The species involved in the experiment were freshly hatched neonates of the Cowpea Seed Beetle (Callosobruchus maculatus) and L1 of Northern Corn Rootworm (Diabrotica barberi), Western Corn Rootworm (Diabrotica virgifera) and Southern Corn Rootworm (Diabrotica undecimpunctata howardi).
The experimental design included a bioassay per species, per treatment, per rate and all replicated twice. The treatments were the lead construct (the RNA-based biocontrol candidate for CPB), a control and a positive control. The rates tested for the lead construct were 2x, 1x and 0.005x the field application rate. The plates were scored on day 3 and day 7 at approximately the same time.
The bioassays were setup and rated using Syngenta’s standard bioassay screening procedures, although this was not a GLP experiment. When ascertaining whether the test subjects were alive or dead, they would be poked and subsequently observed for movement. The mortality was calculated per replicate as {sum of dead test subjects/(sum of all test subjects)}.
]]>For the Diabrotica tests, the subject was exposed to 1x and 2x the field application rate, with 2 replications. For the CPB tests, the subject was exposed to 0.5x, 0.05x, and 0.005x the field application rate, with 2 replications.
The bioassays were setup and rated using Syngenta’s standard bioassay screening procedures, although this was not a GLP experiment.
The mortality was calculated per replicate as {sum of dead test subjects/(sum of all test subjects)}.
]]>The experiment consisted of two treatments of lead construct and control, with 36 insects each. The beetles were exposed to a rate that would result in 100% mortality in a Colorado Potato Beetle bioassay. The plates were scored daily around the same time except for the weekend (hence no data on day 6 and 7). The plate wells were refreshed with a non-treated leaf disc at day 3.
The bioassays were setup and rated using Syngenta’s standard bioassay screening procedures, although this was not a GLP experiment. When ascertaining whether the test subjects were alive or dead, they would be poked and subsequently observed for movement. An internal negative control was taken in every experiment. As an internal standard, control mortality had to stay below 20% to be considered as a robust assay. Control mortality was 0% and 5.5% respectively on day 12.
The survival was calculated per replicate as {sum of alive test subjects/(sum of all test subjects)}.
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