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Table 2 Mortality rates of Rhyzopertha dominica after 7, 14, and 21 days of exposure to 5 grain species treated with abamectin

From: Effects of abamectin on lesser grain borer, Rhyzopertha dominica F. (Coleoptera: Bostrichidae), infestation on some stored grains

Insecticide Rate (g kg−1) Mean mortality (% ± SE) after exposure to 5 grain species
Wheat Barley Rye Oats Triticale
After 7 days of exposure
 Abamectin 0.25 19.0 ± 0.3b* 6.5 ± 0.2b 6.5 ± 0.3b 26.5 ± 0.3a 12.0 ± 0.2b
0.5 22.0 ± 0.3b 23.5 ± 0.2a 7.5 ± 0.3b 24.0 ± 0.2a 14.5 ± 0.2b
1.0 56.5 ± 0.3a 30.5 ± 0.3a 27.5 ± 0.3a 28.5 ± 0.3a 26.5 ± 0.2a
 Infested sample 0 2.0 ± 0.1c 1.0 ± 0.1b 2.0 ± 0.1b 1.0 ± 0.1b 3.0 ± 0.1c
F   52.19 22.68 14.95 22.30 32.61
P   < 0.05 < 0.05 < 0.05 < 0.05 < 0.05
After 14 days of exposure
 Abamectin 0.25 68.5 ± 0.4b 54.0 ± 0.4b 61.0 ± 0.4a 87.5 ± 0.3a 63.5 ± 0.2b
0.5 67.0 ± 0.4b 58.5 ± 0.3b 66.5 ± 0.3a 89.0 ± 0.2a 61.0 ± 0.3b
1.0 85.0 ± 0.2a 78.50 ± 0.4a 81.0 ± 0.3a 96.5 ± 0.2a 79.0 ± 0.3a
 Infested sample 0 2.0 ± 0.1c 1.0 ± 0.1c 2.0 ± 0.1b 1.0 ± 0.1b 3.0 ± 0.1c
F   113.21 27.89 25.41 41.96 36.76
P   < 0.05 < 0.05 < 0.05 < 0.05 < 0.05
After 21 days of exposure
 Abamectin 0.25 100.0 ± 0.0a 99.0 ± 0.1a 98.5 ± 0.2a 99.5 ± 0.1a 96.5 ± 0.2a
0.5 100.0 ± 0.0a 100.0 ± 0.0a 99.0 ± 0.1a 100.0 ± 0.0a 99.0 ± 0.1a
1.0 100.0 ± 0.0a 100.0 ± 0.0a 100.0 ± 0.0a 100.0 ± 0.0a 100.0 ± 0.0a
 Infested sample 0 2.0 ± 0.1b 1.0 ± 0.1b 3.0 ± 0.1b 1.0 ± 0.1b 3.0 ± 0.1b
F   53.66 49.71 43.55 51.10 41.63
P   < 0.05 < 0.05 < 0.05 < 0.05 < 0.05
  1. *For each exposure period separately, means within columns followed by the same letter are not significantly different. Tukey-Kramer (HSD) test at P > 0.05; in all cases df = 8, 70; P < 0.05