Table 1.

Ornamental pest management using imidacloprid applied with the Kioritz soil injector1,2

PestHostAverage size (cm)Treatment dateRate (gm a.i.) 3Evaluation methodEvaluation dateResults4
% mined leaves
Birch leafminerJapanese birch13.7 dbh11/22/960.75300 leaves per tree6/2 & 6/3/970a
4/2/970.758.6 ab
1.518.7 bc
Untreated31.8 c
% mined leaves
Birch leafminerWhite birch27.9 dbh10/31/961.5500 leaves per tree5/21/973.4 a
Untreated26.4 b
% mined leaves
Hawthorn leafmining sawfly“Winter King” hawthorn6.9 dbh11/22/960.75300 leaves per tree6/16/9717.4 a
1.53.7 a
Untreated42.1 b
% stippled leaves
Azalea lace bugAzalea45.7 cm tall11/21/961.5200 leaves per plant6/16/970 a
Untreated69.5 b
# nymphs/eggs
Hawthorn lace bugCotoneaster30.5 cm tall12/2/961.54 shoots per plant7/15/970.8 a
3/28/971.59.6 a
Untreated582.1 b
% damaged leaves
Japanese beetleService berry150.0 cm tall11/22/960.75150 leaves per plant8/5/975.6 a
1.52.9 a
Untreated33.8 b
Mean # aphids
Crapemyrtle aphidCrapemyrtle5.8 dbh3/24/931.52 terminals per tree7/14/930 a
Untreated102.0 b
# honevdew drops
Painted maple aphidSilver maple71.1 dbh2/28/940.75Honeydew drops per cm29/8/940.2 a
1.50.3 a
Untreated4.2 b
% infested branches
Hemlock woolly adelgidEastern hemlock50.8 dbh11/19/961.525 branches per tree11/20/971.0 a
Untreated74.0 b
  • 1 Soil type for all studies was either loam, sandy loam, or silt loam, except for the azalea lace bug study, which was clay. Soil pH for all studies ranged from 6.3 to 8.6 with the average pH = 7.0.

  • 2 For each treatment there were 3 to 10 replications.

  • 3 Rate of imidacloprid is presented as gm active ingredient (Al) for each 2.5 cm of dbh, except for the azalea lace bug, hawthorn lace bug, and Japanese beetle trials which are presented as gm a.i. per 30.5 cm of plant height.

  • 4 Means within a column for a specific pest followed by the same letter are not significantly different by SNK (P = 0.05).