Table 3.

Comparison of chlorantraniliprole and imidacloprid as a basal soil drench targeting boxwood psyllid and box-wood leafminer on established boxwoods in Lexington Cemetery.

TreatmentApplication datezPsyllidsLeafminers
Damaged twigs (of 20)y% reductionMined leaves (of 100)x% reduction
ChlorantraniliproleOctober7.3 ± 1.261 ± 30
ImidaclopridOctober0.5 ± 1.0*88.96 ± 4*89.7
ChlorantraniliproleApril4.8 ± 3.470 ± 18
ImidaclopridApril2.0 ± 1.40.8 ± 0.8*98.7
Untreated4.5 ± 3.761 ± 20
  • z Applications were in October 2009 or April 2010.

  • y Mean (±SE) no. of twigs (out of 20) with current year’s showing psyllid damage (cupped terminal leaves); evaluated July 2010.

  • x Based on five leaves from each of 20 randomly selected twigs per shrub; evaluated 13 October 2010.

  • Notes: ANOVA results: for psyllids, F4,20 = 7.5, P < 0.001; for leafminers, F4,14 = 4.2, P < 0.02. Asterisk (*) denotes significant reduction relative to untreated check (Dunnett’s test, P < 0.05).