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Table 1
Comparison of critical elements in bitrophic feeding trials of both studies
Critical elements		Alvarez-Alfageme et al. [8]	Schmidt et al. [1]

Parameter/methods	Number of test insects	Not clear, probably 34 to 41	30
	Number of replicates	Not clear, probably 1	4
	Total number of test insects per treatment	N = 34 to 41	N = 120
	Diet treatment	Water/sugar solution (2 droplets) with Bt toxin	Meal moth eggs treated with Bt toxin in buffer solution
	Diet control	Water/sugar solution (no buffer added) Untreated meal moth eggs	Meal moth eggs treated with empty constructs in buffer solution Meal moth eggs treated with buffer solution (3 separate control treatments; see below)
	Dose(s) of administered Bt toxins	1 each	3 each (for each Bt-concentration treatment, a separate control was carried out; 3 control treatments)
	Exposure time (per instar) to Bt toxin	4 × 1 day (1 day during each instar followed by recovery periods) Total development time 12 days (Bt) to 17 days (other treatments)	9 to 10 days continuous (all instars) Total development time 9 to 10 days
	Exposed life stages	Partially, all 4 instars	Continuously, all 4 instars
	ELISA with A. bipunctata larvae to verify uptake	No	No
	Quantification of ingested amount of Bt toxin	No	No
Results	Control mortality (%)	Number of control treatments = 1	Number of control treatments = 3 + 3 pBD10 = 6
		L1-P = 15.0%	L1-P = 15.8%, 21.7%, 10.8% (15.0%, 13.3%, 10.8%) L1-A = 16.7%, 21.7%, 14.2% (15.8%, 15.0%, 14.2%)
	Treatment mortality (%)	1 dose of each Bt toxin	3 doses of each Bt toxin
	Cry1Ab	45	5	25	50
	concentration	μg/ml	μg/ml	μg/ml	μg/ml
	L1-P	20.6%	26.7%	48.3%	35.8%
	P	3.7%	1.2%	1.6%	0
	L1-A	24.3%	27.5%	49.2%	35.8%
	Cry3Bb	200	5	25	50
	concentration	μg/ml	μg/ml	μg/ml	μg/ml
	L1-P	17.1	21.7%	32.5%	30.0%
	P	0	0	1.2%	1.2%
	L1-A	17.1	21.7%	33.5%	30.8%

ELISA, enzyme-linked immunosorbent assay.
Hilbeck et al. Environmental Sciences Europe 2012 24:10 doi:10.1186/2190-4715-24-10

Table 1