Laboratory studies on the effects of pollen from Bt-maize on larvae of some butterfly species
Authors: Felke, M., Lorenze, N., Langenbruch, G.-A.
Journal, Volume, Year: Journal of Applied Entomology, volume 126:320-325, 2002
The effects of Bt 176 pollen consumption were quantified for larvae of three nontarget lepidopterans (Pieris brassicae, Pieris rapae, and Plutella xylostella). Food plants were dosed with a defined amount of corn pollen. Mortality was assessed, along with chronic effects of development, growth, and behavior (feeding). Leaf consumption decreased for P. xylostella with increasing pollen but not so clearly for P. rapae or P. brassicae. P. rapae and P. brassicae gained less weight with increased pollen. The mortality rate for P. xylostella increased linearly with increasing pollen, but this relationship was not as clear for P. rapae and brassicae. LD50s were 19.2 pollen/leaf (P. xylostella), 39.0 (P. rapae), and 139.2 (P. brassicae). LD50 values were not very good, with wide confidence intervals.
Study showed a variety of tolerance between species. Also showed chronic effects with somewhat low amounts of pollen. Although the methodology for determining amount of pollen applied was robust, it is uncertain if all of the pollen was consumed.