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

Egyptian Journal of Biological Pest Control

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

Insecticide	Rate (g kg⁻¹)	Mean mortality (% ± SE) after exposure to 5 grain species
Insecticide	Rate (g kg⁻¹)	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

*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