Table 1 Comparison of critical elements in bitrophic feeding trials of both studies
From: A controversy re-visited: Is the coccinellid Adalia bipunctata adversely affected by Bt toxins?
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% | |