efficacious in reducing the abundance of M. flavus when applied as a foliar spray or a soil drench. Recent reports of elevated populations of spider mites following applications of imidacloprid to other species of woody plants prompted an investigation to determine the effects of imidacloprid on abundance of a specialist spider mite, Eurytetranychus buxi, and the resultant damage it causes. Boxwoods treated with imidacloprid housed significantly more E. buxi and sustained more discoloration than untreated boxwoods. Moreover, there was a direct relationship between the abundance of E. buxi and the amount of associated injury. Arborists and landscape managers should be aware of the potential for elevated abundance of spider mites on boxwoods and greater levels of discoloration following applications of imidacloprid.

[1]  Adrianna Szczepaniec,et al.  Neonicotinoid Insecticide Imidacloprid Causes Outbreaks of Spider Mites on Elm Trees in Urban Landscapes , 2011, PloS one.

[2]  G. Gupta,et al.  Professional and Consumer Insecticides for Management of Adult Japanese Beetle on Hybrid Tea Rose , 2007, Journal of economic entomology.

[3]  Adrianna Szczepaniec,et al.  Residual Toxicity of Imidacloprid to Hawthorn Lace Bug, Corythuca cydoniae, Feeding on Cotoneasters in Landscapes and Containers , 2007 .

[4]  P. Shrewsbury,et al.  Beat sampling accuracy in estimating spruce spider mite (Acari: Tetranychidae) populations and injury on juniper. , 2004, Journal of economic entomology.

[5]  Adrianna Szczepaniec,et al.  Incidence, Abundance, and Severity of Mites on Hemlocks Following Aplications of Imacloprid , 2004, Arboriculture & Urban Forestry.

[6]  M. Raupp,et al.  Application of Systemic Insecticides in Relation to Boxwood Leafminer's Life History , 2001, Arboriculture & Urban Forestry.

[7]  W. Cranshaw,et al.  Observations of Population Increases and Injury by Spider Mites (Acari: Tetranychidae) on Ornamental Plants Treated with Imidacloprid , 1998 .

[8]  Clifford S. Sadof,et al.  Limitations of cost-benefit-based aesthetic injury levels for managing twospotted spider mites (Acari: Tetranychidae) , 1993 .

[9]  R. Gagné.  The plant-feeding gall midges of North America , 1989 .

[10]  J. Holmes,et al.  Integrated Pest Management for Arborists: Implementation of a Pilot Program , 1984, Arboriculture & Urban Forestry.

[11]  Adrianna Szczepaniec.  Mechanisms underlying outbreaks of spider mites following applications of imidacloprid , 2009 .

[12]  C. A. Chiriboga.  Physiological responses of woody plants to imidacloprid formulations , 2009 .

[13]  M. Raupp,et al.  prOpHyLACTIC pESTICIDE AppLICATIONS AND LOW SpECIES DIVErSITy: DO THEy CrEATE pEST OUTBrEAKS IN THE UrBAN FOrEST? , 2007 .

[14]  S. Frank,et al.  Does Imidacloprid Reduce Defoliation by Japanese Beetles on Linden for More Than One Growing Season? , 2007 .

[15]  R. Lehman.  Spruce spider mite, Oligonychus ununguis (Jacobi) - an integrated approach to management Acarina:Tetranychidae , 2002 .

[16]  P. Shrewsbury,et al.  EVALUATION OF THE SYSTEMIC INSECTICIDES IMIDACLOPRID AND THIAMETHOXAM APPLIED AS SOIL APPLICATIONS FOR CONTROL OF BOXWOOD LEAFMINER ON BOXWOOD, 2000-2001 , 2002 .

[17]  Leon G. Higley,et al.  Economic thresholds for integrated pest management. , 1996 .

[18]  J. C. Schread.  Leaf Miners and Their Control , 1971 .